1,095 research outputs found

    Last Bite: No Fish Oil No Footnotes

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    The exponential growth of off-shore mariculture that has occurred worldwide over the last 10 years has raised concern about the impact of the waste produced by this industry on the ecological integrity of the sea bottom. Investigations into this potential source of impact on the biochemistry of the sea floor have provided contrasting results, and no compelling explanations for these discrepancies have been provided to date. To quantify the impact of fish-farm activities on the biochemistry of sediments, we have investigated the quantity and biochemical composition of sediment organic matter in four different regions in the temperate-warm Mediterranean Sea: Akrotiri Bay (Cyprus), Sounion Bay (Greece), Pachino Bay (Italy), and the Gulf of Alicante (Spain). In these four study regions, the concentrations of phytopigments, proteins, carbohydrates, and lipids in the sediments were measured, comparing locations receiving wastes from fish farms to control locations in two different habitats: seagrass beds and soft nonvegetated substrates. Downward fluxes were also measured in all of the regions, up to 200 m from the fish farms, to assess the potential spatial extent of the impact. In all four regions, with the exception of seagrass sediments in Spain, the biochemistry of the sediments showed significant differences between the control and fish-farm locations. However, the variables explaining the differences observed varied among the regions and between habitats, suggesting idiosyncratic effects of fish-farm waste on the biochemistry of sediments. These are possibly related to differences in the local physicochemical variables that could explain a significant proportion of the differences seen between the control and fish-farm locations. Biodeposition derived from the fish farms decreased with increasing distance from the fish-farm cages, but with different patterns in the four regions. Our results indicate that quantitative and qualitative changes in the organic loads of the sediments that arise from intensive aquaculture are dependent upon the ecological context and are not predictable only on the basis of fish-farm attributes and hydrodynamic regimes. Therefore, the siting of fish farms should only be allowed after a case-by-case assessment of the ecological context of the region, especially in terms of the organic matter load and its biochemical composition

    Can Early Life Exposure to Permethrin lead to intergenerational effects?

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    Pesticides are largely used in agriculture against pests and consequently are present in fruits and vegetables. The wide presence of pesticide residues in breast milk underline the risk for the population, focalizing the long-term consequence of early life pyrethroid exposure. The significant presence of pyrethroid metabolites in the urine of population over the world confirms that their presence in food is a global problem. It has been demonstrated that there is a correlation between the environmental exposure to pesticides and the development of neurodegenerative diseases. Neonatal exposure to Permethrin (PERM), a member of the family of synthetic pyrethroids, can induce neurodegeneration (i.e. Parkinson’s –like disease) and it can cause some alterations in striatum of rats, involving both genetic and epigenetic pathways. The aim of this study was to evaluate if the rat offspring (F1 generation) exposed to a low dose of PERM from postnatal day 6 to 21, presents alterations in Nurr1 gene expression as previously observed in early life permethrin treated male rats. Moreover, global DNA methylation was analyzed in untreated early life exposed mothers and offspring (F1 generation). Methods Through Nurr1gene expression analysis and global DNA methylation assessment in both PERM-treated parents and their untreated offspring, we investigated on the prospective intergenerational effect of this pesticide. Results 33% of progeny presents the same Nurr1 alteration as rats exposed to permethrin in early life. A decrease in global genome-wide DNA methylation was measured in mothers exposed in early life to permethrin as well as in their offspring, whereas untreated rats have a hypermethylated genomic DNA. Conclutions Intergenerational PERM-induced damage on progenies has been identified for the first time. On the light of these results, pesticide residues in the food could represent a risk factor for the health of children especially in early life when the brain is still in the developing phase. Further studies are needed to elucidate the molecular mechanisms associated with the damage

    Functional role of biofouling linked to aquaculture facilities in Mediterranean enclosed locations

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    Biofouling is generally considered a serious threat for human coastal activities such as aquaculture, and the ecological role of fouling organisms associated with fish-farm cages remains one of the most debated topics in the ecological field. However, although biofouling may cause significant problems related to human health, environmental impact and financial losses, in the past decade there has been an increasing interest in developing methods to promote the growth of biofouling on artificial structures as a strategy to mitigate human impacts and reduce the organic enrichment caused by net-cage fish farming. Here we investigated the filtration activity of biofouling assemblages colonizing artificial substrata located within a harbor. The main objective of the study was to determine if and how changes in composition and functioning of biofouling may be affected by hypoxic conditions that periodically occur within the port site selected for this study. To this purpose, artificial panels were used as biofouling collectors and were brought back to the laboratory seasonally where they were divided in 3 subgroups and acclimated at 3 different oxygen levels to mimic the naturally occurring oxygenic conditions. Clearance and respiration rates of each community were measured 6 and 24 h after the beginning of each treatment. Regardless of experimental conditions, performance of the communities was affected by the seasonality and the amount of biomass recruiting on the panels, mainly composed of crustaceans, ascidians, polychaetes, seaweeds and several introduced species. Our study demonstrated that, in particular cases, fouling assemblages linked to aquaculture facilities may contribute to reducing environmental impact and at the same time may serve as input for their re-use in different disciplines

    Fish-farm impact on metazoan meiofauna in the Mediterranean Sea: Analysis of regional vs. habitat effects.

