Chromatographic retention-activity relationships for prediction of the toxicity pH-dependence of phenols

An investigation of the use of the chromatographic retention (log k) as an in vitro approach for modeling the pH-dependence of the toxicity to Guppy of phenols is developed. A data set of 19 phenols with available experimental toxicity-pH data was used. The importance of the mechanism of toxic action (MOA) of phenols was studied. log k data at three pH values were used for the phenols classification and two groups or 'MODEs' were identified. For one 'MODE' a quantitative retention-activity relationship (QRAR) model was calculated. Finally, the model was used to assess the toxicity to Guppy of phenols at different pH values. The results of this investigation suggest that chromatographic retention data allows fish toxicity modeling, in the 5.5-8 pH range of interest.     

Consolidation of degraded ornamental porous limestone stone by calcium carbonate precipitation induced by the microbiota inhabiting the stone

Although it has already been shown that calcareous stone can be consolidated by using a bacterially inoculated culture medium, a more user-friendly method is the in situ application of a sterile culture medium that is able to activate, among the microbial community of the stone, those bacteria with a potential for calcium carbonate precipitation. In order to test this new method for stone consolidation, non-sterilized decayed porous limestone was immersed in sterile nutritional media. Results were compared to those of the runs in which stone sterilized prior to the treatment was used. The effects of the microbial community on stone consolidation were determined by recording the evolution of the culture media chemistry. The treated stone was tested for mechanical resistance and porosity. Results demonstrate that the tested media were able to activate bacteria from the microbial community of the stone. As a consequence of the growth of these bacteria, an alkalinization occurred that resulted in calcium carbonate precipitation. The new precipitate was compatible with the substrate and consolidated the stone without pore plugging. Therefore, a good candidate to in situ consolidate decayed porous limestone is the application of a sterile culture medium with the characteristics specified in the present study.     

Measures of ozone concentrations using passive sampling in forests of South Western Europe

Ambient ozone concentrations were measured with passive samplers in the framework of the EU and UN/ECE Level II forest monitoring programme. Data from France, Italy, Luxembourg, Spain and Switzerland are reported for 2000-2002, covering the period from April to September. The number of plots increased from 67 in 2000 to 83 in 2002. The year 2001 experienced the highest ozone concentrations, reflecting more stable summer meteorological conditions. Average 6-month ozone concentrations above 45 ppb were measured this year in 40.3% of the plots, in contrast with the less than 21% measured in the other 2 years. Gradients of increasing ozone levels were observed from North to South and with altitude. Comments are made on the regional trends and on the time frame of the higher ozone episodes. Also, some recommendations enabling a better comparison between plots are provided.     

Effect of composted sewage sludge application to soil on sweet pepper crop (Capsicum annuum var. annuum) grown under two exploitation regimes

The aim of this study is to monitor the effect of the application of three increasing amounts of composted sewage sludge (3, 6 and 9 kg compost m(-2)) on the physico-chemical properties of a horticultural calcareous soil where sweet pepper plants (Capsicum annuum var. annuum) cv. California were grown. A comparative study of two different exploitation regimes was carried out; the first was an open-air field-grown plot and the second plot was kept under controlled conditions in a greenhouse. Changes in physical and chemical properties measured in soil and sweet pepper crop were recorded during crop growth in order to measure the evolution of these properties as a consequence of increasing compost applications. Organic matter, total nitrogen Kjeldahl and available phosphorus contents increased in soil after composted sewage sludge applications. The 9 kg compost m(-2) application promoted the appearance of deleterious effects on the properties of soil, such as salt accumulation, a significant increase in the electrical conductivity and an input of heavy metals (Pb>Cr>Cd). The 6 kg compost m(-2) application provided a supply of nutrients necessary to grow peppers plants under both exploitation regimes. Pepper fruit biomass production under greenhouse was almost 60% higher compared to that of the open-air plot. Lower contents of Ca and increased levels of Cu in fruit under greenhouse growing conditions compared to those of open-air grown peppers seemed to promote the occurrence of blossom-end rot, affecting more than 10% of the harvested fruits.     

Sharing goals by timely communication improves fishermen's satisfaction with marine protected areas: A case study in the Mediterranean

Marine protected areas (MPAs) are considered as a valid tool for mitigating the impact of fishing on marine ecosystems. Their success depends upon their acceptance by implicated stakeholders and on the integration of the stakeholder groups into their management. This integration is especially important with regard to fishermen, whose interests are the most directly affected by MPAs. The relational coordination method posits that effective communication and supportive relationships among stakeholders result in positive stakeholder behaviors and a more effective management of the system. Applying its principles, we designed a survey to evaluate the satisfaction of fishermen associated with five MPAs in the Spanish Mediterranean and determine what mechanisms affect fishermen’s acceptance of MPAs. Our results demonstrate that effective communication is particularly important for good supportive relationships and satisfaction among fishermen and other stakeholder groups, as well as satisfaction with the MPA. Sharing objectives with fishermen through timely communication is the primary mechanism to improve fishermen''s satisfaction and ameliorate perceptions towards MPA. To address this issue, we recommend more substantial integration of fishermen in the co-management of MPAs.     

