2,981 research outputs found
Stimulated Raman Adiabatic Passage via bright state in Lambda medium of unequal oscillator strengths
We consider the population transfer process in a Lambda-type atomic medium of
unequal oscillator strengths by stimulated Raman adiabatic passage via
bright-state (b-STIRAP) taking into account propagation effects. Using both
analytic and numerical methods we show that the population transfer efficiency
is sensitive to the ratio q_p/q_s of the transition oscillator strengths. We
find that the case q_p>q_s is more detrimental for population transfer process
as compared to the case where . For this case it is possible to
increase medium dimensions while permitting efficient population transfer. A
criterion determining the interaction adiabaticity in the course of propagation
process is found. We also show that the mixing parameter characterizing the
population transfer propagates superluminally
PQChPT with Staggered Sea and Valence Ginsparg-Wilson Quarks: Vector Meson Masses
We consider partially quenched, mixed chiral perturbation theory with
staggered sea and Ginsparg-Wilson valence quarks in order to extract a
chiral-continuum extrapolation expression for the vector meson mass up to order
O(a^2), at one-loop level. Based on general principles, we accomplish the task
without explicitly constructing a sophisticated, heavy vector meson chiral
Lagrangian.Comment: 12 pages, 1 figure, REVTe
Regge description of spin-spin asymmetry in photon diffractive dissociation
We explore the possibility whether the gluon helicity distribution can be extracted from a comparison of experimental data on the
longitudinal spin-spin asymmetry in diffractive deep
inelastic scattering with calculations performed within the framework of
perturbative QCD (pQCD). The data could be obtained at the future HERA collider
in scattering of polarized electrons/positrons off polarized protons. In this
paper we look for such kinematical regions where contributions to from
soft processes (reggeon exchanges) are suppressed to guarantee an applicability
of pQCD. It is shown that for the square of the center-of-mass energy
, the hadronic diffractive mass , the momentum transferred to the proton , and
the longitudinal spin-spin asymmetry due to reggeon
exchanges is less than 10^{-4}. This value is presumably lower than the
asymmetry which can be measured with modern experimental technique. This means
that the pQCD prediction can be reliably compared with data in this kinematical
region.Comment: 44 pages, LaTeX, 12 figure
Infinite-dimensional Compact Quantum Semigroup
In this paper we construct a compact quantum semigroup structure on the
Toeplitz algebra . The existence of a subalgebra, isomorphic to
the algebra of regular Borel's measures on a circle with convolution product,
in the dual algebra is shown. The existence of Haar functionals
in the dual algebra and in the above-mentioned subalgebra is proved. Also we
show the connection between and the structure of weak Hopf
algebra.Comment: 17 page
Linear Confinement for Mesons and Nucleons in AdS/QCD
By using a new parametrization of the dilaton field and including a cubic
term in the bulk scalar potential, we realize linear confinement in both meson
and nucleon sectors within the framework of soft-wall AdS/QCD. At the same time
this model also correctly incorporate chiral symmetry breaking. We compare our
resulting mass spectra with experimental data and find good agreement between
them.Comment: 14 pages, published version in JHE
Short-length storage of intense optical pulses in solid by adiabatic passage
We propose a novel scheme of storage of intense pulses which allows a
significant reduction of the storage length with respect to standard schemes.
This scheme is particularly adapted to store optical information in media with
fast relaxations.Comment: 7 pages, 5 figure
Instabilities of dispersion-managed solitons in the normal dispersion regime
Dispersion-managed solitons are reviewed within a Gaussian variational
approximation and an integral evolution model. In the normal regime of the
dispersion map (when the averaged path dispersion is negative), there are two
solitons of different pulse duration and energy at a fixed propagation
constant. We show that the short soliton with a larger energy is linearly
(exponentially) unstable. The other (long) soliton with a smaller energy is
linearly stable but hits a resonance with excitations of the dispersion map.
The results are compared with the results from the recent publicationsComment: 20 figures, 20 pages. submitted to Phys. Rev.
The prognostic value of ferritinemia level in patients with chronic hepatitis C
Aim of investigation. To study the effect of various factors on the blood ferritin level in patients with chronic hepatitis C (CHC) and baseline ferritin level on treatment response rate of pegilated interferon α-2a (PEG-IFN α-2a) combined to ribavirin (RBV). Material and methods. The level of ferritin was determined in 67 patients with CHC by two solid-phase sandwich immunoenzymatic assays. In 32 patients, who received PEG-IFN α-2a and RBV, it was determined on starting point, on the 12th week and after termination of therapy. Logistical regression has been applied to study effect of ferritin and other variables on frequency of sustained virologic response (SVR). Results. Elevated ferritin level was revealed in 34,3% of patients, and it was significantly higher in men, than in women (326,0±38,4 vs 108,2±44,7 ng/dl, p <0,05). The average level of ferritin in the patients included in PEGIFN α-2a and RBV group, prior to onset of treatment was normal (241,4±33,1), on the 12th week of treatment it turn to be elevated in 90% of patients with average level of 703,5±133,4 ng/dl (p=0,009 at comparison to initial level), and after the end of treatment course elevation was observed in 66,6% of patients at average value of 473,6±96,3 ng/dl (p=0,044 at to starting point, p=0,07 at comparison to the 12-th week data). By comparison of average levels of ferritin in patients with SVR at intake of PEG-IFN α-2a in combination to RBV and in patients without SVR the difference was also apparent, especially at the 12th week.Conclusions. Application of logistical regression analysis demonstrated, that the baseline ferritin level is independent predictor of sustained virologic response at treatment by pegilated interferon α-2a with ribavirin
Loss of epidermal Evi/Wls results in a phenotype resembling psoriasiform dermatitis
Cells of the epidermis renew constantly from germinal layer stem cells. Although epithelial cell differentiation has been studied in great detail and the role of Wnt signaling in this process is well described, the contribution of epidermal Wnt secretion in epithelial cell homeostasis remains poorly understood. To analyze the role of Wnt proteins in this process, we created a conditional knockout allele of the Wnt cargo receptor Evi/Gpr177/Wntless and studied mice that lacked Evi expression in the epidermis. We found that K14-Cre, Evi-LOF mice lost their hair during the first hair cycle, showing a reddish skin with impaired skin barrier function. Expression profiling of mutant and wild-type skin revealed up-regulation of inflammation-associated genes. Furthermore, we found that Evi expression in psoriatic skin biopsies is down-regulated, suggesting that Evi-deficient mice developed skin lesions that resemble human psoriasis. Immune cell infiltration was detected in Evi-LOF skin. Interestingly, an age-dependent depletion of dendritic epidermal T cells (DETCs) and an infiltration of gammadelta(low) T cells in Evi mutant epidermis was observed. Collectively, the described inflammatory skin phenotype in Evi-deficient mice revealed an essential role of Wnt secretion in maintaining normal skin homeostasis by enabling a balanced epidermal-dermal cross talk, which affects immune cell recruitment and DETC survival
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