116 research outputs found

    Comparison of structure function and detrended fluctuation analysis of wind time series

    Get PDF
    A multifractal (MF) analysis in time scale has been applied to three wind speed series presenting a different pattern. The temporal scaling properties of the records, registered each 10 minutes, were studied using two different methods, structure function (SF) and detrended fluctuation analysis (DFA), to establish a comparison of the results and their interpretation in the geostrophic turbulence context. A systematic analysis of the exponent of the structure function (ζ(q)) and the generalized Hurst exponents (H(q)) gave, in general terms, equivalent results when a comparison is applied among the three months. However MF DFA presented statistically more robust results. This allowed us to see a clear difference between the parameters studied for each month: linear component of ζ(q) (ζ(q = 1) = H), intermittency of the wind series (μ), deviation from linear structure function (λ), Hurst exponent (H(q = 2)) and H(q) dependence on q (ΔH)

    Assesing heavy metals in the marine bivalve Pinna nobilis in the Balearic Islands (western Mediterranean)

    Get PDF
    Heavy metals (Cd, Cu, Hg, Pb and Zn) concentration were determined in the marine bivalve Pinna nobilis along the Balearic Islands, comparing a protected area with two sites with strong anthropogenic influence. Analyses of Cabrera and Mallorca indicated that heavy metal concentration were generally higher in the most of samples, specially in Santa Maria bay (Cabrera, MPA), and Magaluf (Mallorca, with strong anthropogenic influence). Pinna nobilis appears to efficiently bioaccumulate heavy metals exhibiting large differences in a range of anthropic scenarios. The results on P. nobilis metal accumulation show that the concentrations decrease according to order: Zn > Cu >Pb> Cd > H

    Alto contenido de metales en el molusco Pinna nobilis en el Archipiélago Balear (Mediterráneo occidental) y una revisión de las concentraciones en bivalvos marinos (Pinnidae)

    Get PDF
    Summary: Concentrations of metals (Cd, Cu, Hg, Pb and Zn) in the marine bivalve Pinna nobilis at several coastal locations of Majorca and the Cabrera Islands (Mediterranean Sea) were investigated. The elevated concentrations of metals found in the soft tissues of P. nobilis indicate high bioaccumulation factors. All concentrations and the calculated metal pollution index showed significant differences between sites, with particularly high concentrations in the Cabrera Archipelago, a marine protected area (MPA). The datasets were evaluated with the limited information published in the literature for Pinnidae species worldwide. In benthic P. nobilis, concentrations of Cd, Cu and Zn are more than 30 times higher and Hg and Pb concentrations are 4 and 7 times higher, respectively, than concentrations in other bivalve species, such as Mytilus galloprovincialis (Mytilidae). These observations from species inhabiting nearby ecological habitats of the coastal environment (Pinnidae vs. Mytilidae) are also discussed in the context of current marine monitoring strategies and assessmentsResumen: Se investigaron las concentraciones de metales (Cd, Cu, Hg, Pb y Zn) en el bivalvo marino Pinna nobilis en diferentes localidades costeras de las Islas de Mallorca y Cabrera (Mar Mediterráneo). Las elevadas concentraciones de metales que se encontraron en los tejidos blandos de P. nobilis revelaron una elevada bioacumulación. Las concentraciones de metales estudiadas, así como el índice de contaminación por metales (ICM) mostraron diferencias significativas entre los sitios, con concentraciones particularmente altas en el archipiélago de Cabrera, un área marina protegida (AMP). Se realizó una revisión bibliográfica de la escasa información publicada sobre las especies de la familia Pinnidae a nivel mundial. En comparación con otras especies de bivalvos, como Mytilus galloprovincialis (Mytilidae), la especie bentónica P. nobilis presentó concentraciones más de 30 veces superiores para Cd, Cu y Zn; y hasta 4 y 7 veces para Hg y Pb, respectivamente. La información recabada sobre estas especies que habitan en ecosistemas costeros (Pinnidae vs. Mytilidae) es discutida en el contexto de las actuales estrategias marinas de seguimiento y evaluaciónVersión del editor1,006

    Sono-enzymatically embedded antibacterial silver-lignin nanoparticles on cork filter material for water disinfection

    Get PDF
    Providing clean drinking water is a great challenge worldwide, especially for low-income countries where the access to safe water is limited. During the last decade, new biotechnological approaches have been explored to improve water management. Among them, the use of antimicrobial nanoparticles for designing innovative centralized and decentralized (point-of-use) water treatment systems for microbial decontamination has received considerable attention. Herein, antimicrobial lignin capped silver nanoparticles (AgLNP) were embedded on residual cork pieces using high-intensity ultrasound coupled with laccase-mediated grafting to obtain biofunctionalized nanomaterial. The developed AgLNP-coated cork proved to be highly efficient to drastically reduce the number of viable Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in liquid medium. Additionally, the coated-cork was characterized using FTIR-ATR spectroscopy and SEM imaging, and further used as a filter bed in a point-of-use device for water disinfection. The constructed water filtering system significantly reduced the amount of viable E. coli and resistant Bacillus cereus spores from filtered water operating at increasing residence times of 1, 4, 6, 16, 24, and 48 h. Therefore, the presented results prove that the obtained cork-based antimicrobial nanocomposite material could be used as a filtering medium for the development of water filtration system to control pathogen dissemination.Peer ReviewedPostprint (published version

