Using FTIR to corroborate the identity of functional groups involved in the binding of Cd and Cr to saltbush (Atriplex canescens) biomass

Fourier transform infrared (FTIR) studies were performed to confirm the chemical modification of saltbush (Atriplex canescens) biomass and to provide information about the identity and binding characteristics of the chemical groups responsible for the binding of Cd(II), Cr(III), and Cr(VI). In addition, studies were performed to determine the optimum time for the binding of the three ions by saltbush biomass, and to study the efficiency of HCl and sodium citrate as stripping agents. The metal quantification was performed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The results showed that 10 min or less is enough to achieve the maximum metal binding, and that aqueous solutions of 0.1 mM HCl or sodium citrate were enough to strip more than 80% of the bound Cd. It was determined that more than 70% of the bound Cr(III) was stripped using 0.1 mM HCl. Chemical modification of carboxyl and ester groups on the biomass was performed. The FTIR results confirmed that the esterification of carboxyl groups and hydrolysis of ester groups in the native biomass had occurred. The direct effect of these modifications on the binding properties of the biomass provided strong evidence that the carboxyl functionality is the main group responsible for binding Cd and Cr(III). However, the IR data showed that for Cr(VI), a different type of functional group is involved.     

Fuzzy input–output model for optimizing eco-industrial supply chains under water footprint constraints

Global water stress is expected to increase due to population growth, economic development and climate change. Because of this trend, there is an increased interest in the water intensity of industrial activities conducted via the product supply chain or within specified geographical boundaries or regions, both at the enterprise- or regulatory-level. The total water footprint of economic activities should be evaluated in consideration of local water resource consumption, virtual water trade and resource availability. As individual entities seek to protect their respective interests, the challenge is to optimize inter-regional trade of goods with the consideration of the interests of participants in the network. This work presents a fuzzy input–output model for optimizing supply chains under water footprint constraints. Two case studies, involving tile manufacturing and biofuel production, are considered to demonstrate the use of the model.     

Regional patterns of microsatellite variation in <Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis> from the Iberian Peninsula

The Almería-Oran Oceanographic Front (AOOF) has been proposed as an effective marine barrier to gene flow between the NE Atlantic Ocean and the Mediterranean Sea for several species. Previous studies using allozymes and mitochondrial DNA have reported a scenario of secondary intergradation between populations of Mytilus galloprovincialis from those basins, with the allelic frequencies of some loci showing abrupt clinal patterns across the AOOF. In this study, we aimed at testing the congruence between six neutral polymorphic microsatellites versus previous data on allozymes and mtDNA-RFLPs, at depicting the population structure of this species in the Iberian Peninsula. Microsatellite genotyping was scored on 17 samples of mussels collected in the Iberian coast, including some areas not sampled before. Microsatellites exhibited larger intrabasin diversity (F _SC = 1.72%, ), similar interbasin differentiation (F _CT = 2.81%) and fewer allelic clines than allozymes or mtDNA haplotypes. These results fully support the scenario of secondary intergradation with some ongoing gene flow between basins, as proposed in previous analyses. Moreover, this congruence between markers and analyses separated by a 12-year period (1988–2000) confirm the temporal stability of this marine barrier at shaping the Iberian phylogeographic break in M. galloprovincialis. In addition, the genetic continuity between the NE Atlantic (Portugal) and the Alboran Sea seems to be warranted across the Gulf of Cadiz and the Gibraltar strait after the present microsatellite data. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Mass scans from a proton transfer mass spectrometry analysis of air over Mediterranean shrubland browsed by horses

Plants usually emit large amount and varieties of volatiles after being damaged by herbivores. However, analytical methods for measuring herbivore-induced volatiles do not normally monitor the whole range of volatiles and the response to large herbivores such as large mammals is much less studied than the response to other herbivores such as insects. In this paper we present the results of using a highly sensitive proton transfer reaction-mass spectrometry (PTR-MS) technique that allows simultaneous monitoring of leaf volatiles in the pptv range. The resulting mass scans in air over Mediterranean shrubland browsed by horses show 70 to 100% higher concentrations of the masses corresponding to mass fragments 57, 43 and 41 (mostly hexenals, acetone and acetic acid) than scans over control non-browsed shrubland. These compounds are biogeochemically active and they are significant components of the volatile organic carbon found in the atmosphere. They influence the performance of living organisms and, the chemical and physical processes of Earth's atmosphere.     

