• 제목/요약/키워드: HST

검색결과 197건 처리시간 0.026초

Heat-stress 온도 적용이 교감신경활동에 미치는 영향 (Influence of Heat Stress Temperature on Sympathetic Nerve Activities)

  • 임영은;양은영;김태열
    • 대한임상전기생리학회지
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    • 제5권2호
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    • pp.11-21
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    • 2007
  • The purpose of this study were to investigate influence of heat stress temperature on sympathetic nerve activities. Subjects were 8 normal adults (4 men, 4 women, 21.36 years old). First sympathetic nerve activities were measured at the point that increase of core temperature stops at the state of applying normal thermic temperature (NIT; $34^{\circ}C$). After measurement, temperature of bathtub was increased to heat stress temperature (HST; $46^{\circ}C$) and sympathetic nerve activities were remeasured at the point that temperature increase stops. Sympathetic skin response (SSR) were analyzed using EMG, IR thermometer, and auto stethoscope. SSR latency showed significant differences at both palms by electrical stimulation to median nerve (p<.05). Electrical stimulation to forehead showed significant difference at left palm (p<.05) and electrical stimulation to navel showed significant difference at right palm (p<.05). Median nerve in changes of SSR amplitude showed significant differences at both palms in HST (p<.01). Electrical stimulation to navel showed significant difference at left palm (p<.05). Ts of forehead and xiphoid process showed significant differences (p<0.01). Tc of oral (p<0.05) and inner ear (p<0.01) showed significant differences. Pulse rate showed significant difference (<0.05). This study showed that immersion in HST had significant decrease of excitability in sympathetic nervous system compared to immersion in NTT.

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A Study of Globular Cluster Systems in the Coma, Fornax, and Virgo Clusters of Galaxies from HST ACS and WFC3/IR Imaging

  • Cho, Hyejeon
    • 천문학회보
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    • 제42권1호
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    • pp.29.1-29.1
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    • 2017
  • I present new near-infrared (NIR) photometry of globular cluster (GC) systems associated to a cD galaxy NGC 4874 in the core of the Coma cluster and 16 early-type galaxies in the Fornax and Virgo clusters of galaxies using the Infrared Channel of the Wide Field Camera 3 (WFC3/IR) on board the Hubble Space Telescope (HST). Combining these high-resolution NIR data with new HST Advanced Camera for Surveys (ACS) optical photometry for NGC 4874 and existing ACS GC catalogs from the ACS Fornax and Virgo Cluster Surveys, I have examined for the first time the GC systems in a statistically significant optical/NIR sample of galaxies spanning a wide range of luminosities and colors. A primary goal of this study is to explore empirically whether the distributions of purely optical and hybrid optical - NIR color indices for extragalactic GCs have different forms and whether the relations between these color indices are nonlinear, indicating that they behave differently with underlying metallicity. I find that some GC systems of large galaxies in our sample show color bimodalities that differ between the optical and optical - NIR colors, in the sense that they have disparate ratios of "blue" and "red" peak GCs, as well as differing ratios in their color dispersions. Consistent with these results, I find empirically that the dependence of hybrid optical-NIR color on purely optical color is nonlinear, with an inflection at intermediate metallicities. These findings underscore the importance of understanding the nature of galaxy-to-galaxy variations in the GC color distributions and color-color relations, as well as the exact forms of the color-metallicity transformations, in interpreting the observational data on GC color bimodality. Our ACS data for NGC 4874 shows that its GC system exhibits a very strong blue tilt, implying a very steep mass-metallicity scaling, and the centroid of this GC system is offset by $4{\pm}1kpc$ from the luminosity center of NGC 4874, in the direction of NGC 4872. Finally, I discuss the asymmetrical GC distribution around a dwarf elliptical galaxy in Coma that has a very high relative velocity with respect to the cluster mean at small clustercentric radius.

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An effect of thermo-stimulation of lower abdomen on autonomic nervous system: An experimental study

  • Kim, Kyeong Han;Kim, Jong Uk;Kim, Bo Hyun;Shin, Jin Hyeon;Hong, Seong Jin;Lee, Sang Ryong;Yook, Tae-han
    • 대한약침학회지
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    • 제21권2호
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    • pp.98-103
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    • 2018
  • Objective: DIt is need to evaluate he changes of the bio-signals through the hot-cold stimulation in the CV4. Methods: The 30 healthy participants were enrolled and randomly allocated, to one of three groups(10 participants for each group): the hot stone therapy(HST) group, or the cold stone therapy(CST) group or no treatment group(NT). All the participants took a rest for 10 minutes for stability before the test. And additional 10 minute rest after measurements of skin test and sEMG. After that two group received hot or cold stone therapy for 30 minutes and one group treated nothing with HRV test. Results: HRV LF value showed a significant increase over time in all three groups, but there was no significant difference between groups but HRV HF value did not show any significant difference with time in all three groups and there was no significant difference between groups. sEMG value showed a significant increase in the left side of the masseter muscle of the HST group and sebum levels was a significant decreased in HST group but no significant meaning was found. Conclusion: There was no objective evidence that hot-cold stimulation produced bio-signals changes in comparison to the control group, but additional studies are needed as the subjects were limited.

