4,083 research outputs found
Comparison of flight-measured and calculated temperatures on the space shuttle orbiter
Structural temperatures and thermal protection system surface temperatures were measured on the space shuttle during the flight of STS 5. The measured data are compared with values calculated at wing stations 134, 240, and 328 and at fuselage station 877. The theoretical temperatures were calculated using the structural performance and resizing finite element thermal analysis program. The comparisons show that the calculated temperatures are, generally, in good agreement with the measured data
Industrial structural geology : principles, techniques and integration : an introduction
The authors wish to acknowledge the generous financial support provided in association with this volume to the Geological Society and the Petroleum Group by Badley Geoscience Ltd, BP, CGG Robertson, Dana Petroleum Ltd, Getech Group plc, Maersk Oil North Sea UK Ltd, Midland Valley Exploration Ltd, Rock Deformation Research (Schlumberger) and Borehole Image & Core Specialists (Wildcat Geoscience, Walker Geoscience and Prolog Geoscience). We would like to thank the fine team at the Geological Society’s Publishing House for the excellent support and encouragement that they have provided to the editors and authors of this Special Publication.Peer reviewedPublisher PD
A system analysis of a suboptimal surgical experience
© 2009 Lee et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
An FeLoBAL Binary Quasar
In an ongoing infrared imaging survey of quasars at Keck Observatory, we have
discovered that the z=1.285 quasar SDSS J233646.2-010732.6 comprises two point
sources with a separation of 1.67". Resolved spectra show that one component is
a standard quasar with a blue continuum and broad emission lines; the other is
a broad absorption line (BAL) quasar, specifically, a BAL QSO with prominent
absorption from MgII and metastable FeII, making it a member of the ``FeLoBAL''
class. The number of known FeLoBALs has recently grown dramatically from a
single example to more than a dozen, including a gravitationally lensed example
and the binary member presented here, suggesting that this formerly rare object
may be fairly common. Additionally, the presence of this BAL quasar in a
relatively small separation binary adds to the growing evidence that the BAL
phenomenon is not due to viewing a normal quasar at a specific orientation, but
rather that it is an evolutionary phase in the life of many, if not all,
quasars, and is particularly associated with conditions found in interacting
systems.Comment: AASTEX 13 pp., 4 figs; accepted by ApJ Letter
Radiative Transitions in Charmonium from Lattice QCD
Radiative transitions between charmonium states offer an insight into the
internal structure of heavy-quark bound states within QCD. We compute, for the
first time within lattice QCD, the transition form-factors of various
multipolarities between the lightest few charmonium states. In addition, we
compute the experimentally unobservable, but physically interesting vector
form-factors of the and .
To this end we apply an ambitious combination of lattice techniques,
computing three-point functions with heavy domain wall fermions on an
anisotropic lattice within the quenched approximation. With an anisotropy
at we find a reasonable gross spectrum and a
hyperfine splitting , which compares favourably with
other improved actions.
In general, after extrapolation of lattice data at non-zero to the
photopoint, our results agree within errors with all well measured experimental
values. Furthermore, results are compared with the expectations of simple quark
models where we find that many features are in agreement; beyond this we
propose the possibility of constraining such models using our extracted values
of physically unobservable quantities such as the quadrupole moment.
