1,366 research outputs found

    A new data analysis framework for the search of continuous gravitational wave signals

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    Continuous gravitational wave signals, like those expected by asymmetric spinning neutron stars, are among the most promising targets for LIGO and Virgo detectors. The development of fast and robust data analysis methods is crucial to increase the chances of a detection. We have developed a new and flexible general data analysis framework for the search of this kind of signals, which allows to reduce the computational cost of the analysis by about two orders of magnitude with respect to current procedures. This can correspond, at fixed computing cost, to a sensitivity gain of up to 10%-20%, depending on the search parameter space. Some possible applications are discussed, with a particular focus on a directed search for sources in the Galactic center. Validation through the injection of artificial signals in the data of Advanced LIGO first observational science run is also shown.Comment: 21 pages, 8 figure

    An improved algorithm for narrow-band searches of continuous gravitational waves

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    Continuous gravitational waves signals, emitted by asymmetric spinning neutron stars, are among the main targets of current detectors like Advanced LIGO and Virgo. In the case of sources, like pulsars, which rotational parameters are measured through electromagnetic observations, typical searches assume that the gravitational wave frequency is at a given known fixed ratio with respect to the star rotational frequency. For instance, for a neutron star rotating around one of its principal axis of inertia the gravitational signal frequency would be exactly two times the rotational frequency of the star. It is possible, however, that this assumption is wrong. This is why search algorithms able to take into account a possible small mismatch between the gravitational waves frequency and the frequency inferred from electromagnetic observations have been developed. In this paper we present an improved pipeline to perform such narrow-band searches for continuous gravitational waves from neutron stars, about three orders of magnitude faster than previous implementations. The algorithm that we have developed is based on the {\it 5-vectors} framework and is able to perform a fully coherent search over a frequency band of width O\mathcal{O}(Hertz) and for hundreds of spin-down values running a few hours on a standard workstation. This new algorithm opens the possibility of long coherence time searches for objects which rotational parameters are highly uncertain.Comment: 19 pages, 8 figures, 6 tables, submitted to CQ

    A semi-coherent analysis method to search for continuous gravitational waves emitted by ultra-light boson clouds around spinning black holes

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    As a consequence of superradiant instability induced in Kerr black holes, ultra-light boson clouds can be a source of persistent gravitational waves, potentially detectable by current and future gravitational-wave detectors. These signals have been predicted to be nearly monochromatic, with a small steady frequency increase (spin-up), but given the several assumptions and simplifications done at theoretical level, it is wise to consider, from the data analysis point of view, a broader class of gravitational signals in which the phase (or the frequency) slightly wander in time. Also other types of sources, e.g. neutron stars in which a torque balance equilibrium exists between matter accretion and emission of persistent gravitational waves, would fit in this category. In this paper we present a robust and computationally cheap analysis pipeline devoted to the search of such kind of signals. We provide a full characterization of the method, through both a theoretical sensitivity estimation and through the analysis of syntethic data in which simulated signals have been injected. The search setup for both all-sky searches and higher sensitivity directed searches is discussed.Comment: 13 pages, 13 figure

    Evaluation of toxic chemical parameters and ecotoxicity levels in bottled mineral waters

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    Heavy metals, phthalates, characterizing elements, CO2 concentrations and pH and hardness levels were measured in forty samples of bottled mineral waters. In some samples arsenic, manganese, mercury and selenium were present in higher concentrations than permitted by Italian law. No significant release of phthalates from containers in PET was observed. In the same samples, toxicity tests with Daphnia magna were carried out. Toxicity levels, expressed as % of immobile organisms, ranged from 0 to 100%; generally the highest toxicity values were found in the hardwaters

    Hepatic PPARs: their role in liver physiology, fibrosis and treatment

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    Complex molecular and cellular mechanisms are involved in the pathway of liver fibrosis. Activation and transformation of hepatic stellate cells (HSCs) are considered the two main reasons for the cause and development of liver fibrosis. The peroxisome proliferator-activated receptors (PPARs) belonging to the family of ligand-activated transcription factors play a key role in liver homeostasis, regulating adipogenesis and inhibiting fibrogenesis in HSCs. Normal transcriptional function of PPARs contributes to maintain HSCs in quiescent phase. A reduced expression of PPARs in HSCs greatly induces a progression of liver fibrosis and an increased production of collagen. Here, we discuss role and function of PPARs and we take into consideration molecular factors able to reduce PPARs activity in HSCs. Finally, although further validations are needed, we illustrate novel strategies available from in vitro and animal studies on how some PPARs-agonists have been proved effective as antifibrotic substances in liver disease

    Build-Up/Wash-Off Monitoring and Assessment for Sustainable Management of First Flush in an Urban Area

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    The characterization of stormwater runoff on urbanized surfaces by means of comparison between experimental data and simulations is a strict requirement for a sustainable management of urban sewer systems. A monitoring campaign was carried out within a residential area in Puglia (Southern Italy) in order to collect and evaluate quantity and quality data. A strong correlation was observed between COD (Chemical Oxygen Demand) and TSS (Total Suspended Solid) concentrations, whose values exceed water quality standards. TSS was used for calibration of Storm Water Management Model (SWMM) which was then validated with reference to the pollutograph’s shape and the peak-time. The first flush phenomenon occurrence was also investigated by looking at the distribution of pollutant mass vs. volume in stormwater discharges, using the so-called “M(V) curves”. Results show that on average the first 30% of that washed off carries 60% of TSS and provides important information for the design of efficient systems for first flush treatment

