Toenail cerium levels and risk of a first acute myocardial infarction: the EURAMIC and heavy metals study

The association between cerium status and risk of first acute myocardial infarction (AMI) was examined in a case-control study in 10 centres from Europe and Israel. Cerium in toenails was assessed by neutron activation analysis in 684 cases and 724 controls aged 70 years or younger. Mean concentrations of cerium were 186 and 173 microg/kg in cases and controls, respectively. Cerium was positively associated with low socio-economic status, smoking, mercury, zinc and scandium (p0.001). Cases had significantly higher levels of cerium than controls after adjustment for age and centre (case-control ratio 1.074; 95% CI 1.002-1.151) and increased in further adjustment for other cardiovascular risk factors 1.085; 95% CI 1.025-1.149. The risk after adjustment for age and centre was higher with increasing cerium levels (p for trend=0.02). After adjustment for BMI, history of hypertension, smoking, alcohol intake, diabetes, family history of CHD, beta-carotene, lycopene, alpha-tocopherol, selenium, mercury and scandium, the OR for the highest quintile was 1.43 (95% CI 0.85-2.41; p-trend 0.08). When we applied this same model in non-smokers the odds ratios in the 4th and 5th quintiles of cerium as compared with the lowest were 2.09 (95% CI 1.05-4.16) and 2.81 (95% CI 1.21-6.52), respectively, p-trend 0.011. Our results suggest that toenail cerium levels may be associated with an increased risk of AMI, but more research is warranted to shed further light and fully understand the plausibility and public health implications of these findings.     

Degradation kinetics of butyltin compounds during the bioremediation of contaminated harbour sediments

The present study was aimed at the reclamation of harbour sediments contaminated with butyltin compounds (BTCs) by means of biostimulation and/or bioaugmentation experiments carried out in a 5-L slurry bioreactor. In the biostimulation experiment with inorganic nutrients, almost 50% of TBT was degraded in 20 weeks. In the bioaugmentation experiment with a microbial consortium, no significant degradation of TBT was observed. Conversely, bioaugmentation combined with biostimulation led to a decrease of ～50% in TBT after four weeks. A simple kinetic model fitted to the experimental data of BTC concentration allowed us to estimate that 10 weeks are needed to decrease BTC contamination by 90% using a strategy based on both biostimulation and bioaugmentation, and 29 weeks for a strategy using biostimulation only. Overall, our study indicates that strategies based on biostimulation coupled to bioaugmentation can be effective in significantly reducing the concentration of BTCs over relatively short timescales.     

Climate change,marine policy and the valuation of Mediterranean intertidal ecosystems

This commentary describes a gap in the qualitative and quantitative knowledge of the provision of benefits to humans from the intertidal ecosystems of the Mediterranean and offers a framework for quantification of the benefits provided by these systems. The identification of such benefits, understanding their spatial distribution and their subsequent quantification will be critical to the design of policy responses to future climate change, sea level rise and seawater acidification. A baseline understanding of the current state of ecosystem functions, as well as of the provision of related ecosystem services, is therefore needed. Further, researchers must strive to generate forecasts of the changes in these functions and services conditional on policy responses and the range of expectations for climate change.     

Robotic testing of radio frequency devices designed for industrial safety

An experimental setup is proposed to test the performance of safety devices based on radio frequency technology. The setup specifically tests devices designed for improving safety in dangerous areas of small size, such as those surrounding power press brakes. Tested here is a radio frequency identification (RFID) prototype, whose main objective is to prevent accidents by sending a stop signal to a machine when a worker’s wrist, bearing an RFID tag, gets too close to the dangerous area. An ABB IRB 2400L robot is used as a reference system; this system is capable of providing millimeter accuracy. A plastic hand and a wristband with at least one passive RFID tag are attached to the end of the robot arm, which emulates the behavior of a human arm. With this robotic approach, it is possible to test trajectories with different velocities and orientations and to simulate several risky situations associated with machine use. Several experiments are presented that were conducted with the RFID prototype, and statistics are reported on the distance detection capability of this safety system with respect to the plane that defines the dangerous area. A matrix approach is proposed for analyzing the robustness of safety devices that are designed to automatically prevent a worker entering in dangerous areas. The results show the benefits that development of a radio frequency device of this class could confer towards increasing worker safety.     

Separation of plastic waste via the hydraulic separator Multidune under different geometric configurations

The recovery of high-quality plastic materials is becoming an increasingly challenging issue for the recycling sector. Technologies for plastic recycling have to guarantee high-quality secondary raw material, complying with specific standards, for use in industrial applications. The variability in waste plastics does not always correspond to evident differences in physical characteristics, making traditional methodologies ineffective for plastic separation. The Multidune separator is a hydraulic channel allowing the sorting of solid particles on the basis of differential transport mechanisms by generating particular fluid dynamic conditions due to its geometric configuration and operational settings. In this paper, the fluid dynamic conditions were investigated by an image analysis technique, allowing the reconstruction of velocity fields generated inside the Multidune, considering two different geometric configurations of the device, Configuration A and Configuration B. Furthermore, tests on mono- and bi-material samples were completed with varying operational conditions under both configurations. In both series of experiments, the bi-material samples were composed of differing proportions (85% vs. 15%) to simulate real conditions in an industrial plant for the purifying of a useful fraction from a contaminating fraction. The separation results were evaluated in terms of grade and recovery of the useful fraction.     

