1,107 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

    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

    Testbed for the Pellet Launching System for JT-60SA

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    As part of the European contribution to the large size superconducting tokamak project JT-60SA, a new Pellet Launching System (PLS) is designed and built. The aims of the PLS are to provide efficient fuelling to the plasma and to control and mitigate Edge Localised Modes (ELMs). Two pellet sources, one for fuelling pellets, one for pacing pellets, are delivering pellets to a centrifuge launcher. The centrifuge enables precise launch of pellets according to already proven control schemes. Furthermore, this system opens a way towards a test bed for the EU-DEMO fuelling system. The new PLS has to be completed and commissioned first at the IPP Garching pellet lab and then to be shipped to QST Naka site after having demonstrated its performance. This dedicated test bed has been set up, providing suitable vacuum conditions to operate the PLS in similar conditions (except magnetic field and radiation). Maximum hydrogen throughput is about 400 mbar·L/s per pellet source. Safety issues must be considered for hydrogen inventory of pellet sources (∼100 bar·L each). In a first step, the pellet sources will be put on a test vessel providing inherent safety by a huge volume (10 m³) which makes sure that the hydrogen concentration is below 1% under all circumstances. A hydrogen safety survey prior to assembly confirmed the concept to be followed by an assessment after the installation in order to get the required license for operation. The PLS as a whole, for the time being equipped with two pellet sources, is to be certified according to explosion prevention rules (ATEX) as a product to be shipped to Naka site. To obtain this, an appropriate declaration of explosion zones inside the vacuum system and the use of suitable and certified equipment is mandatory. Such, the integration of this system can be planned and assessed on a clear technical and regulatory basis

    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

    EM-100 Precision Irrigators Network

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    Identifying best management practices (BMPs) promoting greater water use efficiency while maintaining crop yields is essential to the future of Texas cropping systems. Available water for irrigated crops is vital for sustaining crop production throughout the state. However, the availability of this water for irrigation is diminishing through competition by urban development and, in some regions such as the Edwards Aquifer, is falling under state regulation. The awareness and improvement of efficient irrigation and best management practices to conserve water while maintaining crop production will help preserve the aquifer levels and increase water savings to producers. One component of BMPs for conserving water use is the application of decision support systems (DSS) that are used as tools for implementing irrigation BMPs. This DSS guide was developed as a complement to TWDB Report 362, "Water Conservation Best Management Practices Guide," which is a more comprehensive report on water conservation including an "Agricultural Irrigation Water Use Management" BMPs section. The full TWDB Report 362 can be found at: http://www.twdb.state.tx.us/assistance/conservation/consindex.asp. DSS include the Texas High Plains Evapotranspiration Network (TXHPET), the Precision Irrigators Network (PIN) and the Crop Production Management (CroPMan) model. These DSS strive to promote grower awareness of water conservation strategies. Irrigation conservation strategies are proposed to result in savings of approximately 1.4 million acre-feet per year by 2060 (TWDB and TWRI). TXHPET operates 18 meteorological stations located in 15 counties across the Texas North Plains and Texas South Plains. The regional coverage of TXHPET is estimated at 4 million irrigated acres. The network offers insight to evapotranspiration (ET)-based crop water use that producers and agricultural consultants can reference when making decisions on when and how much to irrigate their crops. This information is available to data users via fax or online (http://txhighplainset.tamu.edu) and currently results in approximately 300,000 downloads or faxes annually. The PIN program was formed in 2004 with a goal of saving millions of gallons of water annually by reducing irrigation water use by as much as 20 percent over several years and currently supports several crops (corn, cotton, sorghum, wheat) in seven counties of South Central Texas. Cooperation of the PIN programs consists of area producers, Texas Agricultural Experiment Station researchers, Texas Cooperative Extension personnel, San Antonio Water System, Edwards Aquifer Authority, Texas Water Resources Institute, Texas Water Development Board, Uvalde County Underground Water Conservation District and Wintergarden Water Conservation District. The PIN database will allow producers to gain historical and real-time information for better management of irrigation scheduling. The PIN program estimates that when all irrigators in the Edwards Aquifer region implement limited irrigation scheduling, approximately 50,000 to 60,000 acre-feet of water can be saved per year and made available for purposes other than agriculture. CroPMan is a computer model designed to aid producers and agricultural consultants in optimizing crop management and maximizing production and profit through a production-risk approach. CroPMan will help growers identify limitations to crop yield, assist in making replant decisions and help recognize management practices that reduce the impact of agriculture on soil erosion and water quality. CroPMan is a Windows-based application program that can be downloaded from the CroPMan Web site (http://cropman.brc.tamus.edu)

