1,449 research outputs found

    Dipole and Quadrupole Moments of Mirror Nuclei 8B and 8li

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    Magnetic dipole and electric quadrupole moments of the mirror nuclei 8Li and 8B are analysed in the framework of the multiparticle shell model by using two approaches : i) the one-particle spectroscopic factors and ii) the one-particle fractional parentage coefficients. These two approaches are compared both each to other and with a microscopic multicluster model. The one-particle nucleon states are calculated taking into account the continuum by the method of the expansion of the Sturm - Liouville functions. The experimental magnetic and quadrupole moments of 8Li and 8Bare reproduced well by using fractional parentage coefficients technique. The root mean-square radii and the radial density distributions are obtained for these nuclei.Comment: 20 pages 1 figur

    An Isobaric Model for Kaon photoproduction

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    The kaon photoproduction is analyzed up to EγLabE_\gamma^{\rm Lab}=2.0 GeV by using an isobaric model based on effective Lagrangians and by taking a cross symmetry into account. Both {\it pseudovector} and {\it pseudoscalar} couplings for kaon-baryon-baryon (baryon spin=1/2) interactions are considered with form factors. A vector meson(K(890)K^*(890)), an axial vector meson(K1(1270)K_1(1270)), nucleon resonances(J5/2J\le5/2), and hyperon resonances(J3/2J\le3/2) are treated as participating particles. By determining unknown coupling constants through a systematic fitting of the differential cross section, the total cross section, the single polarization observable, and the radiative kaon capture branching ratio to their experimental data, we find out a simple model which reproduces all the experimental data well.Comment: 48 pages, 7 figure

    Modeling bursts and heavy tails in human dynamics

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    Current models of human dynamics, used from risk assessment to communications, assume that human actions are randomly distributed in time and thus well approximated by Poisson processes. We provide direct evidence that for five human activity patterns the timing of individual human actions follow non-Poisson statistics, characterized by bursts of rapidly occurring events separated by long periods of inactivity. We show that the bursty nature of human behavior is a consequence of a decision based queuing process: when individuals execute tasks based on some perceived priority, the timing of the tasks will be heavy tailed, most tasks being rapidly executed, while a few experiencing very long waiting times. We discuss two queueing models that capture human activity. The first model assumes that there are no limitations on the number of tasks an individual can hadle at any time, predicting that the waiting time of the individual tasks follow a heavy tailed distribution with exponent alpha=3/2. The second model imposes limitations on the queue length, resulting in alpha=1. We provide empirical evidence supporting the relevance of these two models to human activity patterns. Finally, we discuss possible extension of the proposed queueing models and outline some future challenges in exploring the statistical mechanisms of human dynamics.Comment: RevTex, 19 pages, 8 figure

    Correlation between Ultrasonographic Findings and The Response to Corticosteroid Injection in Pes Anserinus Tendinobursitis Syndrome in Knee Osteoarthritis Patients

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    The objectives of this study were to assess the ultrasonographic (US) findings in patients with knee osteoarthritis (OA) with pes anserinus tendinitis or bursitis (PATB) syndrome and to determine the correlation between the US findings and the response to local corticosteroid injection. We prospectively studied 26 patients with knee OA with clinically diagnosed PATB syndrome. A linear array 7 MHz transducer was used for US examination of the knee. Seventeen patients were injected locally with tramcinolone acetonide in the anserine bursa area. Response to local corticosteroid injection was evaluated by pain visual analog scale (VAS), Western Ontario and MacMaster (WOMAC) osteoarthritis index and Global patient/physician assessment using Likert scale. On US examination, only 2 patients (8.7%) showed evidence of PATB. Pain VAS, WOMAC pain index and WOMAC physical function index improved significantly after corticosteroid injection. Global patient assessment revealed that 2 patients showed best response, 6 good, 1 fair, 8 the same, and none worse. It is of note that the 2 patients who showed the best response were those who showed US evidence of PATB. This finding shows that US can serve as a useful diagnostic tool for guiding treatment in PATB syndrome of OA patients

    Reliability of Eye Tracking and Pupillometry Measures in Individuals with Fragile X Syndrome

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    Recent insight into the underlying molecular and cellular mechanisms of fragile X syndrome (FXS) has led to the proposal and development of new pharmaceutical treatment strategies, and the initiation of clinical trials aimed at correcting core symptoms of the developmental disorder. Consequently, there is an urgent and critical need for outcome measures that are valid for quantifying specific symptoms of FXS and that are consistent across time. We used eye tracking to evaluate test–retest reliability of gaze and pupillometry measures in individuals with FXS and we demonstrate that these measures are viable options for assessing treatment-specific outcomes related to a core behavioral feature of the disorder

    Protein kinase B controls Mycobacterium tuberculosis growth via phosphorylation of the transcriptional regulator Lsr2 at threonine 112.

