590 research outputs found

    Transverse Dynamics and Energy Tuning of Fast Electrons Generated in Sub-Relativistic Intensity Laser Pulse Interaction with Plasmas

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    The regimes of quasi-mono-energetic electron beam generation were experimentally studied in the sub-relativistic intensity laser plasma interaction. The observed electron acceleration regime is unfolded with two-dimensional-particle-in-cell simulations of laser-wakefield generation in the self-modulation regime.Comment: 10 pages, 5 figure

    IRF-5-dependent signaling restricts Orthobunyavirus dissemination to the central nervous system

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    ABSTRACT Interferon (IFN)-regulatory factor 5 (IRF-5) is a transcription factor that induces inflammatory responses after engagement and signaling by pattern recognition receptors. To define the role of IRF-5 during bunyavirus infection, we evaluated Oropouche virus (OROV) and La Crosse virus (LACV) pathogenesis and immune responses in primary cells and in mice with gene deletions in Irf3 , Irf5 , and Irf7 or in Irf5 alone. Deletion of Irf3 , Irf5 , and Irf7 together resulted in uncontrolled viral replication in the liver and spleen, hypercytokinemia, extensive liver injury, and an early-death phenotype. Remarkably, deletion of Irf5 alone resulted in meningoencephalitis and death on a more protracted timeline, 1 to 2 weeks after initial OROV or LACV infection. The clinical signs in OROV-infected Irf5 −/− mice were associated with abundant viral antigen and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells in several regions of the brain. Circulating dendritic cell (DC) subsets in Irf5 −/− mice had higher levels of OROV RNA in vivo yet produced lower levels of type I IFN than wild-type (WT) cells. This result was supported by data obtained in vitro , since a deficiency of IRF-5 resulted in enhanced OROV infection and diminished type I IFN production in bone marrow-derived DCs. Collectively, these results indicate a key role for IRF-5 in modulating the host antiviral response in peripheral organs that controls bunyavirus neuroinvasion in mice. IMPORTANCE Oropouche virus (OROV) and La Crosse virus (LACV) are orthobunyaviruses that are transmitted by insects and cause meningitis and encephalitis in subsets of individuals in the Americas. Recently, we demonstrated that components of the type I interferon (IFN) induction pathway, particularly the regulatory transcription factors IRF-3 and IRF-7, have key protective roles during OROV infection. However, the lethality in Irf3 −/− Irf7 −/− (DKO) mice infected with OROV was not as rapid or complete as observed in Ifnar −/− mice, indicating that other transcriptional factors associated with an IFN response contribute to antiviral immunity against OROV. Here, we evaluated bunyavirus replication, tissue tropism, and cytokine production in primary cells and mice lacking IRF-5. We demonstrate an important role for IRF-5 in preventing neuroinvasion and the ensuing encephalitis caused by OROV and LACV

    A High Luminosity e+e- Collider to study the Higgs Boson

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    A strong candidate for the Standard Model Scalar boson, H(126), has been discovered by the Large Hadron Collider (LHC) experiments. In order to study this fundamental particle with unprecedented precision, and to perform precision tests of the closure of the Standard Model, we investigate the possibilities offered by An e+e- storage ring collider. We use a design inspired by the B-factories, taking into account the performance achieved at LEP2, and imposing a synchrotron radiation power limit of 100 MW. At the most relevant centre-of-mass energy of 240 GeV, near-constant luminosities of 10^34 cm^{-2}s^{-1} are possible in up to four collision points for a ring of 27km circumference. The achievable luminosity increases with the bending radius, and for 80km circumference, a luminosity of 5 10^34 cm^{-2}s^{-1} in four collision points appears feasible. Beamstrahlung becomes relevant at these high luminosities, leading to a design requirement of large momentum acceptance both in the accelerating system and in the optics. The larger machine could reach the top quark threshold, would yield luminosities per interaction point of 10^36 cm^{-2}s^{-1} at the Z pole (91 GeV) and 2 10^35 cm^{-2}s^{-1} at the W pair production threshold (80 GeV per beam). The energy spread is reduced in the larger ring with respect to what is was at LEP, giving confidence that beam polarization for energy calibration purposes should be available up to the W pair threshold. The capabilities in term of physics performance are outlined.Comment: Submitted to the European Strategy Preparatory Group 01-04-2013 new version as re-submitted to PRSTA

