• 제목/요약/키워드: Sun:active regions

검색결과 68건 처리시간 0.03초

SEJONG OPEN CLUSTER SURVEY (SOS) - V. THE ACTIVE STAR FORMING REGION SH 2-255 - 257

  • LIM, BEOMDU;SUNG, HWANKYUNG;HUR, HYEONOH;LEE, BYEONG-CHEOL;BESSELL, MICHAEL S.;KIM, JINYOUNG S.;LEE, KANG HWAN;PARK, BYEONG-GON;JEONG, GWANGHUI
    • 천문학회지
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    • 제48권6호
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    • pp.343-355
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    • 2015
  • There is much observational evidence that active star formation is taking place in the Hii regions Sh 2-255 – 257. We present a photometric study of this star forming region (SFR) using imaging data obtained in passbands from the optical to the mid-infrared, in order to study the star formation process. A total of 218 members were identified using various selection criteria based on their observational properties. The SFR is reddened by at least E(B −V ) = 0.8 mag, and the reddening law toward the region is normal (RV = 3.1). From the zero-age main sequence fitting method it is confirmed that the SFR is 2.1 ± 0.3 kpc from the Sun. The median age of the identified members is estimated to be about 1.3 Myr from a comparison of the Hertzsprung-Russell diagram (HRD) with stellar evolutionary models. The initial mass function (IMF) is derived from the HRD and the near-infrared (J, J −H) color-magnitude diagram. The slope of the IMF is about Γ = −1.6 ± 0.1, which is slightly steeper than that of the Salpeter/Kroupa IMF. It implies that low-mass star formation is dominant in the SFR. The sum of the masses of all the identified members provides the lower limit of the cluster mass (169M). We also analyzed the spectral energy distribution (SED) of pre-main sequence stars using the SED fitting tool of Robitaille et al., and confirm that there is a significant discrepancy between stellar mass and age obtained from two different methods based on the SED fitting tool and the HRD.

Cloning and Functional Expression in Escherichia coli of the Polyhydroxyalkanoate Synthase (phaC) Gene from Alcaligenes sp. SH-69

  • Lee, Il;Nam, Sun-Woo;Rhee, Young-Ha;Kim, Jeong-Yoon
    • Journal of Microbiology and Biotechnology
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    • 제6권5호
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    • pp.309-314
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    • 1996
  • Alcaligenes sp. SH-69 can synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from a single carbon source such as glucose. To clone the phaC gene from Alcaligenes sp. SH-69, a polymerase chain reaction was performed using the oligomers synthesized based on the conserved regions of the phaC genes from other bacteria. A PCR product (550 bp) was partially sequenced and the deduced amino acid sequence was found to be homologous to that of the phaC gene from Alcaligenes eutrophus. Using the PCR fragment Southern blotting of Alcaligenes sp. SH-69 genomic DNA digested with several restriction enzymes was carried out. To prepare a partial genomic library, about 5-Kb genomic DNA fragments digested with EcoRI, which showed a positive signal in the Southern blotting, were eluted from an agarose gel, ligated with pUC19 cleaved with EcoRI, and transformed into Escherichia coli. The partial library was screened using the PCR fragment as a probe and a plasmid, named pPHA11, showing a strong hybridization signal was selected. Restriction mapping of the insert DNA in pPHA11 was performed. Cotransformation into E. coli of the plasmid pPHA11 and the plasmid pPHA21 which has phaA and phaB from A. eutrophus resulted in turbid E. coli colonies which are indicative of PHA accumulation. This result tells us that the Alcaligenes sp. SH-69 phaC gene in the pPHA11 is functionally active in E. coli and can synthesize PHA in the presence of the A. eutrophus phaA and phaB genes.

