220 research outputs found
A Novel Lumbar Motion Segment Classification to Predict Changes in Segmental Sagittal Alignment After Lateral Interbody Fixation.
Study designRetrospective cohort study.ObjectivesLateral interbody fixation is being increasingly used for the correction of segmental sagittal parameters. One factor that affects postoperative correction is the resistance afforded by posterior hypertrophic facet joints in the degenerative lumbar spine. In this article, we describe a novel preoperative motion segment classification system to predict postoperative correction of segmental sagittal alignment after lateral lumbar interbody fusion.MethodsPreoperative computed tomography scans were analyzed for segmental facet osseous anatomy for all patients undergoing lateral lumbar interbody fusion at 3 institutions. Each facet was assigned a facet grade (min = 0, max = 2), and the sum of the bilateral facet grades was the final motion segment grade (MSG; min = 0, max = 4). Preoperative and postoperative segmental lordosis was measured on standing lateral radiographs. Postoperative segmental lordosis was also conveyed as a percentage of the implanted graft lordosis (%GL). Simple linear regression was conducted to predict the postoperative segmental %GL according to MSG.ResultsA total of 36 patients with 59 operated levels were identified. There were 19 levels with MSG 0, 14 levels with MSG 1, 13 levels with MSG 2, 8 levels with MSG 3, and 5 levels with MSG 4. Mean %GL was 115%, 90%, 77%, 43%, and 5% for MSG 0 to 4, respectively. MSG significantly predicted postoperative %GL (P < .01). Each increase in MSG was associated with a 28% decrease in %GL.ConclusionsWe propose a novel facet-based motion segment classification system that significantly predicted postoperative segmental lordosis after lateral lumbar interbody fusion
The Updated Zwicky Catalog (UZC)
The Zwicky Catalog of galaxies (ZC), with m_Zw<=15.5mag, has been the basis
for the Center for Astrophysics (CfA) redshift surveys. To date, analyses of
the ZC and redshift surveys based on it have relied on heterogeneous sets of
galaxy coordinates and redshifts. Here we correct some of the inadequacies of
previous catalogs by providing: (1) coordinates with <~2 arcsec errors for all
of the Nuzc catalog galaxies, (2) homogeneously estimated redshifts for the
majority (98%) of the data taken at the CfA (14,632 spectra), and (3) an
estimate of the remaining "blunder" rate for both the CfA redshifts and for
those compiled from the literature. For the reanalyzed CfA data we include a
calibrated, uniformly determined error and an indication of the presence of
emission lines in each spectrum. We provide redshifts for 7,257 galaxies in the
CfA2 redshift survey not previously published; for another 5,625 CfA redshifts
we list the remeasured or uniformly re-reduced value. Among our new
measurements, Nmul are members of UZC "multiplets" associated with the original
Zwicky catalog position in the coordinate range where the catalog is 98%
complete. These multiplets provide new candidates for examination of tidal
interactions among galaxies. All of the new redshifts correspond to UZC
galaxies with properties recorded in the CfA redshift compilation known as
ZCAT. About 1,000 of our new measurements were motivated either by inadequate
signal-to-noise in the original spectrum or by an ambiguous identification of
the galaxy associated with a ZCAT redshift. The redshift catalog we include
here is ~96% complete to m_Zw<=15.5, and ~98% complete (12,925 galaxies out of
a total of 13,150) for the RA(1950) ranges [20h--4h] and [8h--17h] and
DEC(1950) range [-2.5d--50d]. (abridged)Comment: 34 pp, 7 figs, PASP 1999, 111, 43
Feynman scaling violation on baryon spectra in pp collisions at LHC and cosmic ray energies
A significant asymmetry in baryon/antibaryon yields in the central region of
high energy collisions is observed when the initial state has non-zero baryon
charge. This asymmetry is connected with the possibility of baryon charge
diffusion in rapidity space. Such a diffusion should decrease the baryon charge
in the fragmentation region and translate into the corresponding decrease of
the multiplicity of leading baryons. As a result, a new mechanism for Feynman
scaling violation in the fragmentation region is obtained. Another numerically
more significant reason for the Feynman scaling violation comes from the fact
that the average number of cutted Pomerons increases with initial energy. We
present the quantitative predictions of the Quark-Gluon String Model (QGSM) for
the Feynman scaling violation at LHC energies and at even higher energies that
can be important for cosmic ray physics.Comment: 21 pages, 11 figures, and 1 table. arXiv admin note: substantial text
overlap with arXiv:1107.1615, arXiv:1007.320
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
Multiscale modelling of vascular tumour growth in 3D: the roles of domain size & boundary condition
