144 research outputs found

    Star Formation Activity Beyond the Outer Arm II: Distribution and Properties of Star Formation

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    The outer Galaxy beyond the Outer Arm represents a promising opportunity to study star formation in an environment vastly different from the solar neighborhood. In our previous study, we identified 788 candidate star-forming regions in the outer Galaxy (at galactocentric radii RGR_{\rm G} ≥\ge 13.5 kpc) based on Wide-field Infrared Survey Explorer (WISE) mid-infrared (MIR) all-sky survey. In this paper, we investigate the statistical properties of the candidates and their parental molecular clouds derived from the Five College Radio Astronomy Observatory (FCRAO) CO survey. We show that the molecular clouds with candidates have a shallower slope of cloud mass function, a larger fraction of clouds bound by self-gravity, and a larger density than the molecular clouds without candidates. To investigate the star formation efficiency (SFE) at different RGR_{\rm G}, we used two parameters: 1) the fraction of molecular clouds with candidates and 2) the monochromatic MIR luminosities of candidates per parental molecular cloud mass. We did not find any clear correlation between SFE parameters and RGR_{\rm G} at RGR_{\rm G} of 13.5 kpc to 20.0 kpc, suggesting that the SFE is independent of environmental parameters such as metallicity and gas surface density, which vary considerably with RGR_{\rm G}. Previous studies reported that the SFE per year (SFE/yr) derived from the star-formation rate surface density per total gas surface density, HI plus H2_2, decreases with increased RGR_{\rm G}. Our results might suggest that the decreasing trend is due to a decrease in HI gas conversion to H2_2 gas.Comment: 40 pages, 26 figures, 5 tables, accepted for publication in Ap

    Three-dimensional Assessment of Femoral Head Coverage in Normal and Dysplastic Hips: A Novel Method

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    The acetabular coverage of the femoral head has been assessed in two-dimensions as the projected covered area or the covered angle on plain radiographs. We present a novel method of the three-dimensional assessment of femoral head coverage obtained by evaluating the covered volume of the femoral head in both normal and dysplastic hips. We also assessed the covered angles on the vertical slices passing through the center of the femoral head. The mean covered volume of the femoral head was 57.4% in normal hips and 26.6% in dysplastic hips. In dysplastic hips, the L-CE, A-CE, and P-CE angles were 7.7°, 21.8°, and 95.8°, respectively, while the acetabular angle was 27.5°. In normal hips, the CE angles were 34.0°, 56.8°, and 109.4°, respectively, while the acetabular angle was 7.2°. Our study suggests the usefulness of a novel 3D assessment for acetabular coverage of the femoral head. This assessment provided the precise 3D information necessary to diagnose hip dysplasia and assess the deficiency of acetabular coverage in these patients. Moreover, we may detect a cut-off between normal and dysplastic hips in the 3D assessment by assessing a large number of dysplastic hips both morphologically and using the new assessment

    Quantized Anomalous Hall Effect in Two-Dimensional Ferromagnets - Quantum Hall Effect from Metal -

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    We study the effect of disorder on the anomalous Hall effect (AHE) in two-dimensional ferromagnets. The topological nature of AHE leads to the integer quantum Hall effect from a metal, i.e., the quantization of σxy\sigma_{xy} induced by the localization except for the few extended states carrying Chern number. Extensive numerical study on a model reveals that Pruisken's two-parameter scaling theory holds even when the system has no gap with the overlapping multibands and without the uniform magnetic field. Therefore the condition for the quantized AHE is given only by the Hall conductivity σxy\sigma_{xy} without the quantum correction, i.e., ∣σxy∣>e2/(2h)|\sigma_{xy}| > e^2/(2h).Comment: 5 pages, 4 figures, REVTe

    Relationship between the Hip Abductor Muscles and Abduction Strength in Patients with Hip Osteoarthritis

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    This study aimed to determine which muscle the gluteus maximus, gluteus medius, gluteus minimus (Gmin), or tensor fasciae latae (TFL) contributes most to hip abduction strength and to identify effective sites for cross-sectional area (CSA) Gmin and TFL measurement in hip osteoarthritis (OAhip) patients. Twenty-eight patients with OAhip were included. The muscle CSA and volume were determined using magnetic resonance imaging. Peak isometric strength was determined using hand-held dynamometry. Muscle volumes were normalized to the total muscle volume of hip abductors. Multiple regression analysis was performed. The difference between the CSA of Gmin and TFL was calculated, and correlations with volume and muscle strength were determined. Gmin volume was related to abductor muscle strength (p=0.042). The peak CSA of the Gmin correlated with muscle volume and strength. The CSA of the TFL correlated with volume, with no difference between the CSA of the most protruding part of the lesser trochanter and peak CSA. Gmin volume was strongly related to abductor muscle strength. Peak CSA is a useful parameter for assessing the CSA of the Gmin among patients with OAhip. The CSA of the TFL should be measured at the most protruding part of the lesser trochanter
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