Spatio-temporal analysis of alpine ecotones: A spatial explicit model targeting altitudinal vegetation shifts

There is general agreement in literature that Alpine vegetation belt ecotones have shown a trend of upward migration in the last few decades. Despite the potential of such shifts as indicators of global change effects in mountain ecosystems, there are relatively few works focused on their assessment in a systematic and spatially explicit way. In this work our aim is to quantify the altitudinal shifts and analyse the spatial pattern dynamics of mountain ecotones. We developed a novel procedure to delineate the current and former state of three characteristic mountain ecotones, which we formalised as forest, tree and tundra lines. Our approach is based on the recognition of altitudinal extreme outposts identified with ecotone locations at a slope scale. The integration of multi-temporal datasets allows the identification and quantification of altitudinal advances and retreats in the outpost locations for a given period. We tested the method in a section of the Italian Alps for the period 1957-2003. Results show a general trend of an increase in altitude for the three ecotones, despite the occurrence of occasional decreases. We estimate decadal altitude increments of 25 m for forest line, 13 m for treeline and 11 m for tundra line. We also identified changes in ecotone spatial morphology between the two dates, with significant implications in connectivity and colonisation dynamics.     

Assessment of groundwater quality by means of self-organizing maps: application in a semiarid area

The Kohonen neural network was applied to hydrochemical data from the Detritic Aquifer of the Lower Andarax, situated in a semiarid zone in the southeast of Spain. An activation map was obtained for each of the sampling points, in which the spatial distribution of the activated neurons indicated different water qualities. To extract the information contained in the activation maps, they were divided into nine quadrats. Cartesian coordinates were assigned to each quadrant (x, y), and for each sampling point, three derived variables were selected, which were assigned the values x and y of the corresponding quadrat. A classification was defined based on this simple matrix system which allows an easy and rapid means of evaluating the water quality. This assessment highlights the various processes that affect groundwater quality. The method generates output that is easier to interpret than from traditional statistical methods. The information is extracted from the activation maps without significant loss of information. The method is proposed for assessing water quality in hydrogeochemically complex areas, where large numbers of observations are made.     

Roadside habitats: a missing link in the conservation agenda

Roadside habitats in Brazil have been and remain major suppliers of biological diversity and plant genetic resources to society. If the ultimate demise of these habitats is to be avoided, their inclusion in conservation policy planning is mandatory.     

Heavy metal accumulation by the halophyte species Mediterranean saltbush

To identify Cd- and Zn-accumulating plants exhibiting a high growth rate, seeds from the halophyte species Mediterranean saltbush (Atriplex halimus L.) were collected on a heavy-metal-contaminated site in southeastern Spain (Llano del Beal, Cartagena). Seedlings from this ecotype were exposed for 3 wk to 0.1 mM Cd or Zn in a nutrient solution in a fully controlled environment. All plants remained alive and no significant growth inhibition was recorded until the end of the experiment. Mean Cd and Zn accumulation in aerial parts was 830 and 440 mg kg(-1), respectively, and the rate of metal translocation even increased with the duration of stress exposure. Resistance to heavy metals in this species may be partly linked to precipitation of Cd in oxalate crystals in the stems. A Cd-induced decrease in glutathione concentration also suggests that phytochelatins overproduction may occur in these conditions. We conclude that Mediterranean saltbush, which is able to produce up to 5 Mg dry matter ha(-1) yr(-1), may be an effective species for phytoextraction and should be tested for this purpose in field conditions.     

Root growth and metal uptake in four grasses grown on zinc-contaminated soils

Depth and area of rooting are important to long-term survival of plants on metal-contaminated, steep-slope soils. We evaluated shoot and root growth and metal uptake of four cool-season grasses grown on a high-Zn soil in a greenhouse. A mixture of biosolids, fly ash, and burnt lime was placed either directly over a Zn-contaminated soil or over a clean, fine-grained topsoil and then the Zn-contaminated soil; the control was the clean topsoil. The grasses were 'Reliant' hard fescue (Festuca brevipila R. Tracey), 'Oahe' intermediate wheatgrass [Elytrigia intermedia (Host) Nevski subsp. intermedia], 'Ruebens' Canada bluegrass (Poa compressa L.), and 'K-31' tall fescue (Festuca arundinacea Schreb.). Root growth in the clean soil and biosolids corresponded to the characteristic rooting ability of each species, while rooting into the Zn-contaminated soil was related to the species' tolerance to Zn. While wheatgrass and tall fescue had the strongest root growth in the surface layers (0-5 cm) of clean soil or biosolids, wheatgrass roots were at least two times more dense than those of the other grasses in the second layer (5-27 cm) of Zn-contaminated soil. When grown over Zn-contaminated soil in the second layer, hard fescue (with 422 mg/kg Zn) was the only species not to have phytotoxic levels of Zn in shoots; tall fescue had the highest Zn uptake (1553 mg/kg). Thus, the best long-term survivors in high-Zn soils should be wheatgrass, due to its ability to root deeply into Zn-contaminated soils, and hard fescue, with its ability to effectively exclude toxic Zn uptake.