We investigate a three-dimensional multiscale model of vascular tumour growth, which couples blood flow, angiogenesis, vascular remodelling, nutrient/growth factor transport, movement of, and interactions between, normal and tumour cells, and nutrient-dependent cell cycle dynamics within each cell. In particular, we determine how the domain size, aspect ratio and initial vascular network influence the tumour's growth dynamics and its long-time composition. We establish whether it is possible to extrapolate simulation results obtained for small domains to larger ones, by constructing a large simulation domain from a number of identical subdomains, each subsystem initially comprising two parallel parent vessels, with associated cells and diffusible substances. We find that the subsystem is not representative of the full domain and conclude that, for this initial vessel geometry, interactions between adjacent subsystems contribute to the overall growth dynamics. We then show that extrapolation of results from a small subdomain to a larger domain can only be made if the subdomain is sufficiently large and is initialised with a sufficiently complex vascular network. Motivated by these results, we perform simulations to investigate the tumour's response to therapy and show that the probability of tumour elimination in a larger domain can be extrapolated from simulation results on a smaller domain. Finally, we demonstrate how our model may be combined with experimental data, to predict the spatio-temporal evolution of a vascular tumour
E2A/PBX1, MLL/AF4, BCR/ABL (M-BCR), BCR/ABL(m-BCR) gene rearrangements in acute lymphoblastic leukemia in Iranian children
Objectives: The following observation was primarily based on the study of gene fusion in blood and bone marrow cells taken from 68 Iranian children with acute lymphoblastic leukemia (ALL), to compare with healthy population. Methods: Peripheral blood and bone marrow samples obtained from patients with ALL were immunophenotyped to determine the lineage and the level of differentiation. With reverse transcriptase-polymerase chain reaction (RT-PCR), the RNA molecules were analyzed according to Van Dongen et al. protocol to detect fused genes in cell population. Results: Leukemic cell type was identified by cytochemical stains and classified on the basis of FAB classification. Nonetheless the frequencies of E2A/PBX1, MLL/AF4, BCR/ABL (M-BCR) and BCR/ABL(m-BCR) gene transcripts were 1.5, 0, 0 and 4.4 respectively. The positive case of E2A/PBX1 fusion gene had an early pre B and 3 BCR/ABL (m-BCR). Positive cases had an early pre B and pre-B ALL immunophenotype. Conclusions: Early pre-B cells were the most common types in our patients. The RT-PCR was shown to be an ideal method for detecting hybrid transcripts and to estimate the prevalence of the fusion genes in ALL patients. The frequency of these fusion genes in Iranian pediatric ALL patients were found to be similar to some developed countries. Thus, their presence does not seem to be predictive of increasing malignancy, but rather it can challenge the prognostic significance of these rearrangements. © 2018, Holder Demo
Nonlinear interaction of light with Bose-Einstein condensate: new methods to generate subpoissonian light
We consider -type model of the Bose-Einstein condensate of sodium
atoms interacting with the light. Coefficients of the Kerr-nonlinearity in the
condensate can achieve large and negative values providing the possibility for
effective control of group velocity and dispersion of the probe pulse. We find
a regime when the observation of the "slow" and "fast" light propagating
without absorption becomes achievable due to strong nonlinearity. An effective
two-level quantum model of the system is derived and studied based on the su(2)
polynomial deformation approach. We propose an efficient way for generation of
subpoissonian fields in the Bose-Einstein condensate at time-scales much
shorter than the characteristic decay time in the system. We show that the
quantum properties of the probe pulse can be controlled in BEC by the classical
coupling field.Comment: 13 pages, 6 figures, 1 tabl
Tetraquarks and Pentaquarks in String Models
We consider the production and decay of multiquark systems in the framework
of string models where the hadron structure is determined by valence quarks
together with string junctions. We show that the low mass multiquark resonances
can be very narrow.Comment: 7 pages, 2 figure
Interaction of non-profit organizations and state structures of the region in the field of adaptive physical culture
The features of the provision of services by state organizations, non-profit organizations within the framework of project activities and grant support in the field of adaptive physical culture and sports are revealed. Based on the results of the analysis of the involvement of non-profit organizations (NPOs) and socially oriented non-profit organizations (SO NPOs) in the scheme of interaction with government agencies, their effectiveness in providing services (works) to the population in the field of adaptive physical culture and sports, a scheme of interaction was developed and proposed to solve the identified problem
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