    Assessing the Association of Pioglitazone Use and Bladder Cancer Through Drug Adverse Event Reporting

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    OBJECTIVE\u2014To analyze the association between pioglitazone use and bladder cancer through a spontaneous adverse event reporting system for medications. RESEARCH DESIGN AND METHODS\u2014Case/noncase bladder cancer reports associated with antidiabetic drug use were retrieved from the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) between 2004 and 2009 and analyzed by the reporting odds ratio (ROR). RESULTS\u2014Ninety-three reports of bladder cancer were retrieved, corresponding to 138 drug reaction pairs (pioglitazone, 31; insulin, 29; metformin, 25; glimepiride, 13; exenatide, 8; others, 22). RORwas indicative of a definite risk for pioglitazone (4.30 [95%CI 2.82\u20136.52]), and a much weaker risk for gliclazide and acarbose, with very few cases being treated with these two drugs (6 and 4, respectively). CONCLUSIONS\u2014In agreement with preclinical and clinical studies, AERS analysis is consistent with an association between pioglitazone and bladder cancer. This issue needs constant epidemiologic surveillance and urgent definition by more specific studies

    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

    Macrophage MerTK promotes profibrogenic cross-talk with hepatic stellate cells via soluble mediators

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    Background & Aims: Activation of Kupffer cells and recruitment of monocytes are key events in fibrogenesis. These cells release soluble mediators which induce the activation of hepatic stellate cells (HSCs), the main fibrogenic cell type within the liver. Mer tyrosine kinase (MerTK) signaling regulates multiple processes in macrophages and has been implicated in the pathogenesis of non-alcoholic steatohepatitis-related fibrosis. In this study, we explored if MerTK activation in macrophages influences the profibrogenic phenotype of HSCs. Methods: Macrophages were derived from THP-1 cells or differentiated from peripheral blood monocytes towards MerTK+/CD206+/CD163+/CD209- macrophages. The role of MerTK was assessed by pharmacologic and genetic inhibition. HSC migration was determined in Boyden chambers, viability was measured by the MTT assay, and proliferation was evaluated by the BrdU incorporation assay. Results: Gas-6 induced MerTK phosphorylation and Akt activation in macrophages, and these effects were inhibited by UNC569. During polarization, MerTK+/CD206+/CD163+/CD209- macrophages exhibited activation of STAT3, ERK1/2, p38 and increased expression of VEGF-A. Activation of MerTK in THP-1 macrophages induced a secretome which promoted a significant increase in migration, proliferation, viability and expression of profibrogenic factors in HSCs. Similarly, conditioned medium from MerTK+ macrophages induced a significant increase in cell migration, proliferation, STAT3 and p38 phosphorylation and upregulation of IL-8 expression in HSCs. Moreover, conditioned medium from Gas-6-stimulated Kupffer cells induced a significant increase in HSC proliferation. These effects were specifically related to MerTK expression and activity in macrophages, as indicated by pharmacologic inhibition and knockdown experiments. Conclusions: MerTK activation in macrophages modifies the secretome to promote profibrogenic features in HSCs, implicating this receptor in the pathogenesis of hepatic fibrosis. Lay summary: Fibrosis represents the process of scarring occurring in patients with chronic liver diseases. This process depends on production of scar tissue components by a specific cell type, named hepatic stellate cells, and is regulated by interaction with other cells. Herein, we show that activation of MerTK, a receptor present in a population of macrophages, causes the production of factors that act on hepatic stellate cells, increasing their ability to produce scar tissue
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