• Journal of Trauma and Injury
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• v.33 no.4
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• pp.227-235
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• 2020

Purpose: Alcohol intoxication is commonly associated with traumatic brain injury (TBI), but the influence of alcohol on the Glasgow Coma Scale (GCS) score remains unclear. This study investigates the effects of blood alcohol concentration (BAC) on the GCS score in head trauma patients with alcohol intoxication. Methods: In total, 369 head trauma patients with alcohol intoxication in a 1-year period were retrospectively analyzed. The patients underwent head computed tomography and had a BAC ≥80 mg/dL. Patients were divided into TBI and non-TBI groups. Brain injury severity was further classified using the head Abbreviated Injury Score (AIS). The effects according to 5 BAC groups were examined. Results: The TBI group consisted of 64 patients (16.2%). The mean BAC was significantly higher in the non-TBI group (293.4±87.3 mg/dL) than in the TBI group (242.8±89.9 mg/dL). The mean GCS score was significantly lower in the TBI group (10.3±4.6) than in the non-TBI group (13.0±2.5). A higher BAC showed a significant association with a lower mean GCS score in the TBI group, but not in the non-TBI group. Above ≥150 mg/dL, higher BACs showed significant odds ratios for a lower GCS score. Conclusions: The influence of alcohol in patients with head trauma depended on the presence of a brain injury. An association between a higher BAC and a lower GCS score was only observed in patients with TBI. Therefore, if a severe brain injury is suspected based on a GCS evaluation in patients with alcohol intoxication, prompt diagnosis and intensive care should be performed without delay.

• Animal cells and systems
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• v.6 no.3
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• pp.247-252
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• 2002

The effect of paraquat (PQ, 1,1＇-dimethyl-4,4＇-bipyridium) on the histogene-sis and glycoconjugates (GCs) properties of the pyloric region of the stomach in a perinatal rat was examined by histological and histochemical methods. Oral administration of PQ (9 mg/kg per day in 0.2 mL of D.W.) on 7 to 14 days of gestation revealed growth retardation with significant reductions in the length of pyloric gland and their pit. As for histochemical properties of GCs in the pyloric region of the stomach, the PQ-treated rats showed some differences, such as delayed initial appearance of the sulfated GCs and lectin affinities compared with the vehicle group. These different GCs properties in the surface and gastric pit were usually detected in the fetal rats and more prominent and evident differences were revealed in the gland epithelium of the early postnatal rat. These results suggest that maternal PQ administration causes intrauterine growth retardation asso-ciated with delayed histogenesis and GCs immaturation of pyloric mucosa in developing rat.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.57.3-57.3
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• 2015

The formation of the Milky Way stellar halo is thought to be the result of merging and accretion of building blocks such as dwarf galaxies and massive globular clusters. Recently, Deason et al. (2015) suggested that the Milky Way outer halo formed mostly from big building blocks, such as dwarf spheroidal galaxies, based on the similar number ratio of blue straggler (BS) stars to blue horizontal-branch (BHB) stars. Here we demonstrate, however, that this result is seriously biased by not taking into detailed consideration on the formation mechanism of BHB stars from helium enhanced second-generation population. In particular, the high BS-to-BHB ratio observed in the outer halo fields is most likely due to a small number of BHB stars provided by GCs rather than to a large number of BS stars. This is supported by our dynamical evolution model of GCs which shows preferential removal of first generation stars in GCs. Moreover, there are sufficient number of outer halo GCs which show very high BS-to-BHB ratio. Therefore, the BS-to-BHB number ratio is not a good indicator to use in arguing that more massive dwarf galaxies are the main building blocks of the Milky Way outer halo. Several lines of evidence still suggest that GCs can contribute a signicant fraction of the outer halo stars.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.33.3-34
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• 2015

We present the spectroscopic study of the globular clusters (GCs) in the massive elliptical galaxy M86 in the Virgo galaxy cluster. Using the spectra obtained from the Multi-Object Spectroscopy (MOS) mode of Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope, we measure the radial velocities for 56 GCs in M86. The mean velocity of the GCs is derived to be $<v_p>=-335{\pm}41km/s$, which is different from the velocity of the M86 nucleus ($<v_{gal}>=-224{\pm}5km/s$) within ${\sim}2.5{\sigma}$. The mean velocity ($<v_p>=-342{\pm}60km/s$) of 33 blue GCs in M86 is similar to that ($<v_p>=-314{\pm}71km/s$) of 23 red GCs. We also derive the mean velocities of the GC systems in other 16 nearby early-type galaxies (ETGs) from the radial velocity data in the literature. The mean value of the differences between the mean velocity of the GC systems in each galaxy and the nucleus velocity of their host galaxies, is almost zero except the M86 GC system. But the scatter of the differences in the blue GC system is larger than that in the red GC system. We will discuss these results in the context of GC formation in ETGs.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.33.2-33.2
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• 2015

