Tolerance of Mediterranean seagrasses (<Emphasis Type="Italic">Posidonia oceanica</Emphasis> and <Emphasis Type="Italic">Cymodocea nodosa</Emphasis>) to hypersaline stress: water relations and osmolyte concentrations

The present study examines for the first time the effects of increased salinity on water relations and osmolyte (carbohydrates and amino acids) concentrations in two Mediterranean seagrass species, Posidonia oceanica and Cymodocea nodosa, which are adapted to growth in environments with contrasting salinity and have a known differential sensitivity to alterations in ambient salinity. The specific aim was to obtain insights into their respective capacities to cope with natural or anthropogenically induced (e.g. desalination plants) hypersaline stress and its ecological implications. To this end, large plant fragments of both seagrass species were maintained for 47 days in a laboratory mesocosm system under ambient salinity (37 psu; control) and three chronic hypersaline conditions (39, 41 and 43 psu). Analyses of leaf-tissue osmolality indicated that both species followed a dehydration avoidance strategy, decreasing their leaf water potential (Ψ_w) as the external salinity increased, but using different physiological mechanisms: whereas P. oceanica leaves exhibited a reduction in osmotic potential (Ψ_π), C. nodosa leaves maintained osmotic stability through a decrease in turgor pressure (Ψ_p) probably mediated through cell-hardening processes. Accordingly, the concentrations of soluble sugars and some amino acids (mainly Pro and Gly) suggested the activation of osmoregulatory processes in P. oceanica leaves, but not in C. nodosa leaves. Osmotic adjustments probably interfered with leaf growth and shoot survival of P. oceanica under hypersaline stress, whereas C. nodosa showed a more efficient physiological capacity to maintain plant performance under the same experimental conditions. These results are consistent with the more euryhaline ecological behaviour of C. nodosa and contribute to understanding the high vulnerability shown by P. oceanica to even mild increments in seawater salinity.     

A compilation of field surveys on gaseous elemental mercury (GEM) from contrasting environmental settings in Europe,South America,South Africa and China: separating fads from facts

Mercury is transported globally in the atmosphere mostly in gaseous elemental form (GEM, \( {\text{Hg}}_{\text{gas}}^{0} \) ), but still few worldwide studies taking into account different and contrasted environmental settings are available in a single publication. This work presents and discusses data from Argentina, Bolivia, Bosnia and Herzegovina, Brazil, Chile, China, Croatia, Finland, Italy, Russia, South Africa, Spain, Slovenia and Venezuela. We classified the information in four groups: (1) mining districts where this contaminant poses or has posed a risk for human populations and/or ecosystems; (2) cities, where the concentration of atmospheric mercury could be higher than normal due to the burning of fossil fuels and industrial activities; (3) areas with natural emissions from volcanoes; and (4) pristine areas where no anthropogenic influence was apparent. All the surveys were performed using portable LUMEX RA-915 series atomic absorption spectrometers. The results for cities fall within a low GEM concentration range that rarely exceeds 30 ng m^?3, that is, 6.6 times lower than the restrictive ATSDR threshold (200 ng m^?3) for chronic exposure to this pollutant. We also observed this behavior in the former mercury mining districts, where few data were above 200 ng m^?3. We noted that high concentrations of GEM are localized phenomena that fade away in short distances. However, this does not imply that they do not pose a risk for those working in close proximity to the source. This is the case of the artisanal gold miners that heat the Au–Hg amalgam to vaporize mercury. In this respect, while GEM can be truly regarded as a hazard, because of possible physical–chemical transformations into other species, it is only under these localized conditions, implying exposure to high GEM concentrations, which it becomes a direct risk for humans.     

Modelling spatial patterns of correlations between concentrations of heavy metals in mosses and atmospheric deposition in 2010 across Europe

Background

This paper aims to investigate the correlations between the concentrations of nine heavy metals in moss and atmospheric deposition within ecological land classes covering Europe. Additionally, it is examined to what extent the statistical relations are affected by the land use around the moss sampling sites. Based on moss data collected in 2010/2011 throughout Europe and data on total atmospheric deposition modelled by two chemical transport models (EMEP MSC-E, LOTOS-EUROS), correlation coefficients between concentrations of heavy metals in moss and in modelled atmospheric deposition were specified for spatial subsamples defined by ecological land classes of Europe (ELCE) as a spatial reference system. Linear discriminant analysis (LDA) and logistic regression (LR) were then used to separate moss sampling sites regarding their contribution to the strength of correlation considering the areal percentage of urban, agricultural and forestry land use around the sampling location. After verification LDA models by LR, LDA models were used to transform spatial information on the land use to maps of potential correlation levels, applicable for future network planning in the European Moss Survey.

Results

Correlations between concentrations of heavy metals in moss and in modelled atmospheric deposition were found to be specific for elements and ELCE units. Land use around the sampling sites mainly influences the correlation level. Small radiuses around the sampling sites examined (5 km) are more relevant for Cd, Cu, Ni, and Zn, while the areal percentage of urban and agricultural land use within large radiuses (75–100 km) is more relevant for As, Cr, Hg, Pb, and V. Most valid LDA models pattern with error rates of <?40% were found for As, Cr, Cu, Hg, Pb, and V. Land use-dependent predictions of spatial patterns split up Europe into investigation areas revealing potentially high (=?above-average) or low (=?below-average) correlation coefficients.

Conclusions

LDA is an eligible method identifying and ranking boundary conditions of correlations between atmospheric deposition and respective concentrations of heavy metals in moss and related mapping considering the influence of the land use around moss sampling sites.

     

Symmetric Renegotiation-Proof Climate Agreements

Environmental Modeling & Assessment - In this paper, we study the impacts and effects of the number of countries and green technology on climate agreements. In a repeated climate game...     