太湖饮用水源地金墅港、渔洋山水质综合评价

采用BP神经网络、内梅罗指数和综合营养状态指数评价了太湖金墅港、渔洋山饮用水源地水质及综合营养状态。结果表明,2012年金墅港和渔洋山的水质基本达到国家Ⅱ类水要求,其水质均处于中营养状态(31.43~47.66),不同水期对水源地营养状态影响较大,丰水期水质综合营养状态指数最低,且变化较小。渔洋山的年均富营养化状况(42.08)比金墅港(40.62)略重。     

Hydrogeological definition and applicability of abandoned coal mines as water reservoirs

Hydrogeologically, the Central Coal Basin (Asturias, Spain) is characterized by predominantly low-permeability materials that make up a multilayer aquifer with very low porosity and permeability values, where the sandstones act as limited aquifers, and wackes, mudstones, shales and coal seams act as confining levels. Preferential groundwater flow paths are open fractures and zones of decompression associated with them, so the hydraulic behaviour of the system is more associated with fracturing than lithology. Thus, abandoned and flooded mines in the area acquire an important role in the management of water resources, setting up an artificial "pseudo-karst" aquifer. This paper evaluates the potential application of the abandoned mines as underground reservoirs, both for water supply and energetic use, mainly through heat pumps and small hydropower plants. In particular, the groundwater reservoir shaped by the connected shafts Barredo and Figaredo has been chosen, and a detailed and multifaceted study has been undertaken in the area. The exposed applications fit with an integrated management of water resources and contribute to improve economic and social conditions of a traditional mining area in gradual decline due to the cessation of such activity.     

Automatic habitat classification methods based on satellite images: A practical assessment in the NW Iberia coastal mountains

Although remote sensing is increasingly in use for habitat mapping, traditional image classification methods tend to suffer shortcomings due to non-normality of spectral signatures, as well as overlapping and heterogeneity in radiometric responses of natural and semi natural vegetation. Methods using non-parametric classifiers and object-oriented analysis have been suggested as possible solutions for overcoming these limitations. In this paper, we aimed at evaluating the performance of some of these techniques for the European Natura 2000 network of protected areas habitats mapping. For this purpose, we tested different methods of supervised image classification in the Northern Mountains of Galicia, Spain, an area included in the Natura 2000 network, which is characterized by a highly heterogeneous landscape. Methods involved the use of maximum likelihood and nearest neighbour decision rules in per-pixel and per-object classification analyses on Landsat TM imagery. Per-object classifications were completed using the segment mean and segment means plus standard deviation feature spaces. The results showed the existence of significant differences in the accuracies for the different methodologies, their strengths and weaknesses and identified the most adequate approach for habitat mapping. Analyses pointed out that significant improvements in accuracy were achieved only under certain combinations of per-object analysis, non-parametric classifiers and high dimensionality feature space.     

Genotoxic effects and gene expression in <Emphasis Type="Italic">Danio rerio</Emphasis> (Hamilton 1822) (Cypriniformes: Cyprinidae) exposed to mining-impacted tributaries in Manizales,Colombia

The zebrafish (Danio rerio) is one of the most studied aquatic organisms for water biomonitoring, due to its sensitivity to environmental degradation and resistance to toxic substances. This study determined the presence of micronuclei and nuclear abnormalities in peripheral blood erythrocytes, and assessed the gene expression of caspase-3 (CASP-3) and metallothionein 1 (MT-1) in the gills and liver of D. rerio. The study fish (n = 45) were exposed to water collected from two stations with mining impact (E2 and E3) and a reference station without evident mining contamination (E1), all located in La Elvira stream (Manizales-Colombia). In addition, a positive control (PC) with HgCl₂ (50 μg/L) and negative control (NC) with tap water were included. The fish from the PC and E2 and E3 treatments displayed genotoxic effects and changes in gene expression, with significant differences in micronuclei formation and the presence of blebbed nuclei. The cytochrome oxidase subunit I (COI) gene was used as reference and proved to be stable compared to the β-actin and 28S ribosomal RNA (28S) genes. In gills, CASP-3 expression was higher in the PC, and MT-1 expression was higher in the PC and E3 treatment. In liver, CASP-3 was expressed in the E2 treatment, and MT-1 expression was low. These results show that the genotoxic effects and differential gene expression observed in fish exposed to water from La Elvira stream could also be affecting the organisms present in this habitat.     

Buccal micronucleus cytome assay of populations under chronic heavy metal and other metal exposure along the Santiago River,Mexico

The Santiago River is one of the most contaminated rivers in Mexico, with heavy metal levels above the allowed limits. Scientific evidence indicates that chronic heavy metal exposure leads to cytogenotoxic effects. The aims of this study were to evaluate the genotoxic and cytotoxic effects of such exposure in buccal mucosa cells by micronucleus (MN) assay and to identify other nuclear abnormalities (NAs), such as nuclear buds (NBUDs), binucleated cells (BNs), pyknotic nuclei (PNs), karyorrhexis (KX), karyolysis (KL), and abnormally condensed chromatin (CC). Assays were performed on samples from four populations located alongside the Santiago River that are under chronic exposure to heavy metals and other metals (HMMs), and the results were compared with those of a population without exposure to HMMs. The exposed group showed increased frequencies of NAs (KX, CC, and KL), which are associated with cytotoxic damage, and NBUDs, which are associated with genotoxic damage. Increased frequencies of NBUDs and CC were observed in subjects from El Salto/Juanacatlán, Ocotlán, and Paso de Guadalupe, and an increase in KX frequency was observed in subjects from El Salto/Juanacatlán. Significant differences in KL frequency were observed in subjects from La Barca, El Salto/Juanacatlán, Paso de Guadalupe, and Ocotlán. Predictors for increased development of MNs and NBUDs were high concentrations of Al, Zn, and Cu. In conclusion, chronic exposure to HMMs, especially Al, Cu, and Zn, in the studied population could be related to increased frequencies of NAs, such as NBUDs, KX, CC, and KL, in the buccal mucosa cells.