Contribution of fishery discards to the diet of the Black-browed albatross (Thalassarche melanophris) during the non-breeding season: an assessment through stable isotope analysis

Black-browed albatrosses (Thalassarche melanophris) disperse over the Argentinean Continental Shelf and neighboring waters during their non-breeding season. It is one of the most frequent seabirds attending fishing vessels and also the most common Procellariform in the bycatch of longliners and trawlers in the area. Understanding the use of fishery discards by this species is an important issue when assessing the potential effect of strategic discard management in decreasing the abundance, interactions, and mitigating mortality. In the present study, we analyzed carbon and nitrogen stable isotope compositions in the blood of Black-browed albatrosses to assess the relative contribution of discards from different fisheries to the diet of this species in winter. Samples were obtained in winter 2011 from fishing vessels operating between 41–43°S and 57–59°W. No sex differences in δ¹³C and δ¹⁵N were observed. Results indicate that during their non-breeding season, isotopic signatures of Black-browed albatrosses are closer to discards and offal generated by fisheries and in particular by trawlers. The large fishing effort of trawl fisheries in Argentina highlights the urgency of an exhaustive analysis to find practical and effective ways to reduce the number of seabirds attending trawlers.     

Biomonitoring of cadmium, chromium, nickel and arsenic in general population living near mining and active industrial areas in Southern Tunisia

The human health impact of the historic and current mining and industrial activities in Tunisia is not known. This study assessed the exposure to metals in the population of Southern Tunisia, using biomonitoring. The aim of this pilot study was to evaluate metal exposure on 350 participants living near mining and active industrial areas in the South of Tunisia. Blood specimens were analyzed for metals (Cd, Cr, As, and Ni) by Atomic Absorption Spectrometer equipped with Zeeman background correction and AS-800 auto sampler by graphite furnace and graphite tubes with integrated L'vov platform. The sample population was classified according to different age groups, sex, smoking habit, sea food and water drinking consumption, occupational exposure, amalgam fillings and place of residence. The blood As, Cd, Cr and Ni values expressed as mean?±?SD were 1.56?±?2.49, 0.74?±?1.15, 35.04?±?26.02 and 30.56?±?29.96 μg/l, respectively. Blood Cd and Ni levels in smokers were 2 and 1.2 times, respectively, higher than in non-smokers. Blood Cd levels increase significantly with age (p?=?0.002). As, Cd and Ni were significantly correlated with gender and age (p?<?0.05). Cd level in blood samples of subjects occupationally exposed was 1.3 times higher than that of non-exposed. Blood metals were not significantly affected by amalgam fillings, place of living and sea food and drinking water consumption. This first biomonitoring study of metal exposure in the South of Tunisia reveals a substantial exposure to several metals. The pathways of exposure and health significance of these findings need to be further investigated.     

Towards a framework for assessment and management of cumulative human impacts on marine food webs

Effective ecosystem‐based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the food web components, and assessed the components’ vulnerability to those threats. Some threats had high (e.g., coastal infrastructure) or low impacts (e.g., agricultural runoff) on all food web components, whereas others (e.g., introduced carnivores) had very different impacts on each component. Partitioning the ecosystem into its components enabled us to identify threats previously overlooked and to reevaluate the importance of threats commonly perceived as major. By incorporating this understanding of system vulnerability with data on changes in the state of each threat (e.g., decreasing domestic pollution and increasing fishing) into a food web model, managers may be better able to estimate and predict cumulative human impacts on ecosystems and to prioritize conservation actions.