462 research outputs found
A role for TSPO in mitochondrial Ca2+ homeostasis and redox stress signaling
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 decay
We report the first lattice QCD calculation of the complex kaon decay
amplitude with physical kinematics, using a lattice
volume and a single lattice spacing , with GeV. We find
Re GeV and Im GeV, where the first error is statistical
and the second systematic. The first value is in approximate agreement with the
experimental result: Re GeV while the second
can be used to compute the direct CP violating ratio
Re, which is
below the experimental value . The real
part of is CP conserving and serves as a test of our method while the
result for Re 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
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 degree of freedom is superimposed on 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
We present results for several light hadronic quantities (, ,
, , , , ) 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 , and 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: = 130.2(9) MeV; = 155.5(8) MeV; the
average up/down quark mass and strange quark mass in the scheme
at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon
mixing parameter, , in the RGI scheme, 0.750(15) and the
scheme at 3 GeV, 0.530(11).Comment: 131 pages, 30 figures. Updated to match published versio
Experimental quantum tossing of a single coin
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
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
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
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
Rho decay width from the lattice
The XXVIII International Symposium on Lattice Field Theory, June 14-19, 2010, Villasimius, Sardinia ItalyInternational audienceWhile the masses of light hadrons have been extensively studied in lattice QCD simulations, there exist only a few exploratory calculations of the strong decay widths of hadronic resonances. We will present preliminary results of a computation of the rho meson width obtained using flavor simulations. The work is based on L\"uscher's formalism and its extension to moving frames
- …