We conclude that our methods are successful and propose to apply them to the
problem of radiative transitions involving hybrid mesons, with the eventual
goal of predicting hybrid meson photoproduction rates at the GlueX experiment.Comment: modified version as publishe
The Chlamydia trachomatis Type III Secretion Chaperone Slc1 Engages Multiple Early Effectors, Including TepP, a Tyrosine-phosphorylated Protein Required for the Recruitment of CrkI-II to Nascent Inclusions and Innate Immune Signaling
Chlamydia trachomatis, the causative agent of trachoma and sexually transmitted infections, employs a type III secretion (T3S) system to deliver effector proteins into host epithelial cells to establish a replicative vacuole. Aside from the phosphoprotein TARP, a Chlamydia effector that promotes actin re-arrangements, very few factors mediating bacterial entry and early inclusion establishment have been characterized. Like many T3S effectors, TARP requires a chaperone (Slc1) for efficient translocation into host cells. In this study, we defined proteins that associate with Slc1 in invasive C. trachomatis elementary bodies (EB) by immunoprecipitation coupled with mass spectrometry. We identified Ct875, a new Slc1 client protein and T3S effector, which we renamed TepP (Translocated early phosphoprotein). We provide evidence that T3S effectors form large molecular weight complexes with Scl1 in vitro and that Slc1 enhances their T3S-dependent secretion in a heterologous Yersinia T3S system. We demonstrate that TepP is translocated early during bacterial entry into epithelial cells and is phosphorylated at tyrosine residues by host kinases. However, TepP phosphorylation occurs later than TARP, which together with the finding that Slc1 preferentially engages TARP in EBs leads us to postulate that these effectors are translocated into the host cell at different stages during C.trachomatis invasion. TepP co-immunoprecipitated with the scaffolding proteins CrkI-II during infection and Crk was recruited to EBs at entry sites where it remained associated with nascent inclusions. Importantly, C. trachomatis mutants lacking TepP failed to recruit CrkI-II to inclusions, providing genetic confirmation of a direct role for this effector in the recruitment of a host factor. Finally, endocervical epithelial cells infected with a tepP mutant showed altered expression of a subset of genes associated with innate immune responses. We propose a model wherein TepP acts downstream of TARP to recruit scaffolding proteins at entry sites to initiate and amplify signaling cascades important for the regulation of innate immune responses to Chlamydia.Fil: Chen, Yi-Shan. University of Duke; Estados UnidosFil: Bastidas, Robert J.. University of Duke; Estados UnidosFil: Saka, Hector Alex. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. University of Duke; Estados UnidosFil: Carpenter, Victoria K.. Duke University Medical Center; . University of Duke; Estados UnidosFil: Richards, Kristian L.. Miami University; Estados UnidosFil: Plano, Gregory V.. Miami University; Estados UnidosFil: Valdivia, Raphael H.. University of Duke; Estados Unido
FIRST 0747+2739: A FIRST/2MASS Quasar with an Overabundance of C IV Absorption Systems
We present a Keck ESI spectrum of FIRST 074711.2+273904, a K=15.4 quasar with
redshift 4.11 that is detected by both FIRST and 2MASS. The spectrum contains
at least 14 independent C IV absorption systems longward of the Ly-alpha
forest. These systems are found over a path length of Delta z = 0.984,
constituting one of the highest densities per unit redshift of C IV absorption
ever observed. One of the C IV systems is trough-like and resembles a weak
BAL-type outflow. Two of the C IV are ``associated'' absorption systems with
|v|3000 km/s, eight are either
resolved or require multiple discrete systems to fit the line profiles. In
addition to C IV absorption, there are two low-ionization Mg II absorption
systems along with two damped Ly-alpha systems, at least one of which may be a
C IV system. The overdensity of C IV absorption spans a redshift range of Delta
z=1. Superclusters along the line of sight are unlikely to cause an overdensity
stretching over such a long redshift path, thus the absorption may be an
example of narrow, high-velocity, intrinsic absorption that originates from the
quasar. We suggest that this quasar is a member of a transitional class of BAL
quasars where we are just barely seeing the spatial, density, or temporal edge
of the BAL-producing region (or period); the multiple high-velocity absorption
systems may be the remnants (or precursors) of a stronger BAL outflow. If
correct, then some simpler absorption line complexes in other quasars may also
be due to outflowing rather than intervening material.Comment: 5 pages, 1 figure, 1 table, uses emulateapj5.sty; Accepted by ApJ
Letter
Clebsch-Gordan Construction of Lattice Interpolating Fields for Excited Baryons
Large sets of baryon interpolating field operators are developed for use in
lattice QCD studies of baryons with zero momentum. Operators are classified
according to the double-valued irreducible representations of the octahedral
group. At first, three-quark smeared, local operators are constructed for each
isospin and strangeness and they are classified according to their symmetry
with respect to exchange of Dirac indices. Nonlocal baryon operators are
formulated in a second step as direct products of the spinor structures of
smeared, local operators together with gauge-covariant lattice displacements of
one or more of the smeared quark fields. Linear combinations of direct products
of spinorial and spatial irreducible representations are then formed with
appropriate Clebsch-Gordan coefficients of the octahedral group. The
construction attempts to maintain maximal overlap with the continuum SU(2)
group in order to provide a physically interpretable basis. Nonlocal operators
provide direct couplings to states that have nonzero orbital angular momentum.Comment: This manuscript provides an anlytical construction of operators and
is related to hep-lat/0506029, which provides a computational construction.
This e-print version contains a full set of Clebsch-Gordan coefficients for
the octahedral grou
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