    Epigallocatechin-3-gallate inhibits doxorubicin-induced inflammation on human ovarian tissue

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    Chemotherapy protocol can destroy the reproductive potential of young cancer patients. Doxorubicin (DOX) is a potent anthracycline commonly used in the treatment of numerous malignancies. The purpose of the study was to evaluate the ovarian toxicity of DOX via inflammation and the possible protective effect of the green tea polyphenol epigallocatechin-3-gallate (EGCG). Ovarian tissue of three patients was cultured with 1 \ub5g/ml DOX and/or 10 \ub5g/ml EGCG for 24 and 48 h. Levels of inflammatory factors were determined by quantitative Real-Time PCR, western blot, zimography, and multiplex bead-based immunoassay. Morphological evaluation, damaged follicle count and TUNEL assay were also performed. DOX influenced inflammatory responses by inducing a significant increase in the expression of pro-inflammatory cytokines, such as tumor necrosis factor-\u3b1 (TNF-\u3b1) and cyclooxigenase-2 (COX-2), of inflammatory interleukins (IL), such as interleukin-6 (IL-6) and interleukin-8 (IL-8), and the inflammatory proteins mediators metalloproteinase-2 and metalloproteinase-9 (MMP2 and MMP9). IL-8 secretion in the culture supernatants and MMP9 activity also significantly raised after DOX treatment. Moreover, a histological evaluation of the ovarian tissue showed morphological damage to follicles and stroma after DOX exposure. EGCG significantly reduced DOX-induced inflammatory responses and improved the preservation of follicles. DOX-induced inflammation could be responsible for the ovarian function impairment of chemotherapy. EGCG could have a protective role in reducing DOX-mediated inflammatory responses in human ovarian tissue

    PO-485 Low abundance circulating proteins in giant cell tumours of bone

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    Introduction Circulating low-abundance proteins/fragments generating from tumour cells and tissues, represent the most important source of cancer biomarkers useful for early diagnosis and prognosis. Giant cell tumour of bone (GCT) is a benign neoplasm occurring in the long bone and in the axial skeleton of young adults. Approximately 5% of GCT develop pulmonary metastases. Although many biomarkers have been proposed, identification of circulating low abundance molecules may be useful to predict metastasis with a non invasive method. Material and methods The hydrogel nanoparticles technique followed by mass spectrometry was used to detect low molecular weight serum proteins or protein fragments in serum of 20 GCT patients with different clinical course and in 10 healthy sera used as control. The most representative low-abundant de novo or differentially abundant proteins were submitted to String database in order to define protein-protein interaction network. Cluster analysis was performed to identify prognostic groups of patients with similar abundance of proteins that significantly discriminate between the groups. Results and discussions For the 25 low-abundant de novo or differentially abundant proteins identified, we recognised that the top interconnected pathways included protein activation cascade, wound healing, blood coagulation, cell-substrate adhesion. Proteoma cluster analysis separated metastasis-free from metastatic GCT patients in two well-defined groups where serum levels of signalling transduction mediators and regulators of kinase activity presented a high discriminatory power. Increased expression of proteins STAT5B, GRB2 and OXSR1 was related to a higher probability of metastasis. Conclusion In conclusion, using a no invasive technique, we identified differentially abundant serum biomarkers, also providing prognostic information in patients with GCT of bone. Future studies are ongoing to establish the interplay between these biomarkers in order to fully understand the mechanism involved in tumour development and to focus on the planning of tailored therapies that should be more effective and less toxic

    A real-world study on unmet medical needs in triptan-treated migraine: Prevalence, preventive therapies and triptan use modification from a large Italian population along two years

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    Although migraine is a disabling neurological condition that causes important disability, it remains an area of underdiagnosis and undertreatment worldwide. The aim of this study was to depict the burden of the unmet medical needs in migraine treated with triptans in a large Italian population

    Pur-alpha functionally interacts with FUS carrying ALS-associated mutations

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    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder due to motor neuron loss. Fused in sarcoma (FUS) protein carrying ALS-associated mutations localizes to stress granules and causes their coalescence into larger aggregates. Here we show that Pur-alpha physically interacts with mutated FUS in an RNA-dependent manner. Pur-alpha colocalizes with FUS carrying mutations in stress granules of motoneuronal cells differentiated from induced pluripotent stem cells and that are derived from ALS patients. We observe that both Pur-alpha and mutated FUS upregulate phosphorylation of the translation initiation factor eukaryotic translation initiation factor 2 alpha and consistently inhibit global protein synthesis. In vivo expression of Pur-alpha in different Drosophila tissues significatively exacerbates the neurodegeneration caused by mutated FUS. Conversely, the downregulation of Pur-alpha in neurons expressing mutated FUS significatively improves fly climbing activity. All these findings suggest that Pur-alpha, through the control of mRNA translation, might be involved in the pathogenesis of ALS associated with the mutation of FUS, and that an alteration of protein synthesis may be directly implicated in the disease. Finally, in vivo RNAi-mediated ablation of Pur-alpha produced locomotion defects in Drosophila, indicating a pivotal role for this protein in the motoneuronal function
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