702 research outputs found
Tensor analyzing power Ayy in deuteron inclusive breakup at large Pt and spin structure of deuteron at short internucleonic distances
The Ayy data for deuteron inclusive breakup off hydrogen and carbon at a
deuteron momentum of 9.0 GeV/c and large Pt of emitted protons are presented.
The large values of Ayy independent of the target mass reflect the sensitivity
of the data to the deuteron spin structure. The data obtained at fixed and
plotted versus Pt clearly demonstrate the dependence of the deuteron spin
structure at short internucleonic distances on two variables. The data are
compared with the calculations using Paris, CD-Bonn and Karmanov's deuteron
wave functions.Comment: 4 pages, 2 figures, talk given at the SPIN2004 Conf., 10-16 Oct.
2004, Triest, Ital
Structural phase transitions in the kagome lattice based materials Cs2-xRbxSnCu3F12 (x = 0, 0.5, 1.0, 1.5)
The solid solution Cs2-xRbxSnCu3F12 (x = 0, 0.5, 1.0, 1.5) has been
investigated crystallographically between 100 and 300 K using synchrotron X-ray
powder diffraction and, in the case of x = 0, neutron powder diffraction.Comment: 14 pages, 9 figure
Structural Basis for the Recognition of Cellular mRNA Export Factor REF by Herpes Viral Proteins HSV-1 ICP27 and HVS ORF57
The herpesvirus proteins HSV-1 ICP27 and HVS ORF57 promote viral mRNA export by utilizing the cellular mRNA export machinery. This function is triggered by binding to proteins of the transcription-export (TREX) complex, in particular to REF/Aly which directs viral mRNA to the TAP/NFX1 pathway and, subsequently, to the nuclear pore for export to the cytoplasm. Here we have determined the structure of the REF-ICP27 interaction interface at atomic-resolution and provided a detailed comparison of the binding interfaces between ICP27, ORF57 and REF using solution-state NMR. Despite the absence of any obvious sequence similarity, both viral proteins bind on the same site of the folded RRM domain of REF, via short but specific recognition sites. The regions of ICP27 and ORF57 involved in binding by REF have been mapped as residues 104–112 and 103–120, respectively. We have identified the pattern of residues critical for REF/Aly recognition, common to both ICP27 and ORF57. The importance of the key amino acid residues within these binding sites was confirmed by site-directed mutagenesis. The functional significance of the ORF57-REF/Aly interaction was also probed using an ex vivo cytoplasmic viral mRNA accumulation assay and this revealed that mutants that reduce the protein-protein interaction dramatically decrease the ability of ORF57 to mediate the nuclear export of intronless viral mRNA. Together these data precisely map amino acid residues responsible for the direct interactions between viral adaptors and cellular REF/Aly and provide the first molecular details of how herpes viruses access the cellular mRNA export pathway
АНТИКРИЗИСНОЕ УПРАВЛЕНИЕ ФИНАНСОВО-ЭКОНОМИЧЕСКОЙ УСТОЙЧИВОСТЬЮ ПРОМЫШЛЕННОГО ПРЕДПРИЯТИЯ
This article describes economic relations, associated with the management of an industrial enterprise using a budgeting system integrated with a quality management system. The Article covers the problems of defining key performance indicators and performance criteria in the budgeting system processes of industrial enterprises.Cтатья посвящена разработке организационно-экономического механизма антикризисного управления финансово-экономической устойчивостью промышленного предприятия на основе интеграции системы бюджетирования с системой менеджмента качества с использованием системы целевых показателей и критериев результативности процессов в рамках системы бюджетирования
Graphene as a transparent conductive support for studying biological molecules by transmission electron microscopy
We demonstrate the application of graphene as a support for imaging
individual biological molecules in transmission electron microscope (TEM). A
simple procedure to produce free-standing graphene membranes has been designed.
Such membranes are extremely robust and can support practically any
sub-micrometer object. Tobacco mosaic virus has been deposited on graphene
samples and observed in a TEM. High contrast has been achieved even though no
staining has been applied
Tensor Ayy and vector Ay analyzing powers in the H(d,d')X and ^{12}C(d,d')X reactons at initial deuteron momenta of 9 GeV/c in the region of baryonic resonances excitation
The angular dependence of the tensor Ayy and vector Ay analyzing powers in
the inelastic scattering of deuterons with a momentum of 9.0 GeV/c on hydrogen
and carbon have been measured. The range of measurements corresponds to the
baryonic resonance excitation with masses 2.2--2.6 GeV/c^2. The Ayy data being
in good agreement with the previous results demonstrate an approximate
scaling up to -1.5 (GeV/c)^2. The large values of A_y show a significant role
of the spin-dependent part of the elementary amplitude of the NN->NN* reaction.