X-Ray, UV and Optical Observations of Classical Cepheids: New Insights into Cepheid Evolution, and the Heating and Dynamics of Their Atmospheres

  • Engle, Scott G.;Guinan, Edward F.
    • Journal of Astronomy and Space Sciences
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    • 제29권2호
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    • pp.181-189
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    • 2012
  • To broaden the understanding of classical Cepheid structure, evolution and atmospheres, we have extended our continuing secret lives of Cepheids program by obtaining XMM/Chandra X-ray observations, and Hubble space telescope (HST) / cosmic origins spectrograph (COS) FUV-UV spectra of the bright, nearby Cepheids Polaris, ${\delta}$ Cep and ${\beta}$ Dor. Previous studies made with the international ultraviolet explorer (IUE) showed a limited number of UV emission lines in Cepheids. The well-known problem presented by scattered light contamination in IUE spectra for bright stars, along with the excellent sensitivity & resolution combination offered by HST/COS, motivated this study, and the spectra obtained were much more rich and complex than we had ever anticipated. Numerous emission lines, indicating $10^4$ K up to ${\sim}3{\times}10^5$ K plasmas, have been observed, showing Cepheids to have complex, dynamic outer atmospheres that also vary with the photospheric pulsation period. The FUV line emissions peak in the phase range ${\varphi}{\approx}0.8-1.0$ and vary by factors as large as $10{\times}$. A more complete picture of Cepheid outer atmospheres is accomplished when the HST/COS results are combined with X-ray observations that we have obtained of the same stars with XMM-Newton & Chandra. The Cepheids detected to date have X-ray luminosities of log $L_X{\approx}28.5-29.1$ ergs/sec, and plasma temperatures in the $2-8{\times}106$ K range. Given the phase-timing of the enhanced emissions, the most plausible explanation is the formation of a pulsation-induced shocks that excite (and heat) the atmospheric plasmas surrounding the photosphere. A pulsation-driven ${\alpha}^2$ equivalent dynamo mechanism is also a viable and interesting alternative. However, the tight phase-space of enhanced emission (peaking near 0.8-1.0 ${\varphi}$) favor the shock heating mechanism hypothesis.

IDENTIFICATION OF LUMINOUS WHITE DWARF CANDIDATES IN THE GLOBULAR CLUSTERS M13 AND M22 USING HST ACS PHOTOMETRIC DATA

  • CHO, DONG-HWAN;YOON, TAE SEOG;LEE, SANG-GAK;SUNG, HYUN-IL
    • 천문학논총
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    • 제30권2호
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    • pp.265-266
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    • 2015
  • A search for luminous white dwarfs (WDs) in several nearby Galactic globular clusters (GCs) was carried out using the deep and homogeneous photometric catalog of Galactic GCs taken with the ACS/WFC aboard the Hubble Space Telescope (HST) by Sarajedini et al. and Anderson et al- It resulted in the identification of luminous WD candidates in the GCs M13 (NGC 6205) and M22 (NGC 6656). The purpose of the present study is to identify luminous WDs in the deep and homogeneous V versus V - I color-magnitude diagrams (CMDs) of several nearby Galactic GCs taken with the ACS/WFC aboard the HST. Using photometric data for the GCs M13 and M22 that are now in the public domain, the V versus V - I CMDs of the GCs M13 and M22 were constructed. Many spurious detections in the CMDs were removed using the photometric quality parameters qfit(V) and qfit(I), and a radial restriction was applied to the CMDs to remove the central stars with higher photometric errors due to central crowding. From each resultant V versus V - I CMD of the GCs M13 and M22, a dozen or so luminous WD candidates were identified. They were confirmed as stellar objects in the accompanying ACS/WFC images and their positions in the CMDs were in the bright part of the DA WD cooling curve. Therefore, the luminous WD candidates in the GCs M13 and M22 seem to be true luminous WDs, and spectroscopic observations are needed to confirm their true identity.

2급 응급구조사 병원임상실습교육 효과 비교 (Comparison of Effectiveness on Hospital-based Skill Training in Level 2 Emergency Medical Technician)

  • 김동옥
    • 한국화재소방학회논문지
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    • 제28권5호
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    • pp.104-109
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    • 2014
  • 본 연구는 2급 응급구조사 병원임상실습교육의 효과와 만족도를 조사한 연구로써 2급 응급구조사 전문화 교육의 만족도를 높이고, 효과적으로 운영하기 위한 기초자료를 제공하는데 목적이 있다. 조사대상은 2013년 7월 29일부터 8월 22일까지 2급 응급구조사 병원임상실습교육에 참여한 70명의 2급 응급구조사로 하였으며 구조화된 무기명 자기기입식 설문지를 이용하여 조사하였다. 연구결과 대상자가 자가평가한 업무능력은 교육 전이 3.09점, 교육 후 3.73점으로 유의한 차이를 보였고, 교육만족도는 3.80점으로 나타났다. 대상자들이 생각하는 교육적정기간은 1주~2주가 64.3%였고, 2급 응급구조사 자격과정을 오래전에 수료했을수록 교육만족도가 높았다. 향후 2급 응급구조사 병원임상실습교육의 요구도, 문제점 등을 파악하기 위한 다각적인 연구가 필요하며, 수련을 담당하는 의료기관의 실습교육 모니터링을 포함하는 프로그램의 개발이 필요하다.