2,562 research outputs found
A search for light dark matter in XENON10 data
We report results of a search for light (<10 GeV) particle dark matter with
the XENON10 detector. The event trigger was sensitive to a single electron,
with the analysis threshold of 5 electrons corresponding to 1.4 keV nuclear
recoil energy. Considering spin-independent dark matter-nucleon scattering, we
exclude cross sections \sigma_n>3.5x10^{-42} cm^2, for a dark matter particle
mass m_{\chi}=8 GeV. We find that our data strongly constrain recent elastic
dark matter interpretations of excess low-energy events observed by CoGeNT and
CRESST-II, as well as the DAMA annual modulation signal.Comment: Manuscript identical to v2 (published version) but also contains
erratum. Note v3==v2 but without \linenumber
Voting 'against all' in postcommunist Russia
Since the early 1990s voters in Russia (and most of the other post-Soviet republics) have been offered
the opportunity to vote ‘against all’ parties and candidates. Increasing numbers have done so. The
evidence of two post-election surveys indicates that ‘against all’ voters are younger than other voters,
more urban and more highly educated. They do not reject liberal democracy, but are critical of the
contemporary practice of Russian politics and find no parties that adequately reflect their views. With
the ending of the ‘against all’ facility in 2006 and other changes in the Russian electoral system under
the Putin presidency, levels of turnout are likely to fall further and the protest vote will seek other
outlets within or outside the parliamentary system
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Snake venom phospholipase A2s exhibit strong virucidal activity against SARS-CoV-2 and inhibit the viral spike glycoprotein interaction with ACE2.
The COVID-19 pandemic caused by SARS-CoV-2 requires new treatments both to alleviate the symptoms and to prevent the spread of this disease. Previous studies demonstrated good antiviral and virucidal activity of phospholipase A2s (PLA2s) from snake venoms against viruses from different families but there was no data for coronaviruses. Here we show that PLA2s from snake venoms protect Vero E6 cells against SARS-CoV-2 cytopathic effects. PLA2s showed low cytotoxicity to Vero E6 cells with some activity at micromolar concentrations, but strong antiviral activity at nanomolar concentrations. Dimeric PLA2 from the viper Vipera nikolskii and its subunits manifested especially potent virucidal effects, which were related to their phospholipolytic activity, and inhibited cell-cell fusion mediated by the SARS-CoV-2 spike glycoprotein. Moreover, PLA2s interfered with binding both of an antibody against ACE2 and of the receptor-binding domain of the glycoprotein S to 293T/ACE2 cells. This is the first demonstration of a detrimental effect of PLA2s on β-coronaviruses. Thus, snake PLA2s are promising for the development of antiviral drugs that target the viral envelope, and could also prove to be useful tools to study the interaction of viruses with host cells
Scintillator counters with multi-pixel avalanche photodiode readout for the ND280 detector of the T2K experiment
The Tokai-to-Kamioka (T2K) experiment is a second generation long baseline neutrino oscillation experiment which aims at a sensitive search for νe appearance. The main design features of the T2K near neutrino detectors located at 280 m from the target are presented, and the scintillator counters are described. The counters are readout via WLS fibers embedded into S-shaped grooves in the scintillator from both ends by multi-pixel avalanche photodiodes operating in a limited Geiger mode. Operating principles and results of tests of photosensors with a sensitive area of 1 mm2 are presented. A time resolution of 1.75 ns, a spatial resolution of 9.9 - 12.4 cm, and a detection efficiency for minimum ionizing particles of more than 99% were obtained for scintillator detectors in a beam test. © 2007 Elsevier B.V. All rights reserved
ChPT tests at the NA48 and NA62 experiments at CERN
The NA48/2 Collaboration at CERN has accumulated unprecedented statistics of
rare kaon decays in the Ke4 modes: Ke4(+-) ()
and Ke4(00) () with nearly one percent
background contamination. The detailed study of form factors and branching
rates, based on these data, has been completed recently. The results brings new
inputs to low energy strong interactions description and tests of Chiral
Perturbation Theory (ChPT) and lattice QCD calculations. In particular, new
data support the ChPT prediction for a cusp in the invariant mass
spectrum at the two charged pions threshold for Ke4(00) decay. New final
results from an analysis of about 400 rare
decay candidates collected by the NA48/2 and NA62 experiments at CERN during
low intensity runs with minimum bias trigger configurations are presented. The
results include a model-independent decay rate measurement and fits to ChPT
description.Comment: XIIth International Conference on Heavy Quarks and Leptons 2014,
Mainz, German
Prospects for at CERN in NA62
The NA62 experiment will begin taking data in 2015. Its primary purpose is a
10% measurement of the branching ratio of the ultrarare kaon decay , using the decay in flight of kaons in an unseparated
beam with momentum 75 GeV/c.The detector and analysis technique are described
here.Comment: 8 pages for proceedings of 50 Years of CP
Anti-inflammatory and immunomodulating effects of the bacterial lysate in the <em>in vivo</em> models of aseptic lymphadenitis and pneumococcal pneumonia
Bacterial lysates may produce immunoregulatory effects in the inflammatory diseases that are not directly caused by infectious agents; they may also stimulate the immune response against pathogens which are not a part of the lysate composition. Imudon® is a polyvalent bacterial lysate that is available in orodispersible tablets. However, the influence of this drug product on aseptic inflammation and immune defense against the infectious agents, the antigens of which are not contained in this preparation have not been studied so far. The aim of this study, therefore, was to determine the anti-inflammatory and immunomodulating effects of Imudon® using the models of aseptic lymphadenitis (in Wistar rats) and pneumococcal pneumonia (in Balb/c mice), i.e., the conditions not related to the specific components of the bacterial lysate. Lymphadenitis was induced in rats by administration of λ-carrageenan into a cervical lymph node via an open operative approach. Whereas pneumonia was induced in mice by administering Streptococcus pneumoniae suspension intranasally. The choice of pneumococcus was determined by the absence of pneumococcal antigens in Imudon®, i.e., it cannot be a direct inducer of adaptive immune response against pneumococcal infection. Imudon® was administered intragastrically as a crushed tablet suspension following a therapeutic-preventive regimen (for 14 days daily until the induction of inflammation and for 3 [in the lymphadenitis model] or 5 days [in the model of pneumonia] in three doses thereafter). In the lymphadenitis model, Imudon® demonstrated both local and systemic anti-inflammatory responses manifested in the reduced number of circulating leucocytes and lower TNFα levels and by ameliorated histological features of inflammation in the operated lymph node. In rats, the anti-inflammatory effect was most pronounced when the product was administered at a dose of 2.2 mg/kg (equivalent to a human therapeutic dose) and 6.6 mg/kg. In the model of pneumonia, administration of Imudon® at 4.44 mg/kg (equivalent to a human therapeutic dose) and 13.32 mg/kg demonstrated a trend towards increased survival rate as compared to the control group. On Day 5 after infection Imudon® (4.44 and 13.32 mg/kg) decreased significantly the severity of inflammation and bacterial titer in the lungs. The titer of anti-pneumococcal immunoglobulins A in the bronchoalveolar lavage fluid were found to be higher in the Imudon® treated group (13.32 mg/kg) compared to control group. The results of this study showed high antiinflammatory and immunomodulatory activities of Imudon® and provided an insight into the mechanisms that underlie the clinical effects of this drug in various inflammatory diseases
Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−
The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions
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