628 research outputs found

    Structure of the Milky Way stellar halo out to its outer boundary with blue horizontal-branch stars

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    We present the structure of the Milky Way stellar halo beyond Galactocentric distances of r=50r = 50 kpc traced by blue horizontal-branch (BHB) stars, which are extracted from the survey data in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). We select BHB candidates based on (g,r,i,z)(g,r,i,z) photometry, where the zz-band is on the Paschen series and the colors that involve the zz-band are sensitive to surface gravity. About 450 BHB candidates are identified between r=50r = 50 kpc and 300 kpc, most of which are beyond the reach of previous large surveys including the Sloan Digital Sky Survey. We find that the global structure of the stellar halo in this range has substructures, which are especially remarkable in the GAMA15H and XMM-LSS fields in the HSC-SSP. We find that the stellar halo can be fitted to a single power-law density profile with an index of α3.3\alpha \simeq 3.3 (3.53.5) with (without) these fields and its global axial ratio is q2.2q \simeq 2.2 (1.31.3). Thus, the stellar halo may be significantly disturbed and be made in a prolate form by halo substructures, perhaps associated with the Sagittarius stream in its extension beyond r100r \sim 100 kpc. For a broken power-law model allowing different power-law indices inside/outside a break radius, we obtain a steep power-law slope of α5\alpha \sim 5 outside a break radius of 100\simeq 100 kpc (200200 kpc) for the case with (without) GAMA15H and XMM-LSS. This radius of 200200 kpc might be as close as a halo boundary if there is any, although larger BHB sample is required from further HSC-SSP survey to increase its statistical significance.Comment: 12 pages, 8 figures, revised version, accepted for publication in PAS

    The impact of bar origin and morphology on stellar migration

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    Different mechanisms driving bar structure formation indicate that bar origins should be distinguishable in the stellar populations of galaxies. To study how these origins affect different bar morphologies and impact stellar orbits and migration, we analyse three simulated discs which are representative of bar formation under isolated evolution motivated by disc instability, and interaction driven tidal development. The first isolated disc and the tidally driven disc produce similar bar structure, while the second isolated disc, generated by the tidal initial condition without the companion, is visibly dissimilar. Changes to radial and vertical positions, angular momentum in the disc-plane, orbital eccentricity and the subsequent disc metallicities are assessed, as is the dependence on stellar age and formation radii. Bar origin is distinguishable, with the tidal disc displaying larger migration overall, higher metallicity difference between the inner and outer disc, as well as a population of inner disc stars displaced to large radii and below the disc-plane. The affect of closest approach on populations of stars formed before, after and during this period is evident. However, bar morphology is also found to be a significant factor in the evolution of disc stellar properties, with similar bars producing similar traits in migration tendency with radius, particularly in vertical stellar motion and in the evolution of central metallicity features

    Association between Oral Health Status and Diabetic Nephropathy-Related Indices in Japanese Middle-Aged Men

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    Oral health status is known to be associated with lifestyle-related diseases such as diabetes and chronic kidney disease. In Japan, around 40% of hemodialysis cases are patients with diabetic nephropathy. The aim of this study was to clarify the association between oral health status and diabetic nephropathy-related indices in Japanese middle-aged men. Sixty-six men (age range: 55–64 years) with ≥20 remaining teeth and who received public medical checkups and oral examinations were enrolled. We examined correlations of age, body mass index, HbA1c, HDL-C, LDL-C, neutral fat, serum creatinine, and the estimated glomerular filtration rate (eGFR) with the number of remaining teeth or the community periodontal index (CPI) score (periodontal pocket < 4mm: 0, 4–6 mm: 1, ≥6 mm: 2). A positive correlation between the CPI score and serum creatinine and a negative correlation between CPI score and eGFR (Spearman’s rank correlation coefficient, r = 0.459, p < 0.01, and r = −0.460, p < 0.01, respectively) were observed. The mean eGFR in the CPI score 0 group was significantly higher than that in the CPI score 1/2 group (82.6 vs. 70.7, Student’s t-test, p < 0.01). Logistic regression analysis using eGFR as a dependent variable and age, CPI score, body mass index, HbA1c, and neutral fat as independent variables suggested that low eGFR (<60) could be attributed to CPI score (OR = 3.169, 95% CI: 1.031–9.742, p = 0.044). These results suggest a possible association between periodontal status and renal function in Japanese middle-aged men. Periodontal condition is controlled by oral prophylaxis, and periodontal disease and chronic kidney disease have some common risk factors. Thus, periodontal management can contribute to the prevention of severe chronic kidney disease

    A Case of Intestinal Obstruction in Pregnancy Diagnosed by MRI and Treated by Intravenous Hyperalimentation