The color distribution functions (CDFs) of globular clusters (GCs) in individual early-type galaxies show great diversity in their morphology. Based on the conventional "linear" relationship between colors and metallicities of GCs, the inferred GC metallicity distribution functions and thus their formation histories should be as diverse as they appear. In contrast, an alternative scenario rooted in the "nonlinear" nature of the color-to-metallicity transformation finds the various CDFs pointing systematically to a simple picture, i.e., such a high degree of variety stems predominately from only one parameter, the mean metallicity of GCs. The simulated CDFs of GCs aimed to reproduce 67 massive early-type galaxies from the ACS Virgo & Fornax Cluster Survey show that over 70% of the CDFs concur fully with the nonlinearity scenario. We discuss our new findings in terms of early-type galaxy formation in the cluster environment.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.74.2-74.2
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• 2013

Recent spectroscopic observations have provided evidences for the multiple stellar populations having different abundances in some massive globular clusters (GCs). In particular, some of these GCs show clear separations of red giant-branches (RGBs) in calcium narrow band photometry. In order to confirm the differences in heavy element abundances and radial velocities among multiple RGBs, we have performed the low-resolution spectroscopy for the RGB stars in these GCs. The spectral data were taken from the multi-object spectroscopic mode with WFCCD mounted on the du Pont 2.5m telescope in Las Campanas Observatory. In this talk, we will present our progress in the spectroscopic analysis of the RGB stars in these GCs.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.74.1-74.1
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• 2013

We have performed new narrow-band calcium photometry for Milky Way globular clusters (GCs) and detected multiple red giant branches (RGBs) in some massive GCs. Our new calcium filter was designed to avoid the CN contamination below $3883{\AA}$ and to measure only Ca II H&K lines. The fact that we are detecting multiple RGBs from the new filter is suggesting that they are indeed different in calcium abundance, which can only be produced by supernovae (SNe). Therefore, the presence of the multiple RGBs for the peculiar GCs in the calcium photometry is best understood if the later generation of stars are enhanced in some SNe products. In this talk, we will present our progress in the calcium photometry for the peculiar GCs showing the multiple RGBs.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.77.4-78
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• 2017

The presence of double red clump (RC; metal-rich counterpart of horizontal-branch) in high latitude field of the Milky Way (MW) bulge is widely interpreted as evidence for an X-shaped structure originated from the bar instability. However, Lee et al. (2015) recently suggested an alternative model, according to which the double RC is metal-rich manifestation of multiple stellar population phenomenon observed in globular clusters (GCs). Here we show that stars in bright RC are enhanced in CN compared to those in faint RC from our low-resolution spectroscopy. CN traces N, and N-rich stars are also enhanced in Na and He in GCs. Since GCs are the only environment that produce second generation stars with enhanced N, Na, & He, this is a direct evidence that stars in the classical bulge component of the MW were mostly provided by proto-GCs.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.81.2-81.2
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• 2010

Based on Yonsei Evolutionary Population Synthesis (YEPS), we have investigated the effect of horizontal branch stars (HBs) on the age-dating of simple stellar populations (SSPs). A detailed comparison of YEPS SSP with H_beta of M31 globular clusters (GCs) reveals (1) that the age dating without HB prescription gives ~5 Gyr younger ages for metal-poor M31 GCs, and (2) the age dating with HB prescription does not need any age gap between metal-poor and metal-rich GCs. This result is parallel to the well-known discrepancy in ages derived from integrated Balmer strengths and isochrone fittings of Milky Way GCs (MWGCs). Without a synthetic blue HB model, we cannot explain strong Balmer indices of metal-poor and old MWGCs. Our results suggest that the SSP model with well calibrated HBs should be used for the age-dating of SSPs to avoid a serious underestimation of ages due to the strong Balmer indices.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.62.2-62.2
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• 2020

Globular clusters(GCs) are found not only around galaxies (galaxy GCs), but also between galaxies in galaxy clusters (intracluster GCs; ICGCs). The ICGCs, which are not bound to any of cluster member galaxies, are governed by the galaxy clutster potential. ICGCs have been detected in the wide field of Virgo and Fornax galaxy clusters. However, previous surveys covered only a small fraction of Coma and Perseus. In this study we present a wide field survey of these two galaxy clusters, using Subaru Hyper Suprime-Cam(HSC) archival images, covering a circular field with diameter of ~1.8 deg. We select ICGC candidates, by masking the images of bright galaxies and choosing point sources in the remaining area. We find thousands of ICGCs in each galaxy cluster. These ICGCs show a bimodal color distribution, which is dominated by blue GCs. We investigate spatial distributions and radial number density profiles of the blue and red ICGCs in each galaxy cluster. Implications of the results will be discussed.