The Duero Diatom Index (DDI) for river water quality assessment in NW Spain: design and validation

Diatom indices developed in certain geographic regions are frequently used elsewhere, despite the strong evidence that such metrics are less useful when applied in regions other than that where species–environment relationships were originally assessed, showing that species have particular autoecological requirements in different geographic areas. The goal of this study was to develop a new metric, the Duero Diatom Index (DDI), aimed at monitoring water quality in Duero basin watercourses (NW Spain). In summer 2008 and 2009, a total of 355 epilithic diatom samples were collected following standard protocols. The 2008 samples were used to develop the DDI, whereas the samples collected during 2009 were used in the index testing. Weighted averages method was used to derive the autoecological profiles of diatoms with respect to pH, conductivity, biological oxygen demand, ammonia, nitrates, and phosphates. The optimum and tolerance values for the measured environmental variables were determined for 137 taxa with abundances and frequencies of occurrence above 1 %, and subsequent trophic indicator and sensitivity values were defined for the DDI. The correlation between the observed and the diatom-inferred nutrient concentrations was highest for phosphates (ρ _S?=?0.72). Significant statistical relationship were observed between DDI values and the chemistry-based General Quality Index values (p?=?0.006) and the specific pollution index (SPI) diatom metric (p?=?0.04). DDI has demonstrated a better correlation with water chemistry than SPI diatom metric.     

Supramolecular complex formation,a possible antigenotoxic mechanism of glucomannan against aflatoxin B1

Abstract

Glucomannan is a highly branched polysaccharide with glycosidic linkages, constituted of mannoses and glucoses. In recent years, its usefulness due to its immunological, antioxidant and antimutagenic activity has been recognized. The aim of the study was to determine the antigenotoxic ability of glucomannan extracted from Candida utilis orally administered (100–700?mg/kg) to mice, which subsequently received 1?mg/kg aflatoxin B₁. Hepatocytes obtained from these animals 4–16?h post administration were examined by means of the comet assay. The antigenotoxic effect was found to be higher than that observed in previous studies with α-mannan and β-D-glucan isolated from Saccharomyces cerevisiae., In order to explore the possibility of formation of a supramolecular complex between glucomannan and aflatoxin B₁, both compounds were co-crystallized, their melting points determined, and the complex analyzed through ultraviolet spectroscopy. The spectroscopy data suggest that the protective effect of glucomannan is related to the formation of a supramolecular complex between the two compounds.     

Nanomaterials for water cleaning and desalination,energy production,disinfection, agriculture and green chemistry

Nanomaterials may help to solve issues such as water availability, clean energy generation, control of drug-resistant microorganisms and food safety. Here we review innovative approaches to solve these issues using nanotechnology. The major topics discussed are wastewater treatment using carbon-based, metal-based and polymeric nanoadsorbents for removing organic and metal contaminants; nanophotocatalysis for microbial control; desalination of seawater using nanomembranes; energy conversion and storage using solar cells and hydrogen-sorbents nanostructures; antimicrobial properties of nanomaterials; smart delivery systems; biocompatible nanomaterials such as nanolignocellulosis and starches-based materials, and methods to decrease the toxicity of nanomaterials. Significantly, here it is reviewed two ways to palliate nanomaterials toxicity: (a) controlling physicochemical factors affecting this toxicity in order to dispose of more safe nanomaterials, and (b) harnessing greener synthesis of them to bring down the environmental impact of toxic reagents, wastes and byproducts. All these current challenges are reviewed at the present article in an effort to evaluate environmental implications of nanomaterials technology by means of a complete, reliable and critical vision.     

Source characterisation and mid-term spatial and temporal distribution of polycyclic aromatic hydrocarbons in molluscs along the Basque coast (northern Spain)

The variability of polycyclic aromatic hydrocarbons (PAH) measured in the soft tissues of Mediterranean mussels (Mytilus galloprovincialis) and Pacific oysters (Crassostrea gigas) are investigated. Samples were collected from estuarine waters within the Basque Country (Bay of Biscay), between 2003 and 2011. PAH bioaccumulation showed some seasonality and significant differences were observed between cold (autumn–winter) and warm (spring–summer) seasons. Sites located within the ports of Bilbao and Pasaia showed the highest PAH concentrations in molluscs, and the highest percentages of samples above the established Environmental Quality Standards and Environmental Assessment Criteria. Probably due to human activities carried out in the area, no clear trends were observed, between 2003 and 2011, for the autumn data. Since the Basque coast is an area with high population density and industrial activity, the congener profiles (which reveal the predominance of tetra-aromatics) and the diagnostic ratios identified urban/industrial combustion processes as the main PAH sources. However, natural and petrogenic sources cannot be disregarded.     