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Activated Phenoloxidase Interacts with A Novel Glycine-rich Protein on the Yeast Two-hybrid System

  • Lee, Sun-Woo;Lee, Hyun-Seong;Kim, Eun-Jun;Yoo, Mi-Ae;Lee, Bok-Luel
    • BMB Reports
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    • 제34권1호
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    • pp.15-20
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    • 2001
  • One of the innate immune reactions in invertebrates is the pro-phenoloxidase (pro-PO) activation system that is involved in the generation of superoxide, melanin synthesis, and the subsequent sequestration of foreign matter entering the hemocoel of the invertebrates. However, the molecular mechanism of this biological reaction is still obscure. To expand our understanding of the biological roles of the pro-PO activation system in invertebrates, we performed a yeast two-hybrid screening by using three regions of pro-PO as bait and a yeast two-hybrid cDNA library from Tenebrio molitor larvae as prey We isolated a novel partial cDNA clone that encodes a glycine-rich protein that interacted with the active phenoloxidase (termed phenoloxidase interacting protein, POIP). POIP consists of two domains: One is an N-terminal unique domain and the other is a C-terminal glycine-rich domain. The C-terminal glycine-rich domain showed sequential homology with those of insect antifungal proteins. Also, the yeast two-hybrid screen in a reverse orientation (using POIP as bait) yielded PO, suggesting that the PO-POIP interaction is specific. By using a 315 bP PCR fragment of the N-terminal unique region of POIP, we cloned the full-length cDNA of POIP from the Tenebruo cDNA library constructed by using E. coli injected larvae. The interaction analysis between PO, and a truncated fragment lacking the N-terminal unique region of POIP, indicated that the N-terminal unique region is necessary for interaction between PO and POIP. The expression level of the POIP mRNA is increased by bacterial injection into T. molitor larvae. This suggests that POIP might be engaged in the humoral defense reaction.

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구제역의 병리기전 및 진단, 예방백신 개발 (Pathogenesis, Dianosis, and Prophylactic Vaccine Development for Foot-and-Mouth Disease)

  • 문선화;양주성
    • Applied Biological Chemistry
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    • 제48권4호
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    • pp.301-310
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    • 2005
  • 구제역(Foot-and-Mouth Disease: FMD)이란 소, 돼지, 양, 염소 등의 cloven-hoofed 동물에서 나타나는 바이러스성 질병으로 입, 코, 유두, 발굽 등에 수포가 형성되는 것이 특징이다. 일곱 가지 혈청형(O, A, C, Asia1, SAT1, SAT2 and SAT3)으로 분류되는 구제역바이러스(Foot-and-Mouth Disease Virus: FMDV)는 single stranded positive RNA virus로 nonenveloped capsid virus이다. Viral genome은 8.2 Kb로 하나의 ORF인 polyprotein으로 되어있으며, 크게 capsid protein coding region인 P1, replication related protein coding region인 P2, RNA dependent RNA polymerase coding region인 P3로 구성된다. FMDV는 respiratory tract의 pharynx epithelial cell에 감염되며, lung epithelial cell에서 replication을 한다. 구제역바이러스는 감염율은 높지만 낮은 치사율을 가진다. 2002년 한국에서 구제역이 발병하여 많은 경제적 손실을 입었다. FMDV의 감염을 조절할 수 있는 조절방법이 없는 실정이며, 현재 많은 나라에서는 구제역바이러스의 감염을 막을 수 있는 효과적인 방법을 연구하고 있다. 본 보고서에서는 FMD에 대한 보다 효과적인 예방법인 DNA vaccine, edible vaccine, peptide vaccine에 대해 고찰하였다.

W UMa형 별들의 UV 방출선 연구 (UV LINE EMISSIONS OF W UMa STARS)

  • 김용기;한동주
    • Journal of Astronomy and Space Sciences
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    • 제17권1호
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    • pp.39-44
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    • 2000
  • lUE 저분산 자로플 가지고 44i Boo, W UMa, AW UMa및 VW Cep에서 나오는 자외선 방출선들의 특징을 조사하였다 단파장영역과 장파장영역에서의 방출선 선세기를 구하여, 이를 자$\boxUl$선 등급으로 변환하여 광도곡선을 얻었다 단파장 영ff에서 나오는 방출선인 C I, C II, C IV, SiIV, N V에 대한 선세기를 구한 결파, C IV가 모든 별에서 가장 센 방출을 보였으며. Si IV와 NV는 비교적 작은 양의 선세기를 나타내었다. 4개의 W UMa 별 쿵에근 44i Boo가 가장 높은 선세기를 보였으며, 단과장 영역에서는 위상 0.2와 0 8부근에서 자외선 팡도가 maximup을 보이는 변광을 확인하였다 또한, 전이영역에서 나오는 C IV, Si IV, N V 방출선을 합하여 이를 극소기의 태양값과 비교하여 태양보다 최대40배의 높은 활동성을 가지고 있음을 알았다. 짧은 주기를 갖는 별,즉 44i Boo, W UMa, AW UMa순으로 전이영역의 헐동성이 감소하는 것으로 나타났다. 장 파장 영역에서는 AW UMa와 VW Cep의 Mg ll 방출선을 조사하였는데, 단파장의 방출선 보다 뚜렷한 주기적 변광을 보였으며, 이를 이응하여 두 별의 유효온도를 추정하였다..

