462 research outputs found

    A role for TSPO in mitochondrial Ca2+ homeostasis and redox stress signaling

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    The 18 kDa translocator protein TSPO localizes on the outer mitochondrial membrane (OMM). Systematically overexpressed at sites of neuroinflammation it is adopted as a biomarker of brain conditions. TSPO inhibits the autophagic removal of mitochondria by limiting PARK2-mediated mitochondrial ubiquitination via a peri-organelle accumulation of reactive oxygen species (ROS). Here we describe that TSPO deregulates mitochondrial Ca2+ signaling leading to a parallel increase in the cytosolic Ca2+ pools that activate the Ca2+-dependent NADPH oxidase (NOX) thereby increasing ROS. The inhibition of mitochondrial Ca2+ uptake by TSPO is a consequence of the phosphorylation of the voltage-dependent anion channel (VDAC1) by the protein kinase A (PKA), which is recruited to the mitochondria, in complex with the Acyl-CoA binding domain containing 3 (ACBD3). Notably, the neurotransmitter glutamate, which contributes neuronal toxicity in age-dependent conditions, triggers this TSPO-dependent mechanism of cell signaling leading to cellular demise. TSPO is therefore proposed as a novel OMM-based pathway to control intracellular Ca2+ dynamics and redox transients in neuronal cytotoxicity

    Standard-model prediction for direct CP violation in KππK\to\pi\pi decay

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    We report the first lattice QCD calculation of the complex kaon decay amplitude A0A_0 with physical kinematics, using a 323×6432^3\times 64 lattice volume and a single lattice spacing aa, with 1/a=1.3784(68)1/a= 1.3784(68) GeV. We find Re(A0)=4.66(1.00)(1.26)×107(A_0) = 4.66(1.00)(1.26) \times 10^{-7} GeV and Im(A0)=1.90(1.23)(1.08)×1011(A_0) = -1.90(1.23)(1.08) \times 10^{-11} GeV, where the first error is statistical and the second systematic. The first value is in approximate agreement with the experimental result: Re(A0)=3.3201(18)×107(A_0) = 3.3201(18) \times 10^{-7} GeV while the second can be used to compute the direct CP violating ratio Re(ε/ε)=1.38(5.15)(4.59)×104(\varepsilon'/\varepsilon)=1.38(5.15)(4.59)\times 10^{-4}, which is 2.1σ2.1\sigma below the experimental value 16.6(2.3)×10416.6(2.3)\times 10^{-4}. The real part of A0A_0 is CP conserving and serves as a test of our method while the result for Re(ε/ε)(\varepsilon'/\varepsilon) provides a new test of the standard-model theory of CP violation, one which can be made more accurate with increasing computer capability.Comment: 9 pages, 3 figures. Updated to match published versio

    Electromagnetic corrections to light hadron masses

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    At the precision reached in current lattice QCD calculations, electromagnetic effects are becoming numerically relevant. We will present preliminary results for electromagnetic corrections to light hadron masses, based on simulations in which a U(1)\mathrm{U}(1) degree of freedom is superimposed on Nf=2+1N_f=2+1 QCD configurations from the BMW collaboration.Comment: 7 pages, 2 figures, The XXVIII International Symposium on Lattice Field Theory, June 14-19,2010, Villasimius, Sardinia Ital

    Domain wall QCD with physical quark masses

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    We present results for several light hadronic quantities (fπf_\pi, fKf_K, BKB_K, mudm_{ud}, msm_s, t01/2t_0^{1/2}, w0w_0) obtained from simulations of 2+1 flavor domain wall lattice QCD with large physical volumes and nearly-physical pion masses at two lattice spacings. We perform a short, O(3)%, extrapolation in pion mass to the physical values by combining our new data in a simultaneous chiral/continuum `global fit' with a number of other ensembles with heavier pion masses. We use the physical values of mπm_\pi, mKm_K and mΩm_\Omega to determine the two quark masses and the scale - all other quantities are outputs from our simulations. We obtain results with sub-percent statistical errors and negligible chiral and finite-volume systematics for these light hadronic quantities, including: fπf_\pi = 130.2(9) MeV; fKf_K = 155.5(8) MeV; the average up/down quark mass and strange quark mass in the MSˉ\bar {\rm MS} scheme at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon mixing parameter, BKB_K, in the RGI scheme, 0.750(15) and the MSˉ\bar{\rm MS} scheme at 3 GeV, 0.530(11).Comment: 131 pages, 30 figures. Updated to match published versio