Afro-Eurasia and the Americas present barriers to gene flow for the cosmopolitan neustonic nudibranch Glaucus atlanticus

Pelagic species have been traditionally thought to occupy vast, genetically interconnected, geographic ranges in an essentially homogeneous environment. Although this view has been challenged recently for some mesopelagic planktonic taxa, the population structure of hyponeustonic (surface-drifting) species remains unknown. Here, we test the hypothesis of panmixis in Glaucus atlanticus, a cosmopolitan neustonic nudibranch, by assessing the genetic differentiation of multiple representatives from a global neustonic sampling effort. Specimens were collected from all subtropical oceanic gyre systems (North Atlantic, South Atlantic, North Pacific, South Pacific, and Indian Ocean). We sequenced a fragment of the mitochondrial cytochrome oxidase I gene for 98 individuals and performed population structure, differentiation (analysis of molecular variance, spatial analysis of molecular variance, F _ST, Jost’s D), and molecular clock analyses. Our results indicate that G. atlanticus is not globally panmictic, but that populations appear to be panmictic within ocean basins. We detected several topologically ectopic haplotypes in the Atlantic Ocean, but the molecular clock analysis indicates that these have diverged from closely related Indo-Pacific haplotypes over 1.2 MYA, coinciding with cooling in waters around in the southern tip of Africa and resulting oceanographic changes. These data and the fact that G. atlanticus is not known from polar latitudes suggest that gene flow between ocean basins is hindered by physical barriers (supercontinents) and water temperatures in the Arctic and Southern Oceans.     

Strategic Environmental Assessment of the Effects of European Union's Regional Development Plans in Doñana National Park (Spain)

The European Union's Structural Funds are implemented by means of Regional Development Plans (RDP), whose regionally scoped environmental assessment is required. We highlight the deficiencies faced by this approach when subregional areas with high conservation natural values are involved and illustrate it with the case of the RDP of Andalusia region on Doñana National Park area (Spain). Commissioned by the World Wildlife Fund, a Strategic Environmental Assessment (SEA) of the Andalusian RDP was carried out focusing on Doñana and its area of influence. This is a complex space where some of the most environmentally valuable features in the continent coexist with a surrounding intense and multi-sector economic activity, threatening its conservation. In the absence of an established sustainability framework in the Region, a “trickle-down” SEA approach evidenced the need to produce a set of environmental, economic and social guidelines for sustainable management of land, against which the RDP objectives were tested for coherence. An “incremental” SEA approach was also tested, which involved the identification of 79 measures and actions stemming from the RDP provisions and other concurrent planning documents reviewed and the qualitative assessment of their individual and cumulative potential impacts on Doñana environments. In the light of the results, a set of complementary mitigating measures was proposed for inclusion in tiered stages of the planning process. Measures to avoid, reduce, remedy and monitor the major types of impact were proposed, including provisions for public participation. SEA emerges as an instrument for non-governmental organizations (NGOs) to carry out independent assessment of public development initiatives.     

Energy consumption analysis of ABS plastic parts injected in a hybrid injection moulding machine

The energy analysis of injection moulding processes is influenced by complex interactions amongst the moulded part, its material, the injection machine, the process parameters and the environmental conditions. The availability of energy usage analyses that comprehend information on specific materials and machine kind is limited. This paper reports a study that estimates and analyses the power usage profile (PUP), the specific energy consumption (SEC), and the energy distribution at an operation level of two different injected parts made of acrylonitrile-butadiene-styrene and produced in a hybrid injection moulding machine. The methodology followed by the authors incorporates an experiment carried out in an industrial facility. A large sample size, and data-acquisition and data post-processing processes to obtain an accurate PUP and SEC are used. A breakdown of the energy consumed by the injection moulding process of the parts studied at an operation level using Sankey diagrams is discussed. The study results are used to identify strategies to reduce the energy consumed by the processes. The methodology employed, and the strategies reported could be used with other plastic parts regardless of the material and machine used. The results reported are new experimental data useful input for theoretical models.