9,290 research outputs found
Verification and Validation of Semantic Annotations
In this paper, we propose a framework to perform verification and validation
of semantically annotated data. The annotations, extracted from websites, are
verified against the schema.org vocabulary and Domain Specifications to ensure
the syntactic correctness and completeness of the annotations. The Domain
Specifications allow checking the compliance of annotations against
corresponding domain-specific constraints. The validation mechanism will detect
errors and inconsistencies between the content of the analyzed schema.org
annotations and the content of the web pages where the annotations were found.Comment: Accepted for the A.P. Ershov Informatics Conference 2019(the PSI
Conference Series, 12th edition) proceedin
Semileptonic transition in three--point QCD sum rules and HQET with gluon condensate corrections
Taking into account the gluon condensate contributions, the form factors of
the semileptonic transition with are
calculated in the framework of the three point QCD sum rules. The heavy quark
effective theory limit of the form factors are also computed. The relevant
total decay width as well as the branching ratio are evaluated and compared
with the predictions of the other non-perturbative approaches.Comment: 27 Pages, 4 Figures and 4 Table
L-selectin mediated leukocyte tethering in shear flow is controlled by multiple contacts and cytoskeletal anchorage facilitating fast rebinding events
L-selectin mediated tethers result in leukocyte rolling only above a
threshold in shear. Here we present biophysical modeling based on recently
published data from flow chamber experiments (Dwir et al., J. Cell Biol. 163:
649-659, 2003) which supports the interpretation that L-selectin mediated
tethers below the shear threshold correspond to single L-selectin carbohydrate
bonds dissociating on the time scale of milliseconds, whereas L-selectin
mediated tethers above the shear threshold are stabilized by multiple bonds and
fast rebinding of broken bonds, resulting in tether lifetimes on the timescale
of seconds. Our calculations for cluster dissociation suggest that
the single molecule rebinding rate is of the order of Hz. A similar
estimate results if increased tether dissociation for tail-truncated L-selectin
mutants above the shear threshold is modeled as diffusive escape of single
receptors from the rebinding region due to increased mobility. Using computer
simulations, we show that our model yields first order dissociation kinetics
and exponential dependence of tether dissociation rates on shear stress. Our
results suggest that multiple contacts, cytoskeletal anchorage of L-selectin
and local rebinding of ligand play important roles in L-selectin tether
stabilization and progression of tethers into persistent rolling on endothelial
surfaces.Comment: 9 pages, Revtex, 4 Postscript figures include
Translation from Classical Two-Way Automata to Pebble Two-Way Automata
We study the relation between the standard two-way automata and more powerful
devices, namely, two-way finite automata with an additional "pebble" movable
along the input tape. Similarly as in the case of the classical two-way
machines, it is not known whether there exists a polynomial trade-off, in the
number of states, between the nondeterministic and deterministic pebble two-way
automata. However, we show that these two machine models are not independent:
if there exists a polynomial trade-off for the classical two-way automata, then
there must also exist a polynomial trade-off for the pebble two-way automata.
Thus, we have an upward collapse (or a downward separation) from the classical
two-way automata to more powerful pebble automata, still staying within the
class of regular languages. The same upward collapse holds for complementation
of nondeterministic two-way machines.
These results are obtained by showing that each pebble machine can be, by
using suitable inputs, simulated by a classical two-way automaton with a linear
number of states (and vice versa), despite the existing exponential blow-up
between the classical and pebble two-way machines
Management of chest keloids
Keloid formation is one of the most challenging clinical problems in wound healing. With increasing frequency of open heart surgery, chest keloid formations are not infrequent in the clinical practice. The numerous treatment methods including surgical excision, intralesional steroid injection, radiation therapy, laser therapy, silicone gel sheeting, and pressure therapy underscore how little is understood about keloids. Keloids have a tendency to recur after surgical excision as a single treatment. Stretching tension is clearly associated with keloid generation, as keloids tend to occur on high tension sites such as chest region. The authors treated 58 chest keloid patients with surgical excision followed by intraoperative and postoperative intralesional steroid injection. Even with minor complications and recurrences, our protocol results in excellent outcomes in cases of chest keloids
Spin-Orbit-Induced Orbital Excitations in Sr2RuO4 and Ca2RuO4: A Resonant Inelastic X-ray Scattering Study
High-resolution resonant inelastic X-ray scattering (RIXS) at the oxygen
K-edge has been used to study the orbital excitations of Ca2RuO4 and Sr2RuO4.
In combination with linear dichroism X-ray absorption spectroscopy, the
ruthenium 4d-orbital occupation and excitations were probed through their
hybridization with the oxygen p-orbitals. These results are described within a
minimal model, taking into account crystal field splitting and a spin-orbit
coupling \lambda_{so}=200~meV. The effects of spin-orbit interaction on the
electronic structure and implications for the Mott and superconducting ground
states of (Ca,Sr)2RuO4 are discussed.Comment: accepted in PRB 201
Magnetic-field-induced spin excitations and renormalized spin gap of the underdoped superconductor LaSrCuO
High-resolution neutron inelastic scattering experiments in applied magnetic
fields have been performed on LaSrCuO (LSCO). In zero
field, the temperature dependence of the low-energy peak intensity at the
incommensurate momentum-transfer $\mathbf{Q}^{\
}_{\mathrm{IC}}=(0.5,0.5\pm\delta,0),(0.5\pm\delta,0.5,0)T^{\}_{c}$ which broadens and shifts to lower
temperature upon the application of a magnetic field along the c-axis. A
field-induced enhancement of the spectral weight is observed, but only at
finite energy transfers and in an intermediate temperature range. These
observations establish the opening of a strongly downward renormalized spin gap
in the underdoped regime of LSCO. This behavior contrasts with the observed
doping dependence of most electronic energy features.Comment: accepted for publication in Phys. Rev. Let
Two-particle decays of B_c meson into charmonium states
The factorization of hard and soft contributions into the hadronic decays of
B_c meson at large recoils is explored in order to evaluate the decay rates
into the S, P and D-wave charmonia associated with rho and pi. The constraints
of approach applicability and uncertainties of numerical estimates are
discussed. The mode with the J/psi in the final state is evaluated taking into
account the cascade radiative electromagnetic decays of excited P-wave states,
that enlarges the branching ratio by 20-25%.Comment: 13 pages, LaTeX axodraw-style, 1 figure, 2 table
Calculation of the B_{c}leptonic decay constant using the shifted N-expansion method
We give a review and present a comprehensive calculation for the leptonic
constant B_{c} of the low-lying pseudoscalar and vector states of B_{c}-meson
in the framework of static and QCD-motivated nonrelativistic potential models
taking into account the one-loop and two-loop QCD corrections in the short
distance coefficient that governs the leptonic constant of quarkonium
system. Further, we use the scaling relation to predict the leptonic constant
of the nS-states of the (b_bar)c system. Our results are compared with other
models to gauge the reliability of the predictions and point out differences.Comment: 26 page
Bloch bundles, Marzari-Vanderbilt functional and maximally localized Wannier functions
We consider a periodic Schroedinger operator and the composite Wannier
functions corresponding to a relevant family of its Bloch bands, separated by a
gap from the rest of the spectrum. We study the associated localization
functional introduced by Marzari and Vanderbilt, and we prove some results
about the existence and exponential localization of its minimizers, in
dimension d < 4. The proof exploits ideas and methods from the theory of
harmonic maps between Riemannian manifolds.Comment: 37 pages, no figures. V2: the appendix has been completely rewritten.
V3: final version, to appear in Commun. Math. Physic
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