214 research outputs found

    Evaluation of bioactivity of fucoidan from laminaria with in vitro human cell cultures (THP-1)

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesBackground: Seaweeds represent one of the few remaining food sources available globally which are not being fully utilized or even over utilized. Kelps (Laminaria spp.) are one of the numerous species of brown seaweeds, a popular marine vegetable, which has been used as a source of iodine and minerals for centuries. Kelps contain anionic polysaccharides called fucoidans heteroglycans with L-fucose units. Their monosaccharide composition, physicochemical and bioactive properties vary between seaweed species. The objective of this work was to evaluate the bioactive properties of laminaria fucoidan (L. digitata and L. hyperborea) toward THP-1 macrophages, a human macrophage like cell line, and investigate its potential antioxidant and immunomodulatory characteristics. Methods: THP-1 macrophages were incubated with five fucoidan concentrations. The Oxygen Radical Absorbance Capacity (ORAC) assay was determined for cell lysates and for the fucoidan extract, in addition to Total Polyphenol Content (TPC). Cytotoxicity of fucoidan was assessed by light microscopy, followed by XTT proliferation assay. Enzyme-linked immunosorbant assays (ELISA) were performed to determine concentrations of the secreted tumor necrosis factor a (TNF-a), interleukin 6 (IL-6), and interleukin 10 (IL-10). Results: Fucoidan did not affect macrophage ability to scavenge oxygen radicals (ORAC) confirming its antioxidant properties toward activated macrophages. The laminaria fucoidan extract at 100 mu g/ml concentration lowered macrophage viability. Lower concentrations of laminaria fucoidan did not have impact on cell viability. Very low concentration of fucoidan at 0.1 mu g/ml triggered secretion of TNF-alpha. However, IL-6 and interleukin IL-10 were expressed when concentration of applied fucoidan was 10 mu g/ml indicating bioactivity of laminaria fucoidan through immunomodulatory actions. Conclusions: The study demonstrated how laminaria fucoidan may have bioactive properties towards THP-1 macrophages. Changes in cytokine secretion between pro-inflammatory (TNF-alpha, and IL-6) and anti-inflammatory (IL-10) cytokines confirmed bioactivity of the laminaria fucoidan extracts.University of Iceland Research Fun

    Simulating ecosystem adaptation in response to a changing climate by capturing belowground plant functional traits in an eco-evolutionary vegetation model (Plant-FATE)

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    In the face of ongoing global crises, such as climate change and biodiversity loss, we urgently need to understand the dynamic and complex adaptive responses of global forest ecosystems. To do so, we need to develop modelling frameworks that account for multiple temporal and organizational scales, and therefore capture functional adaptations of individuals, species, and ecosystems in response to the environment. Here we present Plant-FATE (Plant Functional Acclimation and Trait Evolution) an eco-evolutionary vegetation model that embodies functional diversity by representing plant life-history strategies in trait space, and adaptations by accounting for short-term physiological acclimation, mid-term demographic shifts, and long-term trait evolution. Tested with data obtained from an hyperdiverse site in the Amazon Forest, our model captures plant functional characteristics and therefore correctly predicts emergent ecosystem properties, such as the size distribution and community-composition of the local species pool. As a next step, we are extending the physiological module of Plant-FATE by implementing an optimality-based representation of belowground plant traits that captures the observed trade-offs between water/nutrient uptake and the requisite investment into fine root biomass. At the community level, this means that changes in soil fertility or water content, e.g. during drought, can alter belowground strategies of plants competing for limiting resources. By incorporating a dynamic representation of belowground plant functional traits and capturing the eco-evolutionary niches of plant species coexisting across natural environmental gradients, we are able to represent ecosystem adaptation and community shifts in response to a changing climate and therefore will be able to simulate the functional response of forest ecosystems under future scenarios

    Confronting experimental data with heavy-ion models: Rivet for heavy ions

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    The Rivet library is an important toolkit in particle physics, and serves as a repository for analysis data and code. It allows for comparisons between data and theoretical calculations of the final state of collision events. This paper outlines several recent additions and improvements to the framework to include support for analysis of heavy ion collision simulated data. The paper also presents examples of these recent developments and their applicability in implementing concrete physics analyses

    Physics at the e+ e- Linear Collider

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    A comprehensive review of physics at an e+e- Linear Collider in the energy range of sqrt{s}=92 GeV--3 TeV is presented in view of recent and expected LHC results, experiments from low energy as well as astroparticle physics.The report focuses in particular on Higgs boson, Top quark and electroweak precision physics, but also discusses several models of beyond the Standard Model physics such as Supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analyzed as well.Comment: 179 pages, plots and references updated, version to be published at EPJ

    Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton

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    According to the CPT theorem, which states that the combined operation of charge conjugation, parity transformation and time reversal must be conserved, particles and their antiparticles should have the same mass and lifetime but opposite charge and magnetic moment. Here, we test CPT symmetry in a nucleus containing a strange quark, more specifically in the hypertriton. This hypernucleus is the lightest one yet discovered and consists of a proton, a neutron, and a Λ\Lambda hyperon. With data recorded by the STAR detector{\cite{TPC,HFT,TOF}} at the Relativistic Heavy Ion Collider, we measure the Λ\Lambda hyperon binding energy BΛB_{\Lambda} for the hypertriton, and find that it differs from the widely used value{\cite{B_1973}} and from predictions{\cite{2019_weak, 1995_weak, 2002_weak, 2014_weak}}, where the hypertriton is treated as a weakly bound system. Our results place stringent constraints on the hyperon-nucleon interaction{\cite{Hammer2002, STAR-antiH3L}}, and have implications for understanding neutron star interiors, where strange matter may be present{\cite{Chatterjee2016}}. A precise comparison of the masses of the hypertriton and the antihypertriton allows us to test CPT symmetry in a nucleus with strangeness for the first time, and we observe no deviation from the expected exact symmetry
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