109 research outputs found

    Tissue-Specific Biomarker Responses in the Blue Mussel Mytilus spp. Exposed to a Mixture of Microplastics at Environmentally Relevant Concentrations

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    The impact of a microplastic (MP) mixture composed of polyethylene (PE) and polypropylene (PP) plastic particles, prepared from commercially available products, was evaluated in blue mussels Mytilus spp. exposed to three environmentally relevant concentrations: 0.008 ÎŒg L−1 (low), 10 ÎŒg L−1 (medium), and 100 ÎŒg L−1 (high). Organisms were exposed for 10 days followed by 10 days of depuration in clean seawater under controlled laboratory conditions. The evaluation of MP effects on mussel clearance rate, tissue structure, antioxidant defenses, immune and digestive parameters, and DNA integrity were investigated while the identification of plastic particles in mussel tissues (gills, digestive gland, and remaining tissues), and biodeposits (feces and pseudofaeces) was performed using infrared microscopy (ÎŒFT-IR). Results showed the presence of MPs only in the digestive gland of mussels exposed to the highest tested concentration of MPs with a mean of 0.75 particle/mussel (after the 10 days of exposure). In biodeposits, PE and PP particles were detected following exposure to all tested concentrations confirming the ingestion of MPs by the organisms. A differential response of antioxidant enzyme activities between digestive gland and gills was observed. Significant increases in superoxide dismutase (SOD) and catalase (CAT) activities were measured in the digestive gland of mussels exposed to the low (0.008 ÎŒg L−1) and medium (10 ÎŒg L−1) concentrations of MPs and in the gills from mussels exposed to the highest concentration (100 ÎŒg L−1) of MPs that could be indicative of a change in the redox balance. Moreover, an increase in acid phosphatase activity was measured in hemolymph of mussels exposed to 0.008 and 10 ÎŒg L−1 concentrations. No significant difference was observed in the clearance rate, and histopathological parameters between control and exposed mussels. This study brings new insights on the potential sublethal impacts of MPs at environmentally relevant concentrations in marine bivalves

    Consecuencias econĂłmicas de la prohibiciĂłn del PlĂĄstico en Colombia

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    Trabajo de InvestigaciĂłnEl plĂĄstico es un material orgĂĄnico y que durante su fabricaciĂłn son muchos los usos para obtener diferentes formas, ademĂĄs de su utilizaciĂłn econĂłmica para la industria y su bajo costo de fabricaciĂłn, es inevitable no estar rodeados de artĂ­culos hechos a base de este componente. Sin embargo, el plĂĄstico se ha convertido en un problema que con el pasar de los dĂ­as se va creciendo, dado que se encuentra en casi todos los productos que utilizamos a diario, ya sea en consumo personal o en las actividades y hasta en los alimentos. La producciĂłn y consumo de plĂĄsticos en el mundo durante los Ășltimos años ha aumentado de forma acelerada, alcanzando cifras alarmantes y cuya consecuencia principal es la contaminaciĂłn del entorno y el medio ambiente, poniendo en peligro las especies que habitan los ecosistemas del planeta, principalmente los ocĂ©anos, mares y rĂ­os; razĂłn por la cual se es necesario empezar a revisar este tema y asĂ­ tomar las diferentes decisiones que permitan dar una soluciĂłn de fondo y asĂ­ reducir el consumo, apoyĂĄndose en programas para la reutilizaciĂłn y el reciclaje de desechos impulsados por el Estado y la poblaciĂłn en general.1. CapĂ­tulo 1: IntroducciĂłn 2. CapĂ­tulo 2: Marco de Referencia 3. Resultados y DiscusiĂłn de resultados 4. Conclusiones 5. ReferenciasPregradoEconomist

    The need for harmonization and innovation of neuropsychological assessment in neurodegenerative dementias in Europe: consensus document of the Joint Program for Neurodegenerative Diseases Working Group

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    Cognitive, behavioural, and functional assessment is crucial in longitudinal studies of neurodegenerative dementias (NDD). Central issues, such as the definition of the study population (asymptomatic, at risk, or individuals with dementia), the detection of change/decline, and the assessment of relevant outcomes depend on quantitative measures of cognitive, behavioural, and functional status. Currently, we are far from having available reliable protocols and tools for the assessment of dementias in Europe. The main problems are the heterogeneity of the tools used across different European countries, the lack of standardisation of administration and scoring methods across centres, and the limited information available about the psychometric properties of many tests currently in widespread use. This situation makes it hard to compare results across studies carried out in different centres, thus hampering research progress, in particular towards the contribution to a “big data” common data set. We present here the results of a project funded by the Joint Program for Neurodegenerative Diseases (JPND) and by the Italian Ministry of Health. The project aimed at providing a consensus framework for the harmonisation of assessment tools to be applied to research in neurodegenerative disorders affecting cognition across Europe. A panel of European experts reviewed the current methods of neuropsychological assessment, identified pending issues, and made recommendations for the harmonisation of neuropsychological assessment of neurodegenerative dementias in Europe. A consensus was achieved on the general recommendations to be followed in developing procedures and tools for neuropsychological assessment, with the aim of harmonising tools and procedures to achieve more reliable data on the cognitive-behavioural examination. The results of this study should be considered as a first step to enhancing a common view and practise on NDD assessment across European countries

    Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at root s=7 and 8 TeV

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    70 pages plus author lists + cover page (104 pages total), 32 figures, 22 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2015-07/ and at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-15-002/Combined ATLAS and CMS measurements of the Higgs boson production and decay rates, as well as constraints on its couplings to vector bosons and fermions, are presented. The combination is based on the analysis of five production processes, namely gluon fusion, vector boson fusion, and associated production with a WW or a ZZ boson or a pair of top quarks, and of the six decay modes H→ZZ,WWH \to ZZ, WW, γγ,ττ,bb\gamma\gamma, \tau\tau, bb, and ΌΌ\mu\mu. All results are reported assuming a value of 125.09 GeV for the Higgs boson mass, the result of the combined measurement by the ATLAS and CMS experiments. The analysis uses the CERN LHC proton--proton collision data recorded by the ATLAS and CMS experiments in 2011 and 2012, corresponding to integrated luminosities per experiment of approximately 5 fb−1^{-1} at s=7\sqrt{s}=7 TeV and 20 fb−1^{-1} at s=8\sqrt{s} = 8 TeV. The Higgs boson production and decay rates measured by the two experiments are combined within the context of three generic parameterisations: two based on cross sections and branching fractions, and one on ratios of coupling modifiers. Several interpretations of the measurements with more model-dependent parameterisations are also given. The combined signal yield relative to the Standard Model prediction is measured to be 1.09 ±\pm 0.11. The combined measurements lead to observed significances for the vector boson fusion production process and for the H→ττH \to \tau\tau decay of 5.45.4 and 5.55.5 standard deviations, respectively. The data are consistent with the Standard Model predictions for all parameterisations considered.Peer reviewe

    A new way to discriminate polluted wood by vibrational spectroscopies

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    Current methods to monitor microalgae-nanoparticle interaction and associated effects

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    International audienceWidespread use of nanoparticles for different applications has diffused their presence in the environment, particularly in water. Many studies have been conducted to evaluate their effects on aquatic organisms. Microalgae are at the base of aquatic trophic chains. These organisms which can be benthic or pelagic, meaning that they can enter into interaction with all kinds of particulate materials whatever their density, and constitute an interesting model study. The purpose of this review was to gather more than sixty studies on microalgae exposure to the different nanoparticles that may be present in the aquatic environment. After a brief description of each type of nanoparticle (metals, silica and plastic) commonly used in ecotoxicological studies, techniques to monitor their properties are presented. Then, different effects on microalgae resulting from interaction with nanoparticles are described as well as the parameters and techniques for monitoring them. The impacts described in the literature are primarily shading, ions release, oxidative stress, adsorption, absorption and disruption of microalgae barriers. Several parameters are proposed to monitor effects such as growth, photosynthesis, membrane integrity, biochemical composition variations and gene expression changes. Finally, in the literature, while different impacts of nanoparticles on microalgae have been described, there is no consensus on evidence of nanomaterial toxicity with regard to microalgae. A parallel comparison of different nanoparticle types appears essential in order to prioritize which factors exert the most influence on toxicity in microalgae cultures: size, nature, surface chemistry, concentration or interaction time

    Interactions between polystyrene nanoparticles and Chlamydomonas reinhardtii monitored by infrared spectroscopy combined with molecular biology

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    International audienceFor several decades, use of nanoparticles (NP) on a global scale has been generating new potential sources of organism disruption. Recent studies have shown that NP can cause modifications on the biochemical macromolecular composition of microalgae and raised questions on the toxicity of plastic particles, which are widespread in the aquatic environment. Polystyrene (PS) particles are among the most widely used plastics in the world. In our experimentation, a combined approach of infrared spectroscopy and molecular biology (real-time PCR) has been applied in order to better apprehend the consequences of interactions between Chlamydomonas reinhardtii, freshwater microalgae and PS NP. Two references have been used, nitrogen deprivation -a well-documented stressor-, and gold nanoparticles (Au-NP). As regards biochemical composition, our experiments show a differing microalga response, according to the NP to which they have been exposed. Results with infrared spectroscopy and gene expression methods are consistent and illustrate variation among several carbohydrates (galactose
). Furthermore, PS-NP seem to react in the same direction as nitrogen limitation, thereby supporting the hypothesis that PS-NP can induce response mechanisms to environmental changes in microalgae. This study highlighted the interest of combining infrared spectroscopy and gene expression as means of monitoring microalgae response to nanoplastics
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