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In-situ and remote observation of Cochlodinium.p blooms and consequences of physical features off the Korean coast

  • Ahn Yu-Hwan;Shanmugam P.;Ryu Joo-Hyung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.553-556
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    • 2004
  • Spatial and temporal aspects of toxic dinoflagellate Cochlodinium.p blooms and consequences of physical features in complex coastal ecosystems, off the southern Korean coast, have been investigated using data obtained from SeaWiFS and AVHRR as well as in-situ observations. Hydrographic parameters measured using CTD sensors were used to elucidate physical factors affecting the spatial distribution and abundance of Cochlodinium.p blooms. The results show spatial and temporal variations of chlorophyll-a (Chl-a) and sea surface temperature (SST) and reveal significant information about Cochlodinium.p blooms and process underlying their evolution. Satellitederived Chl-a estimates appear to be potential in explicating the evolution, movement and distribution of Cochlodinium.p blooms in the enclosed bays of the South Sea. The existence of thromohaline waters offshore provide favorable conditions for the rapid growth and subsequent southward initiation of Cochlodinium.p blooms that are influenced to flow on the offshore branch (OB) during September. It was observed that there was a significant variation in the sun-induced chlorophyll-a fluorescence signal in the remote sensing fluorescence spectra and its high-intensity was recognized during the period of exponential growth and physical transport. Satellite-derived Chl-a concentration during September 1999 ranged between $3­60mg/m^3$ inside the Jin-hae and adjacent Bays and $1-6mg/m^3$ in offshore waters, with varying Cochlodinium.p abundances 1500 to 26000 cells $ml^{-1}.$ The closely spaced CTD surveys and satellite-derived SST give a complete overview on the initiation of Cochlodinium.p blooms in hydrodynamically active regions of the offshore southern East Sea by the influence of Tsushima Warm Current (TWC).

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NVST DATA ARCHIVING SYSTEM BASED ON FASTBIT NOSQL DATABASE

  • Liu, Ying-Bo;Wang, Feng;Ji, Kai-Fan;Deng, Hui;Dai, Wei;Liang, Bo
    • 천문학회지
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    • 제47권3호
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    • pp.115-122
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    • 2014
  • The New Vacuum Solar Telescope (NVST) is a 1-meter vacuum solar telescope that aims to observe the fine structures of active regions on the Sun. The main tasks of the NVST are high resolution imaging and spectral observations, including the measurements of the solar magnetic field. The NVST has been collecting more than 20 million FITS files since it began routine observations in 2012 and produces maximum observational records of 120 thousand files in a day. Given the large amount of files, the effective archiving and retrieval of files becomes a critical and urgent problem. In this study, we implement a new data archiving system for the NVST based on the Fastbit Not Only Structured Query Language (NoSQL) database. Comparing to the relational database (i.e., MySQL; My Structured Query Language), the Fastbit database manifests distinctive advantages on indexing and querying performance. In a large scale database of 40 million records, the multi-field combined query response time of Fastbit database is about 15 times faster and fully meets the requirements of the NVST. Our slestudy brings a new idea for massive astronomical data archiving and would contribute to the design of data management systems for other astronomical telescopes.

임산부의 의료기관 정보탐색과 성과 (Information Search for the Choice of Delivery Care Institution and Its Effects)