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    The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan meiofaunal response to fish-farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of Posidonia oceanica and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat-specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of meiofaunal taxa. In vegetated habitats, meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic system

    High Throughput Protein Similarity Searches in the LIBI Grid Problem Solving Environment

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    Bioinformatics applications are naturally distributed, due to distribution of involved data sets, experimental data and biological databases. They require high computing power, owing to the large size of data sets and the complexity of basic computations, may access heterogeneous data, where heterogeneity is in data format, access policy, distribution, etc., and require a secure infrastructure, because they could access private data owned by different organizations. The Problem Solving Environment (PSE) is an approach and a technology that can fulfil such bioinformatics requirements. The PSE can be used for the definition and composition of complex applications, hiding programming and configuration details to the user that can concentrate only on the specific problem. Moreover, Grids can be used for building geographically distributed collaborative problem solving environments and Grid aware PSEs can search and use dispersed high performance computing, networking, and data resources. In this work, the PSE solution has been chosen as the integration platform of bioinformatics tools and data sources. In particular an experiment of multiple sequence alignment on large scale, supported by the LIBIPSE, is presented

    Thermal and Mechanical Characterization of Yarn Samples from Flemish Tapestry of the Sixteenth Century

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    We propose a physico-chemical approach for theharacterization of the conservation condition of yarns from a Flemish tapestry of the sixteenth century. The aging effect on the yarns' performance was evaluated by comparison with commercial materials. Water uptake experiments highlighted the aptitude of yarns toward water sorption and their increased hydrophilicity upon aging. Thermogravimetric analysis can be considered a fast approach for the fiber identification and assessment on the material life-time. The dynamic mechanical analysis provided direct evidence on the yarns, conservation state and their performance under different mechanical stresses. The proposed characterization path can be relevant for stating the condition of the tapestry and for designing a conservation protocol for the preservation of the artwork

    Search for top-squark pair production in final states with one lepton, jets, and missing transverse momentum using 36 fb−1of sqrt(s) = 13 TeV pp collision data with the ATLAS detector

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    The results of a search for the direct pair production of top squarks, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, several energetic jets, and missing transverse momentum are reported. The analysis also targets spin-0 mediator models, where the mediator decays into a pair of dark-matter particles and is produced in association with a pair of top quarks. The search uses data from proton-proton collisions delivered by the Large Hadron Collider in 2015 and 2016 at a centre-of-mass energy of sqrt(s) = 13 TeV and recorded by the ATLAS detector, corresponding to an integrated luminosity of 36 fb−1. A wide range of signal scenarios with different mass-splittings between the top squark, the lightest neutralino and possible intermediate supersymmetric particles are considered, including cases where the W bosons or the top quarks produced in the decay chain are off-shell. No significant excess over the Standard Model prediction is observed. The null results are used to set exclusion limits at 95% confidence level in several supersymmetry benchmark models. For pair-produced top-squarks decaying into top quarks, top-squark masses up to 940 GeV are excluded. Stringent exclusion limits are also derived for all other considered top-squark decay scenarios. For the spin-0 mediator models, upper limits are set on the visible cross-section

    Search for Higgs boson decays to beyond-the-Standard-Model light bosons in four-lepton events with the ATLAS detector at sqrt(s) = 13 TeV

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    A search is conducted for a beyond-the-Standard-Model boson using events where a Higgs boson with mass 125 GeV decays to four leptons (ℓ = e or μ). This decay is presumed to occur via an intermediate state which contains one or two on-shell, promptly decaying bosons: H → ZX/XX → 4ℓ, where X is a new vector boson Zd or pseudoscalar a with mass between 1 and 60 GeV. The search uses pp collision data collected with the ATLAS detector at the LHC with an integrated luminosity of 36.1 fb−1 at a centre-of-mass energy sqrt(s) = 13 TeV. No significant excess of events above Standard Model background predictions is observed; therefore, upper limits at 95% confidence level are set on modelindependent fiducial cross-sections, and on the Higgs boson decay branching ratios to vector and pseudoscalar bosons in two benchmark models

    Measurement of the cross section for isolated-photon plus jet production in pp collisions at sqrt(s) = 13TeV using the ATLAS detector

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    The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
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