    All-sky search of NAUTILUS data

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    A search for periodic gravitational-wave signals from isolated neutron stars in the NAUTILUS detector data is presented. We have analyzed half a year of data over the frequency band Hz,thespindownrange Hz, the spindown range Hz/s and over the entire sky. We have divided the data into 2 day stretches and we have analyzed each stretch coherently using matched filtering. We have imposed a low threshold for the optimal detection statistic to obtain a set of candidates that are further examined for coincidences among various data stretches. For some candidates we have also investigated the change of the signal-to-noise ratio when we increase the observation time from two to four days. Our analysis has not revealed any gravitational-wave signals. Therefore we have imposed upper limits on the dimensionless gravitational-wave amplitude over the parameter space that we have searched. Depending on frequency, our upper limit ranges from 3.4×10233.4 \times 10^{-23} to 1.3×10221.3 \times 10^{-22}. We have attempted a statistical verification of the hypotheses leading to our conclusions. We estimate that our upper limit is accurate to within 18%.Comment: LaTeX, 12 page

    Performance of the LHC Final Prototype and First Pre-series Superconducting Dipole Magnets

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    Within the LHC cryo-dipole program, six full-scale superconducting prototypes of final design were built in collaboration between Industry and CERN, followed by launching the manufacture of pre-series magnets. Five prototypes and the first of the pre-series magnets were tested at CERN. This paper reviews the main features and the performance of the cryo-dipoles tested at 4.2 K and 1.8 K. The results of the quench training, conductor performance, magnet protection, sensitivity to ramp rate and field characteristics are presented and discussed in terms of the design parameters

    All-sky upper limit for gravitational radiation from spinning neutron stars

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    We present results of the all-sky search for gravitational-wave signals from spinning neutron stars in the data of the EXPLORER resonant bar detector. Our data analysis technique was based on the maximum likelihood detection method. We briefly describe the theoretical methods that we used in our search. The main result of our analysis is an upper limit of 2×1023{\bf 2\times10^{-23}} for the dimensionless amplitude of the continuous gravitational-wave signals coming from any direction in the sky and in the narrow frequency band from 921.00 Hz to 921.76 Hz.Comment: 12 pages, 4 figures, submitted to Proceedings of 7th Gravitational Wave Data Analysis Workshop, December 17-19, 2002, Kyoto, Japa

    Design, Manufacturing Status, First Results of the LHC Main Dipole Final Prototypes and Steps towards Series Manufacture

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    This paper reports about the program of six LHC superconducting main dipole final prototypes and the steps towards series manufacture. The above program, launched in summer 1998, relies on collared coils manufactured by industry and cold masses assembled at the CERN Magnet Assembly Facility. Following design, stability and robustness studies, the magnet design for series manufacture features a "6-block" coil and austenitic steel collars. A general description of the magnet with its main components is given and the main working parameters and the most important manufacturing features are presented. Results of mechanical and magnetic measurements are given as well as the performances of the first prototype. A comparison with results from the previous generation of dipole magnet models and prototypes is also made. Finally an outlook towards series manufacture is given

    Clinical, radiologic, pathologic, and molecular characteristics of long-term survivors of diffuse intrinsic pontine glioma (DIPG): a collaborative report from the International and European Society for Pediatric Oncology DIPG registries

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    Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of < 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age < 3 or > 10 years (11% v 3% and 33% v 23%, respectively; P < .001) and with longer symptom duration ( P < .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials
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