土地利用与可持续建筑:巴西南部的设计与建造

最近几年,位于马西南部的里奥格兰德联合大学的研究生土木工程项目开展了一些与建筑环境的可持续性有关的活动.其中一些活动与教育有关,一些活动与设计和建造有关.本文介绍了应用可持续性原则的项目的总体概念框架及其主要总体目标.新近的一个项目(对一所技术学校的提议)说明了如休在一个具体的项目处理框架及其目标问题1.文章也简要介绍了其他研究和设计活动.并简单讨论了把可持续性问题纳入发发中国家的土地利用规划以及项目设计的障碍.     

Technological behaviour and leaching tests in ceramic tile bodies obtained by recycling of copper slag and MSW fly ash wastes

Journal of Material Cycles and Waste Management - The substitution of standard clays to residues, in this case copper smelter slag and fly ashes coming from the incineration process of MSW in...     

Biogeochemical characterization of surface waters in the Aljustrel mining area (South Portugal)

Aljustrel mining area (South Portugal) is a part of the Iberian Pyrite Belt and encloses six sulfide mineral masses. This mine is classified of high environmental risk due to the large tailings’ volume and acid mine drainage (AMD)-affected waters generated by sulfides’ oxidation. The use of biological indicators (e.g., diatoms) revealed to be an important tool to address the degree of AMD contamination in waters. Multivariate analysis has been used as a relevant approach for the characterization of AMD processes. Cluster analysis was used to integrate the significant amount and diversity of variables (physicochemical and biological), discriminating the different types of waters, characterized by the high complexity occurring in this region. The distinction of two main marked phenomena was achieved: (1) the circumneutral-Na-Cl water type (sites DA, PF, BX, BF, RO, CB), expressing the geological contributions of the Cenozoic sediments of Sado river basin, with high diatom diversity (predominating brackish diatoms as Entomoneis alata); and (2) the acid–metal-sulfated water type (sites BM, JU, RJ, AA, MR, BE, PC, AF), reflecting both the AMD contamination and the dissolution of minerals (e.g., silicates) from the hosting rocks, potentiated by the extremely low pH. This last group of sites showed lower diatom diversity but with typical diatoms from acid- and metal-contaminated waters (e.g., Pinnularia aljustrelica). In addition to these two water types, this hierarchical classification method also allowed to distinguish individual cases in subclusters, for example, treated dams (DC, DD), with alkaline substances (lime/limestone), that changed the physicochemical dynamics of the contaminated waters.

     

Influence of phytase addition to poultry diets on phosphorus forms and solubility in litters and amended soils

Diet modification to decrease phosphorus (P) concentration in animal feeds and manures can reduce surpluses of manure P in areas of intensive animal production. We generated turkey and broiler litters from two and three flock trials, respectively, using diets that ranged from "high" to "low" in non-phytate phosphorus (NPP) and some of which contained feed additives such as phytase. Phosphorus forms in selected litters were analyzed by sequential chemical fractionation and solution (31)P nuclear magnetic resonance (NMR) spectroscopy. Selected litters were also incubated with four contrasting soils. Reducing dietary NPP and using phytase decreased total P in litters by up to 38%. Water-soluble phosphorus (WSP) in litters was decreased 21 to 44% by feeding NPP closer to animal requirement, but was not affected by phytase addition. Solution (31)P NMR spectroscopy showed that feeding NPP closer to requirement decreased orthophosphate in litters by an average of 38% and that adding phytase to feed did not increase the concentration of orthophosphate in litters. Phytase also decreased phytate P in litters by 25 to 38%, demonstrating that it increases phytate P hydrolysis. Incorporation of litters with soils at the same total P rate increased WSP in soils relative to the control; this increase was correlated to soluble P added with litters at 5 d, but not by 29 d. Changes in soil Mehlich-3 phosphorus (M3-P) were related to total P added in litter, rather than soluble P. We conclude that feeding NPP closer to requirement and using feed additives such as phytase decrease total P concentrations in litters, while having little effect on P solubility in litters and amended soils.     

From the traditional concept of safety management to safety integrated with quality

This editorial reviews the evolution of the concepts of safety and quality that have been used in the traditional workplace. The traditional programs of safety are explored showing strengths and weaknesses. The concept of quality management is also viewed. Safety management and quality management principles, stages, and measurement are highlighted. The concepts of quality and safety guarantee are assessed. Total Quality Management concepts are reviewed and applied to safety quality. Total safety management principles are discussed. Finally, an analysis of the relationship between quality and safety from data collected from a company in Spain is presented.     

SELECTION OF WASTE DISPOSAL SITES USING GIS1

ABSTRACT: Geographic Information Systems (GIS) technology is used to identify candidate sites for a solid waste disposal facility in the Gölbasi region of Turkey that has suffered from the negative impact of a current but poorly-located open-dump site on the environment. The municipality of Gölbasi has noticed its deleterious effect on the environment, and has thus decided to dismiss this open-dump site and search for new landfill sites. In this study, the procedure followed under a GIS framework rejects the unacceptable sites considering environmental factors exclusively, other than economic and political issues, contained in the form of multiple layers of attribute information to select the candidate sites for landfilling wastes through an overlay analysis performed by GIS software, ARC/INFO V 7.1. For the spatial data requirements of GIS, a number of thematic map layers (ground water, wetlands and swamp areas, surface water, roads, topographic contours, ecological features, settlements, erosion susceptibility zones, and soil type) are prepared in digital form. In this application, GIS is considered as a screening tool in a site selection process to narrow the number of candidate sites, subsequently leading to one or more sites for detailed investigation. Preliminary ranking for a group of potential sites is done on the basis of simple calculations coupled with on-site field studies.