    Experimental quantum tossing of a single coin

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    The cryptographic protocol of coin tossing consists of two parties, Alice and Bob, that do not trust each other, but want to generate a random bit. If the parties use a classical communication channel and have unlimited computational resources, one of them can always cheat perfectly. Here we analyze in detail how the performance of a quantum coin tossing experiment should be compared to classical protocols, taking into account the inevitable experimental imperfections. We then report an all-optical fiber experiment in which a single coin is tossed whose randomness is higher than achievable by any classical protocol and present some easily realisable cheating strategies by Alice and Bob.Comment: 13 page

    K pi scattering for isospin 1/2 and 3/2 in lattice QCD

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    We simulate K pi scattering in s-wave and p-wave for both isospins I=1/2, 3/2 using quark-antiquark and meson-meson interpolating fields. We extract the elastic phase shifts delta at several values of the K-pi relative momenta. The resulting phases exhibit qualitative agreement with the experimental phases in all four channels. We express the s-wave phase shifts near threshold in terms of the scattering length and the effective range. Our K pi system has zero total momentum and is simulated on a single ensemble with two dynamical quarks, so results apply for mpi=266 MeV and mK=552 MeV in our simulation. The backtracking contractions in both I=1/2 channels are handled by the use of Laplacian-Heavyside smeared quarks within the distillation method. Elastic phases are extracted from the energy levels using Luscher's relations. In all four channels we observe the expected K(n)pi(-n) scattering states, which are shifted due to the interaction. In both attractive I=1/2 channels we observe additional states that are related to resonances; we attribute them to K_0^*(1430) in s-wave and K*(892), K*(1410) and K*(1680) in p-wave.Comment: 17 pages, 7 figures, version published in PR

    Applications of Nanoscale Materials in the Fields of Electrochemistry and Photoelectrochemistry

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    We have illustrated the important role played by the nanoscale materials in three-up-to-date energy topics

    An evidence review of research on health interventions in humanitarian crises. Final Report

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    This review was conducted to provide a rigorous assessment of the current quality and depth of the evidence-base that informs humanitarian public health programming globally. It assesses the quantity and quality of intervention studies, rather than measuring the actual effectiveness of the intervention itself. The review addresses evidence on interventions in humanitarian crises (including early recovery and forced displacement) for health topics of: communicable disease control water, sanitation and hygiene (WASH) nutrition sexual and reproductive health (SRH), including gender-based violence (GBV) mental health and psychosocial support non-communicable disease (NCD) injury and physical rehabilitation health services health systems. In addition, contextual factors influencing the delivery of health-related interventions are included in the project, consisting of: * access to health services * health assessment methods * coordination * accountability * health worker security * urbanisation. The evidence review used the following two main methods: (i) A series of systematic literature reviews on evidence of humanitarian interventions related to the health topics and on the influence of contextual factors on the interventions. The systematic review on evidence of interventions for the different health topics included quantitative evidence from published and grey literature. The systematic review on the contextual factors included quantitative and qualitative evidence from the published literature. Standard systematic review methodologies were used. (ii) Qualitative individual interviews with expert practitioners, policy makers and academics to identify critical weaknesses and gaps in the evidence base for humanitarian public health actions (including related to the contextual factors) and to recommend priority areas for further research. A series of more general consultations with humanitarian health experts through meetings in London, Geneva, Paris, and New York
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