The results of the experiment are compared with model predictions of the
plane-wave impulse approximation.Comment: 7 pages, 7 figures. submitted to Yad.Fi
Competitive and Cooperative Interactions Mediate RNA Transfer from Herpesvirus Saimiri ORF57 to the Mammalian Export Adaptor ALYREF
The essential herpesvirus adaptor protein HVS ORF57, which has homologs in all other herpesviruses, promotes viral mRNA
export by utilizing the cellular mRNA export machinery. ORF57 protein specifically recognizes viral mRNA transcripts, and
binds to proteins of the cellular transcription-export (TREX) complex, in particular ALYREF. This interaction introduces viral
mRNA to the NXF1 pathway, subsequently directing it to the nuclear pore for export to the cytoplasm. Here we have used a
range of techniques to reveal the sites for direct contact between RNA and ORF57 in the absence and presence of ALYREF. A
binding site within ORF57 was characterized which recognizes specific viral mRNA motifs. When ALYREF is present, part of
this ORF57 RNA binding site, composed of an a-helix, binds preferentially to ALYREF. This competitively displaces viral RNA
from the a-helix, but contact with RNA is still maintained by a flanking region. At the same time, the flexible N-terminal
domain of ALYREF comes into contact with the viral RNA, which becomes engaged in an extensive network of synergistic
interactions with both ALYREF and ORF57. Transfer of RNA to ALYREF in the ternary complex, and involvement of individual
ORF57 residues in RNA recognition, were confirmed by UV cross-linking and mutagenesis. The atomic-resolution structure
of the ORF57-ALYREF interface was determined, which noticeably differed from the homologous ICP27-ALYREF structure.
Together, the data provides the first site-specific description of how viral mRNA is locked by a herpes viral adaptor protein in
complex with cellular ALYREF, giving herpesvirus access to the cellular mRNA export machinery. The NMR strategy used
may be more generally applicable to the study of fuzzy protein-protein-RNA complexes which involve flexible polypeptide
regions
Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster
Neutrino physics is nowadays receiving more and more attention as a possible
source of information for the long-standing problem of new physics beyond the
Standard Model. The recent measurement of the mixing angle in the
standard mixing oscillation scenario encourages us to pursue the still missing
results on leptonic CP violation and absolute neutrino masses. However,
puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE
Collaboration has been setup to undertake conclusive experiments to clarify the
muon-neutrino disappearance measurements at small , which will be able to
put severe constraints to models with more than the three-standard neutrinos,
or even to robustly measure the presence of a new kind of neutrino oscillation
for the first time. To this aim the use of the current FNAL-Booster neutrino
beam for a Short-Baseline experiment has been carefully evaluated. This
proposal refers to the use of magnetic spectrometers at two different sites,
Near and Far. Their positions have been extensively studied, together with the
possible performances of two OPERA-like spectrometers. The proposal is
constrained by availability of existing hardware and a time-schedule compatible
with the CERN project for a new more performant neutrino beam, which will
nicely extend the physics results achievable at the Booster. The possible FNAL
experiment will allow to clarify the current disappearance tension
with appearance and disappearance at the eV mass scale. Instead, a new
CERN neutrino beam would allow a further span in the parameter space together
with a refined control of systematics and, more relevant, the measurement of
the antineutrino sector, by upgrading the spectrometer with detectors currently
under R&D study.Comment: 76 pages, 52 figure
Measurement of the semileptonic charge asymmetry in B0 meson mixing with the D0 detector
We present a measurement of the semileptonic mixing asymmetry for B0 mesons,
a^d_{sl}, using two independent decay channels: B0 -> mu+D-X, with D- ->
K+pi-pi-; and B0 -> mu+D*-X, with D*- -> antiD0 pi-, antiD0 -> K+pi- (and
charge conjugate processes). We use a data sample corresponding to 10.4 fb^{-1}
of ppbar collisions at sqrt(s) = 1.96 TeV, collected with the D0 experiment at
the Fermilab Tevatron collider. We extract the charge asymmetries in these two
channels as a function of the visible proper decay length (VPDL) of the B0
meson, correct for detector-related asymmetries using data-driven methods, and
account for dilution from charge-symmetric processes using Monte Carlo
simulation. The final measurement combines four signal VPDL regions for each
channel, yielding a^d_{sl} = [0.68 \pm 0.45 \text{(stat.)} \pm 0.14
\text{(syst.)}]%. This is the single most precise measurement of this
parameter, with uncertainties smaller than the current world average of B
factory measurements.Comment: Version includes minor textual changes following peer review by
journal, most notably the updating of Ref. [21] to reflect the most recent
publicatio
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