68,864 research outputs found

    Are there socioeconomic gradients in stage and grade of breast cancer at diagnosis? Cross sectional analysis of UK cancer registry data

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    Socioeconomic gradients in uptake of breast cancer screening in the United Kingdom should, intuitively, lead to socioeconomic gradients in disease progression at diagnosis. However, studies have found little evidence of such an effect. Although this could be interpreted as evidence that socioeconomic gradients in uptake of screening do not have clinically important consequences, all of the published studies have used data from before (pre-1988) or during the early stages (1988-95) of implementation of the national breast cancer screening programme. We investigated the relation between socioeconomic position and progression of breast cancer at diagnosis by using recent data from the Northern and Yorkshire Cancer Registry and Information Service (NYCRIS), which is estimated to achieve around 93% ascertainment

    Parameters for Twisted Representations

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    The study of Hermitian forms on a real reductive group GG gives rise, in the unequal rank case, to a new class of Kazhdan-Lusztig-Vogan polynomials. These are associated with an outer automorphism δ\delta of GG, and are related to representations of the extended group . These polynomials were defined geometrically by Lusztig and Vogan in "Quasisplit Hecke Algebras and Symmetric Spaces", Duke Math. J. 163 (2014), 983--1034. In order to use their results to compute the polynomials, one needs to describe explicitly the extension of representations to the extended group. This paper analyzes these extensions, and thereby gives a complete algorithm for computing the polynomials. This algorithm is being implemented in the Atlas of Lie Groups and Representations software

    Nondestructive testing of brazed rocket engine components

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    Report details study made of nondestructive radiographic, ultrasonic, thermographic, and leak test methods used to inspect and evaluate the quality of the various brazed joints in liquid-propellant rocket engine components and assemblies. Descriptions of some of the unique equipment and methods developed are included

    Results on the nucleon spin structure

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    SMC performed an investigation of the spin structure of the nucleon by measuring deep inelastic scattering of polarised muons off polarised protons and deuterons. A summary of the results for spin structure functions and sum rules is given.Comment: 8 pages, LaTeX, Talk given at the Workshop on "Symmetry and Spin - PRAHA98", Prag, September 1998. Proceedings to be published by Czech. Journ. Phy

    The energy dependence of p_t angular correlations inferred from mean-p_t fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

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    We present the first study of the energy dependence of pt angular correlations inferred from event-wisemean transverse momentum (pt) fluctuations in heavy ion collisions. We compare our large-acceptancemeasurements at CM energies √^sNN = 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. p_t angular correlation structure suggests that the principal source of p_t correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with ln √^sNN from the onset of observable jet-related (p_t) fluctuations near 10 GeV

    Two-particle correlations on transverse momentum and momentum dissipation in Au–Au collisions at √sNN = 130 GeV

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    Measurements of two-particle correlations on transverse momentum p_t for Au–Au collisions at √^sNN = 130 GeV are presented. Significant largemomentum-scale correlations are observed for charged primary hadrons with 0.15 ≤ p_t ≤ 2 GeV/c and pseudorapidity |η| ≤ 1.3. Such correlations were not observed in a similar study at lower energy and are not predicted by theoretical collision models. Their direct relation to mean-p_t fluctuations measured in the same angular acceptance is demonstrated. Positive correlations are observed for pairs of particles which have large pt values while negative correlations occur for pairs in which one particle has large p_t and the other has much lower p_t . The correlation amplitudes per final state particle increase with collision centrality. The observed correlations are consistent with a scenario in which the transverse momentum of hadrons associated with initial-stage semi-hard parton scattering is dissipated by the medium to lower p_t

    High torque bellows seal rotary drive

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    Bellows seal rotary drive device was developed which allows high torque transmission through sealed compartments. Bearing friction which would normally be carried by sealing bellows in comparable devices is absorbed by universal-gimbal joint. It can be used to transmit high torque, low speed, rotary motion through sealed barriers to prevent contamination or escape of fluids

    The Growing Allocative Inefficiency of the U.S. Higher Education Sector

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    This paper presents new evidence on research and teaching productivity in universities. The findings are based on a panel that covers 1981-1999 and includes 102 top U.S. universities. Faculty size grows at 0.6 percent per year, compared with growth of 4.9 percent in the industrial science and engineering workforce. Measured by papers and citations per researcher, productivity grows at 1.4-6.7 percent per year and productivity and its rate of growth are higher in private than public universities. Measured by baccalaureate and graduate degrees per teacher, teaching productivity grows at 0.8-1.1 percent per year and growth is faster in public than private universities. A decomposition analysis shows that growth in research productivity within universities exceeds overall growth. This is because research shares grow more rapidly in universities whose productivity grows less rapidly. Likewise the research share of public universities increases even though productivity grows less rapidly in public universities. Together these findings suggest that allocative efficiency of U.S. higher education declined during the late 20th century. Regression analysis of individual universities finds that R&D stock, endowment, and postdoctoral students increase research productivity, that the effect of nonfederal R&D stock is less, and that research is subject to decreasing returns. Since the nonfederal R&D share grows and is much higher in public universities, this could account for some of the rising allocative inefficiency. The evidence for decreasing returns in research, which are greater than in teaching, suggests limits on the ability of more efficient institutions to expand and implies that differences in the scale of the teaching function are the primary reason for differences in university size. Besides all this the data strongly hint at growing financial pressures on U.S. public universities.
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