194 research outputs found

    Principal Component Analysis of Cavity Beam Position Monitor Signals

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    Model-independent analysis (MIA) methods are generally useful for analysing complex systems in which relationships between the observables are non-trivial and noise is present. Principle Component Analysis (PCA) is one of MIA methods allowing to isolate components in the input data graded to their contribution to the variability of the data. In this publication we show how the PCA can be applied to digitised signals obtained from a cavity beam position monitor (CBPM) system on the example of a 3-cavity test system installed at the Accelerator Test Facility 2 (ATF2) at KEK in Japan. We demonstrate that the PCA based method can be used to extract beam position information, and matches conventional techniques in terms of performance, while requiring considerably less settings and data for calibration

    Dendritic cells cross talk with tumor antigen-specific CD8+T cells, Vγ9γδT cells, and Vα24NKT cells in patients with glioblastoma multiforme and in healthy donors

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    The finding that dendritic cells (DCs) orchestrate innate and adaptive immune responses has stimulated research on harnessing DCs for developing more effective vaccines for DC therapy. The expression of cytomegalovirus (CMV) antigens in glioblastoma multiforme (GBM) presents a unique opportunity to target these viral proteins for tumor immunotherapy. Here, we demonstrate that Vγ9γδT cells, innate immune cells activated by zoledronate (Z), and Vα24NKT cells, innate/adaptive immune cells activated by α-galactosylceramide (G) can link innate and adaptive immunities through cross talk with IFN-DCs from patients with GBM and healthy donors in a way that can amplify the activation and proliferation of CMVpp65-specific CD8+T cells. The IFN-DCs derived from patients with GBM used in this study express lower levels of programmed death ligand (PDL)1 and PDL2 and higher levels of CCR7 than the most commonly used mature IL-4DCs. The expression level of programmed cell death 1 (PD1) on CD8+ T cells, including CMVpp65-specific CD8+T cells, expanded by IFN-DCs pulsed with the CMVpp65-peptide and Z plus G (IFN-DCs/P+Z+G) was lower than that expanded by IFN-DCs pulsed with the peptide alone (IFN-DCs/P). Multifunctional T cells, including HLA-A*0201-restricted CMVpp65-specific CD8+T cells, Vγ9γδT cells, and Vα24NKT cells, efficiently kill HLA-A*0201 positive GBM cell line expressing CMVpp65 protein (T98G). These findings indicate that DC therapy using IFN-DCs/P+Z+G and/or CTL therapy using CMVpp65-specific CD8+T cells expanded by IFN-DCs/P+Z+G may lead to a good clinical outcome for patients with GBM. This article is protected by copyright. All rights reserved

    Photon generation by laser-Compton scattering at the KEK-ATF

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    We performed a photon generation experiment by laser-Compton scattering at the KEK-ATF, aiming to develop a Compton based polarized positron source for linear colliders. In the experiment, laser pulses with a 357 MHz repetition rate were accumulated and their power was enhanced by up to 250 times in the Fabry-Perot optical resonant cavity. We succeeded in synchronizing the laser pulses and colliding them with the 1.3 GeV electron beam in the ATF ring while maintaining the laser pulse accumulation in the cavity. As a result, we observed 26.0 +/- 0.1 photons per electron-laser pulse crossing, which corresponds to a yield of 10^8 photons in a second.Comment: 3 pages, 5 figures, Preprint submitted to TIPP09 Proceedings in NIM

    IL-12 Production Induced by Agaricus blazei Fraction H (ABH) Involves Toll-like Receptor (TLR)

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    Agaricus blazei Murill is an edible fungus used in traditional medicine, which has various well-documented medicinal properties. In the present study, we investigated the effects of hemicellulase-derived mycelia extract (Agaricus blazei fraction H: ABH) on the immune system. First, we examined the cytokine-inducing activity of ABH on human peripheral mononuclear cells (PBMC). The results indicated that ABH induced expression of IL-12, a cytokine known to be a critical regulator of cellular immune responses. Flow cytometric analysis demonstrated the induction of IL-12 production by the CD14-positive cell population, consisting of monocytes/macrophages (Mo/Mφ). Furthermore, the elimination of Mo/Mφ attenuated IL-12 production in PBMC. ABH-induced IL-12 production was inhibited by anti-CD14 and anti-TLR4 antibodies but not by anti-TLR2 antibody. The activity of ABH was not inhibited by polymyxin B, while the activity of lipopolysaccharide used as a reference was inhibited. Oral administration of ABH enhanced natural killer (NK) activity in the spleen. These findings suggest that ABH activated Mo/Mφ in a manner dependent on CD14/TLR4 and NK activity

    Design of a Polarised Positron Source Based on Laser Compton Scattering

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    We describe a scheme for producing polarised positrons at the ILC from polarised X-rays created by Compton scattering of a few-GeV electron beam off a CO2 or YAG laser. This scheme is very energy effective using high finesse laser cavities in conjunction with an electron storage ring.Comment: Proposal submitted to the ILC workshop, Snowmass 2005. v2: note number adde

    High flux polarized gamma rays production: first measurements with a four-mirror cavity at the ATF

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    The next generation of e+/e- colliders will require a very intense flux of gamma rays to allow high current polarized positrons to be produced. This can be achieved by converting polarized high energy photons in polarized pairs into a target. In that context, an optical system consisting of a laser and a four-mirror passive Fabry-Perot cavity has recently been installed at the Accelerator Test Facility (ATF) at KEK to produce a high flux of polarized gamma rays by inverse Compton scattering. In this contribution, we describe the experimental system and present preliminary results. An ultra-stable four-mirror non planar geometry has been implemented to ensure the polarization of the gamma rays produced. A fiber amplifier is used to inject about 10W in the high finesse cavity with a gain of 1000. A digital feedback system is used to keep the cavity at the length required for the optimal power enhancement. Preliminary measurements show that a flux of about 4×106γ4\times10^6 \gamma/s with an average energy of about 24 MeV was generated. Several upgrades currently in progress are also described

    Nanometer Order of Stabilization for Precision Beam Size Monitor (Shintake Monitor)

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    Original publication available at http://www.jacow.org/International audienceA precision beam size monitor using interference fringes as a reference called Shintake monitor[1] has been developed. Relative position between the beam and the interference fringes should be stabilized within few nm to measure the beam size of 37 nm with resolution of better than 10%. This paper presents concept and performances for stabilization of the Shintake monitor with respect to vibrations. We stabilized the table for the interferometer using a method, "Rigid mount on floor", and the table motions relative to the floor are estimated to be 2 and 6 n
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