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    Intestinal obstruction in pregnancy is rare and is mainly caused by prior pelvic surgery. We herein report a case of intestinal obstruction in a pregnant female with a history of laparoscopic myomectomy, who presented with hypogastric pain, abdominal distension, and vomiting at 26 weeks of gestation. A simple intestinal obstruction was diagnosed by MRI. Conservative treatments, including intravenous hyperalimentation and the placement of an ileus tube, were provided and her abdominal symptoms improved for 14 days. After restarting oral intake, she had no abdominal symptoms. She gave birth to a 2,146 g female infant by caesarean section at 37 weeks and 1 day of gestation. Although an area of cicatrization, which was thought to have been the starting point of the occlusion that caused the intestinal obstruction, was found, the excision of the small intestine was not necessary. Her postoperative course was uneventful. Intestinal obstruction requires a prompt diagnosis and aggressive intervention may be necessary to minimize the morbidity and mortality associated with this rare complication of pregnancy. MRI can be safely used during pregnancy to diagnose intestinal obstruction and intravenous hyperalimentation may improve the maternal and fetal prognoses

    Searches for New Milky Way Satellites from the First Two Years of Data of the Subaru/Hyper Suprime-Cam Survey: Discovery of Cetus~III

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    We present the results from a search for new Milky Way (MW) satellites from the first two years of data from the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) 300\sim 300~deg2^2 and report the discovery of a highly compelling ultra-faint dwarf galaxy candidate in Cetus. This is the second ultra-faint dwarf we have discovered after Virgo~I reported in our previous paper. This satellite, Cetus~III, has been identified as a statistically significant (10.7σ\sigma) spatial overdensity of star-like objects, which are selected from a relevant isochrone filter designed for a metal-poor and old stellar population. This stellar system is located at a heliocentric distance of 25111+24^{+24}_{-11}~kpc with a most likely absolute magnitude of MV=2.4±0.6M_V = -2.4 \pm 0.6~mag estimated from a Monte Carlo analysis. Cetus~III is extended with a half-light radius of rh=9017+42r_h = 90^{+42}_{-17}~pc, suggesting that this is a faint dwarf satellite in the MW located beyond the detection limit of the Sloan Digital Sky Survey. Further spectroscopic studies are needed to assess the nature of this stellar system. We also revisit and update the parameters for Virgo~I finding MV=0.330.87+0.75M_V = -0.33^{+0.75}_{-0.87}~mag and rh=4713+19r_h = 47^{+19}_{-13}~pc. Using simulations of Λ\Lambda-dominated cold dark matter models, we predict that we should find one or two new MW satellites from 300\sim 300~deg2^2 HSC-SSP data, in rough agreement with the discovery rate so far. The further survey and completion of HSC-SSP over 1,400\sim 1,400~deg2^2 will provide robust insights into the missing satellites problem.Comment: 12 pages, 12 figures, accepted for publication in PASJ special issu

    Conditional deletion of Bmpr1a in differentiated osteoclasts increases osteoblastic bone formation, increasing volume of remodeling bone in mice

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    Bone undergoes remodeling consisting of osteoclastic bone resorption followed by osteoblastic bone formation throughout life. Although the effects of bone morphogenetic protein (BMP) signals on osteoblasts have been studied extensively, the function of BMP signals in osteoclasts has not been fully elucidated. To delineate the function of BMP signals in osteoclasts during bone remodeling, we deleted BMP receptor type IA ( Bmpr1a ) in an osteoclast‐specific manner using a knock‐in Cre mouse line to the cathepsin K locus ( Ctsk Cre/+ ;Bmpr1a flox/flox , designated as Bmpr1a ΔOc/ΔOc ). Cre was specifically expressed in multinucleated osteoclasts in vivo. Cre‐dependent deletion of the Bmpr1a gene occurred at 4 days after cultivation of bone marrow macrophages obtained from Bmpr1a ΔOc/ΔOc with RANKL. These results suggested that Bmpr1a was deleted after formation of osteoclasts in Bmpr1a ΔOc/ΔOc mice. Expression of bone‐resorption markers increased, thus suggesting that BMPRIA signaling negatively regulates osteoclast differentiation. Trabeculae in tibia and femurs were thickened in 3.5‐, 8‐, and 12‐week‐old Bmpr1a ΔOc/ΔOc mice. Bone histomorphometry revealed increased bone volume associated with increased osteoblastic bone‐formation rates (BFR) in the remodeling bone of the secondary spongiosa in Bmpr1a ΔOc/ΔOc tibias at 8 weeks of age. For comparison, we also induced an osteoblast‐specific deletion of Bmpr1a using Col1a1‐Cre. The resulting mice showed increased bone volume with marked decreases in BFR in tibias at 8 weeks of age. These results indicate that deletion of Bmpr1a in differentiated osteoclasts increases osteoblastic bone formation, thus suggesting that BMPR1A signaling in osteoclasts regulates coupling to osteoblasts by reducing bone‐formation activity during bone remodeling. © 2011 American Society for Bone and Mineral ResearchPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87086/1/477_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/87086/2/jbmr_477_sm_SupplData.pd
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