    BREAKING THE PARADIGM: MARINE SEDIMENTS HOLD TWO-FOLD MICROPLASTICS THAN SEA SURFACE WATERS AND ARE DOMINATED BY FIBERS

    Get PDF
    Marine compartments are often considered independent environments in studies on plastic pollution (Ali et al., 2021). Consequently, little is known about microplastic (MPs) distribution amongst those habitats closely linked. Here, we perform an interactive assessment of MPs abundance and composition from the pelagic habitat to beaches integrating shallow seafloor sediments of a coastal Mediterranean marine protected area and evaluating MPs ingestion in holothurians, echinoderms, molluscs, and fishes inhabiting the area. We observed a gradient in the accumulation of MPs from the sea surface (0.17 ± 0.39 MPs/m2) to the seafloor (76 ± 108 MPs/m2) and beach sediment (13418 ± 28787 MPs/m2), with a skip of two orders of magnitude. Microplastic abundances fit with those reported for more anthropized Mediterranean areas and suggest coastal environments as potential debris sinking areas. Fibers dominate all the studied habitats. Holothurians showed the highest general MPs and fibers ingestion occurrence (91%), with greater values (9.48 ± 8.05 MPs/individual and 8.24 ± 7.95 fibers/individual) than those reported previously (Bulleri et al., 2021). Considering ecological key role, species distribution, and MPs ingestion values, we suggest Holothuroidea as suitable bioindicators for plastic pollution, particularly for fibers. Fibers are composed primarily of cellulose acetate (29%), whereas styrofoam of polystyrene (64%), and films, fragments, and filaments of a variable percentage of polyethylene and polypropylene. Differences found in the polymer composition amongst plastics´ morphologies are reflected in the variability observed between habitats and marine organisms. Particularly the polymer composition of fibers coincides with that of one of the MPs ingested by invertebrates. Results suggest that shape is a key plastic characteristic in determining polymer distribution patterns along with habitats and in marine species. Finally, this study highlights once again the importance and urgency of local and global actions needed to mitigate plastic pollution and particularly fiber release into the marine environment

    Multispecies Assessment of Anthropogenic Particle Ingestion in a Marine Protected Area

    Get PDF
    We have applied a multispecies ecosystem approach to analyse the ingestion of anthropogenic particles (AP) in the gastrointestinal tract of 313 individuals (17 fish species and 8 invertebrate species) from pelagic, demersal and benthic habitats in a marine protected area off the Western Mediterranean (Cabrera National Park). We have quantified and characterized the ingestion at several taxonomic levels of fish, sea urchins, sea cucumbers, bivalves, and jellyfish in relation to biotic/abiotic factors based on taxonomic groups, trophic guilds (functional groups) and habitats. AP ingestion occurrence ranged from 26 to 100% with no significant differences among taxonomic groups. The fish within the MPA showed an overall ingestion occurrence ranging from 0 to 100%, the echinoderms from 29 to 100%, the bivalves from 72 to 96% and the jellyfish 36% ingestion. The ecosystem approach applied to evaluate overall AP ingestion within the species reported that for trophic guilds, the omnivorous species ingested the highest amounts of anthropogenic items, while herbivores ingested significantly fewer items than all other trophic guilds. Moreover, no significant differences were found amongst habitats, indicating a homogeneous spatial distribution of APs at all studied habitats. The multispecies approach provided insight into the high APs exposure to species within Cabrera MPA, highlighting the potential harm linked with marine litter that threatens marine biodiversity.En prensa5,82

    Triglyceride Form of Docosahexaenoic Acid Mediates Neuroprotection in Experimental Parkinsonism

    Get PDF
    Parkinson’s disease (PD) is a neurodegenerative disorder of unknown etiology. The main treatment of PD consists of medication with dopamine-based drugs, which palliate the symptoms but may produce adverse effects after chronic administration. Accordingly, there is a need to develop novel neuroprotective therapies. Several studies suggest that omega-3 polyunsaturated fatty acids (n-3 PUFA) might provide protection against brain damage. Here, we studied several experimental models of PD, using striatal neuronal cultures, striatal slices, and mice, to assess the neuroprotective effects of docosahexaenoic acid (DHA), the main n-3 PUFA in the brain, administered in its triglyceride form (TG-DHA). Hence, we determined the beneficial effects of TG-DHA on neural viability following 6-hydroxydopamine (6-OHDA)-induced neurotoxicity, a well-established PD model. We also implemented a novel mouse behavioral test, the beam walking test, to finely assess mouse motor skills following dopaminergic denervation. This test showed potential as a useful behavioral tool to assess novel PD treatments. Our results indicated that TG-DHA-mediated neuroprotection was independent of the net incorporation of PUFA into the striatum, thus suggesting a tight control of brain lipid homeostasis both in normal and pathological conditions

    A novel ratiometric fluorescent approach for the modulation of the dynamic range of lateral flow immunoassays

    Get PDF
    The majority of lateral flow assays (LFAs) use single-color optical labels to provide a qualitative naked-eye detection, however this detection method displays two important limitations. First, the use of a single-color label makes the LFA prone to results misinterpretation. Second, it does not allow the precise modulation of the sensitivity and dynamic range of the test. To overcome these limitations, a ratiometric approach is developed. In particular, using anti-HIgG functionalized red-fluorescent quantum dots on the conjugate pad (as target dependent labels) and blue-fluorescent nanoparticles fixed on the test line (as target independent reporters), it is possible to generate a wide color palette (blue, purple, pink, red) on the test line. It is believed that this strategy will facilitate the development of LFAs by easily adjusting their analytical properties to the needs required by the specific application
    corecore