601 research outputs found
Applicability of a Representation for the Martin's Real-Part Formula in Model-Independent Analyses
Using a novel representation for the Martin's real-part formula without the
full scaling property, an almost model-independent description of the
proton-proton differential cross section data at high energies (19.4 GeV - 62.5
GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted
inelastic overlap function presents a peripheral effect (tail) above 2 fm and
the extracted opacity function is characterized by a zero (change of sign) in
the momentum transfer space, confirming results from previous model-independent
analyses. Analytical parametrization for these empirical results are introduced
and discussed. The importance of investigations on the inverse problems in
high-energy elastic hadron scattering is stressed and the relevance of the
proposed representation is commented. A short critical review on the use of
Martin's formula is also presented.Comment: Two comments and one reference added at the end of Subsec. 3.3; 23
pages, 9 figures; to be published in Int. J. Mod. Phys.
Intravascular myopericytoma in the heel: Case report and literature review
Intravascular myopericytoma (IVMP), regarded as a variant of myopericytoma, is a rare tumor. Very few cases have been described, none in the foot.
The first case of IVMP located in the heel of the foot is described in this article. A literature review is reported of all cases of IVMP published in the English literature.
A 48-year-old man possessed an IVMP on the heel of the right foot. The physical examination and histopathological and ultrasound studies are described. The literature review yielded 5 cases of IVMP, 2 of which were in the thigh and 1 each in the oral mucosa, the periorbital region, and the leg.
The possibility that these lesions may be malignant suggests that the histopathological study of vascular tumors should include immunohistochemical tests
A new surgical procedure for hallux limitus treatment: Double-V osteotomy on the base of the proximal phalanx of the hallux
The purpose of this study was to evaluate the effectiveness of the new Double-V osteotomy of the first metatarsophalangeal joint (1 st MPJ) in patients with hallux limitus (HL). A study of 66 patients was performed, 33 patients were treated Cheilectomy and 33 were treated Double-V. All patients underwent an assessment of the passive mobility of the 1 st MPJ before the procedure, reevaluated 12 months later evaluating dorsiflexion, plantarflexion, and patients status using both the American Orthopaedic Foot and Ankle Society (AOFAS) for Hallux Metatarsophalangeal-Interphalangeal Scale. In comparing the improvement achieved regarding the increase of mobility obtained with surgical treatment, the feet operated with procedure Double-V gained significant degrees of movement increased in all analyzed parameters (P<.05). We achieved 13.33° more than average in dorsiflexion motion and 2.12° more than average in plantarflexion with regard to the feet that were operated with Cheilectomy procedure. Double-V scores on the AOFAS scale improved significantly (P=.000) 91.48 points postoperative, while with the following Cheilectomy only 79.30 points. This new surgical technique, easy to perform and with low complexity in surgical execution and a minimum of complications, produces better clinical and functional results that Cheilectomy alone
A model for net-baryon rapidity distribution
In nuclear collisions, a sizable fraction of the available energy is carried
away by baryons. As the baryon number is conserved, the net-baryon
retains information on the energy-momentum carried by the incoming nuclei. A
simple and consistent model for net-baryon production in high energy
proton-proton and nucleus-nucleus collisions is presented. The basic
ingredients of the model are valence string formation based on standard PDFs
with QCD evolution and string fragmentation via the Schwinger mechanism. The
results of the model are presented and compared with data at different
centre-of-mass energies and centralities, as well as with existing models.
These results show that a good description of the main features of net-baryon
data is possible in the framework of a simplistic model, with the advantage of
making the fundamental production mechanisms manifest.Comment: 9 pages, 12 figures; in fig. 11 a) the vertical scale was correcte
The current knowledge on Anastrepha Schiner (Dip., Tephritidae) in the State of Amapá, Brazil.
Resumo simples
Factorial Moments in a Generalized Lattice Gas Model
We construct a simple multicomponent lattice gas model in one dimension in
which each site can either be empty or occupied by at most one particle of any
one of species. Particles interact with a nearest neighbor interaction
which depends on the species involved. This model is capable of reproducing the
relations between factorial moments observed in high--energy scattering
experiments for moderate values of . The factorial moments of the negative
binomial distribution can be obtained exactly in the limit as becomes
large, and two suitable prescriptions involving randomly drawn nearest neighbor
interactions are given. These results indicate the need for considerable care
in any attempt to extract information regarding possible critical phenomena
from empirical factorial moments.Comment: 15 pages + 1 figure (appended as postscript file), REVTEX 3.0,
NORDITA preprint 93/4
Production of Secondaries in High Energy d+Au Collisions
In the framework of Quark-Gluon String Model we calculate the inclusive
spectra of secondaries produced in d+Au collisions at intermediate (CERN SPS)
and at much higher (RHIC) energies. The results of numerical calculations at
intermediate energies are in reasonable agreement with the data. At RHIC
energies numerically large inelastic screening corrections (percolation
effects) should be accounted for in calculations. We extract these effects from
the existing RHIC experimental data on minimum bias and central d+Au
collisions. The predictions for p+Au interactions at LHC energy are also given.Comment: 18 pages and 10 figure
Percolation of Color Sources and the determination of the Equation of State of the Quark-Gluon Plasma (QGP) produced in central Au-Au collisions at \sqrt S_{NN}= 200 GeV
The Color String Percolation Model (CSPM) is used to determine the equation
of state (EOS) of the QGP produced in central Au-Au collisions at
= 200 A GeV using STAR data at RHIC. When the initial density
of interacting colored strings exceeds the 2D percolation threshold a cluster
is formed, which defines the onset of color deconfinement. These interactions
also produce fluctuations in the string tension which transforms the Schwinger
particle (gluon) production mechanism into a maximum entropy thermal
distribution. The single string tension is determined by identifying the known
value of the universal hadron limiting temperature = 167.7 2.6
MeV with the CSPM percolation temperature at the critical threshold
=1.2. At mid-rapidity the initial Bjorken energy density and the initial
temperature determine the number of degrees of freedom consistent with the
formation of a 2+1 flavor QGP. An analytic expression for the equation
of state, the sound velocity is obtained in CSPM. The CSPM
and the bulk thermodynamic values and are in excellent agreement in the phase transition region with recent
lattice QCD simulations (LQCD) by the HotQCD Collaboration.Comment: 4 pages, 3 figure
Functional magnetic resonance imaging evaluation of pain central sensitization phenomena in subjects with knee osteoarthritis
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