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    Mycobacterium tuberculosis (Mtb) is able to persist in the body through months of multi-drug therapy. Mycobacteria possess a wide range of regulatory proteins, including the protein kinase B (PknB) which controls peptidoglycan biosynthesis during growth. Here, we observed that depletion of PknB resulted in specific transcriptional changes that are likely caused by reduced phosphorylation of the H-NS-like regulator Lsr2 at threonine 112. The activity of PknB towards this phosphosite was confirmed with purified proteins, and this site was required for adaptation of Mtb to hypoxic conditions, and growth on solid media. Like H-NS, Lsr2 binds DNA in sequence-dependent and non-specific modes. PknB phosphorylation of Lsr2 reduced DNA binding, measured by fluorescence anisotropy and electrophoretic mobility shift assays, and our NMR structure of phosphomimetic T112D Lsr2 suggests that this may be due to increased dynamics of the DNA-binding domain. Conversely, the phosphoablative T112A Lsr2 had increased binding to certain DNA sites in ChIP-sequencing, and Mtb containing this variant showed transcriptional changes that correspond with the change in DNA binding. In summary, PknB controls Mtb growth and adaptations to the changing host environment by phosphorylating the global transcriptional regulator Lsr2

    Endoscopist Specialty Is Associated with High-Quality Endoscopy in Korea

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    Purpose: The present study was aimed to determine whether endoscopist specialty is associated with high-quality endoscopy. Materials and Methods: We prospectively collected endoscopy quality related data based on the Endoscopy Quality Rating Scale (EQRS) of 277 endoscopy units in a hospital setting from the National Cancer Screening Program of Korea in 2009. Gastroenterology medical professors (n=154) from university hospitals visited each endoscopy unit and graded the unit according to the EQRS. The scores from the EQRS were analyzed and compared in relation to endoscopy training during residency and endoscopy subspecialist certification. Results: After excluding data from 3 endoscopy units, EQRS data from 274 endoscopy units were analyzed: 263 esophagogastroduodenoscopy (EGD) screening units and 90 colonoscopy screening units. There were no significant differences in the scores of EQRS with respect to endoscopy training during residency (p=no significance), except for scores of EGDs for "Facility and Equipment" (p=0.030). However, EQRS scores were significantly higher in the endoscopy units where endoscopy subspecialists performed the endoscopies than those where Endoscopy Subspecialists did not perform the endoscopies (p<0.05, except p=0.08 for the "Process" criteria of EGD). Conclusion: Endoscopist specialty is an important determinant of high-quality endoscopy in Korea.This study was supported by a Grant-in-Aid for Cancer Research and Control from the National Cancer Center of Korea (#0960400-1)

    Continuation for thin film hydrodynamics and related scalar problems

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    This chapter illustrates how to apply continuation techniques in the analysis of a particular class of nonlinear kinetic equations that describe the time evolution through transport equations for a single scalar field like a densities or interface profiles of various types. We first systematically introduce these equations as gradient dynamics combining mass-conserving and nonmass-conserving fluxes followed by a discussion of nonvariational amendmends and a brief introduction to their analysis by numerical continuation. The approach is first applied to a number of common examples of variational equations, namely, Allen-Cahn- and Cahn-Hilliard-type equations including certain thin-film equations for partially wetting liquids on homogeneous and heterogeneous substrates as well as Swift-Hohenberg and Phase-Field-Crystal equations. Second we consider nonvariational examples as the Kuramoto-Sivashinsky equation, convective Allen-Cahn and Cahn-Hilliard equations and thin-film equations describing stationary sliding drops and a transversal front instability in a dip-coating. Through the different examples we illustrate how to employ the numerical tools provided by the packages auto07p and pde2path to determine steady, stationary and time-periodic solutions in one and two dimensions and the resulting bifurcation diagrams. The incorporation of boundary conditions and integral side conditions is also discussed as well as problem-specific implementation issues

    Zygosity diagnosis in young twins by parental report

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    this paper is twofold. First, the validity of zygosity classification across childhood is examined in a large sample. One might expect the physical dissimilarity between dizygotic twins to become more obvious as they grow up. If so, the accuracy of classification is likely to improve with increasing age of the participants. A few studies have reported on this issue by evaluating the precision of zygosity diagnosis between samples varying in age, 8,19,23 and by test--retest estimatio
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