  • 권순호;한달선
    • 한국병원경영학회지
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    • 제3권1호
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    • pp.219-237
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    • 1998
  • Economists have identified informed consumer choice as one element of a better-functioning health care market, and thus increased attention is directed to the role of information in the health care system. In this country, however, little work has been done for understanding consumers' search behavior in health care market. Based upon this observation, expectant mothers' information search for the choice of delivery care institution was investigated. In doing so, two hypotheses were proposed: 1) Those women who were more active in the search for information would make choice of a delivery care institution with more confidence and would feel greater subsequent satisfaction. 2) The activeness of expectant mothers in information search would depend upon their various personal characteristics, such as socio-economic status, obstetric conditions, and knowledge and attitudes in relation to delivery and health care. The data used for the analysis were collected through face-to-face interviews with those women who had childbirth during the period from January 1, 1996 to the date of interview in February 1998. The survey was conducted using prepared structured questionnaire in Seoul. The sample was drawn from each of arbitrarily defined four regions of Seoul, Northeast, Northwest, Southeast and Southwest, in proportion to the number of births reported in 1996 in each of them. The distribution of the interviewed women by educational level was made similar to that of mothers of new babies reported in 1996. The sample size was planned to be about 300, but ended up with 319. The results of analysis were generally consistent with the proposed hypotheses. Apparently, information increased expectant mothers' confidence in selecting a delivery care institution and subsequent satisfaction with the institution. Indication is that policy efforts should be strengthened to produce and disseminate relevant, comprehensible and credible information that can aid patient decision making. Also, attention should be directed to motivate patients to actively engage in information search from adequate sources.

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Overexpression, Purification and Truncation Analysis of RmlC Protein of Mycobacterium tuberculosis

  • Lee, Jong-Seok;Lee, Tae-Yoon;Park, Jae-Ho;Kim, Jong-Sun;Lee, Tae-Jin;Lee, Jai-Youl;Kim, Sung-Kwang
    • 대한미생물학회지
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    • 제35권4호
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    • pp.273-282
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    • 2000
  • dTDP-rhamnose provides L-rhamnose to the bridge-like structure between mycolyl arabinogalactan and peptidoglycan of the mycobacterial cell wall. dTDP-rhamnose is composed of glucose-l-phosphate and dTTP by four enzymes encoded by rmlA-D. To determine the region(s) of RmlC protein essential for its dTDP-4-keto-6-deoxyglucose epimerase activity, we overexpressed both whole (202 amino acids) and three different truncated (N-terminal 106 or 150 or C-terminal 97 amino acids) RmlC proteins of Mycobacterium tuberculosis. The RmlC enzyme activity in the soluble lysates of ${\Delta}rmlC$ E. coli strain $S{\Phi}874$ (DE3 PlysS) expressing the wild type or truncated rmlC genes was initially analyzed by three sequential reactions from dTDP-glucose to dTDP-rhamnose in the presence of purified RmlB and RmlD. All three soluble lysates containing the truncated RmlC proteins showed no enzyme activity, while that containing the wild type RmlC was active. This wild type RmlC was then overexpressed and purified. The incubation of the purified RmlC enzyme so obtained with dTDP-4-keto-6-deoxyglucose resulted in the conversion of dTDP-4-keto-rhamnose. The results show that the truncated regions of the RmlC protein are important for the RmlC enzyme activity in M. tuberculosis.

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일부지역의 치위생학과 전공심화과정에 대한 개설 요구도 및 운영방안 (A demand for opening and a plan for operation on major deepening course for department of dental hygiene in some regions)

  • 한지형;정영란;정유선
    • 한국치위생학회지
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    • 제11권3호
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    • pp.363-372
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    • 2011
  • Objectives : The purpose of this study was to pursue an efficient operating plan by surveying the cognition and demand level for major deepening course. Methods : Questionnaire survey was carried out targeting 135 dental hygienists who work in Cheonan and neighboring region. The collected data was performed frequency & percentage, T-test and ANOVA analysis. Results : 1. As for dental hygienists' acquiring academic degree, 77.0% of them responded to have interest. As for a desired route of acquiring academic degree, the major deepening course or Credit Bank System was the highest with 62.2%. 2. As a result of surveying cognition on major deepening course, 73.3% responded to know. A route of having come to know was the largest in senior or friend with 34.8%. Necessity of major deepening course was responded to be necessary with 89.7%. 89.1% of them clarified to have intention of acquiring. 3. The curricular subject, which is desired to be learnt for a plan of operating major deepening course, was the highest in the major field with 63.0%. 4. As a result of comparing an interest, necessity, and intention of acquisition on major deepening course depending on general characteristics, the statistically significant difference wasn't shown. Conclusions : These results suggest that major deepening of course through active public should be aware that many dental hygienists will be subject to a variety of programs and development of clinical course and a practical hands-on education is expected to be strengthened.