• 제목/요약/키워드: Cluster Formation

검색결과 549건 처리시간 0.031초

N-Acetyl-D-Glucosamine Kinase Is a Component of Nuclear Speckles and Paraspeckles

  • Sharif, Syeda Ridita;Lee, HyunSook;Islam, Md. Ariful;Seog, Dae-Hyun;Moon, Il Soo
    • Molecules and Cells
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    • 제38권5호
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    • pp.402-408
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    • 2015
  • Protein O-GlcNAcylation, dictated by cellular UDP-N-acetylglucosamine (UDP-GlcNAc) levels, plays a crucial role in posttranslational modifications. The enzyme GlcNAc kinase (NAGK, E.C. 2.7.1.59) catalyzes the formation of GlcNAc-6-phosphate, which is a major substrate for the biosynthesis of UDP-GlcNAc. Recent studies have revealed the expression of NAGK in different types of cells especially in neuronal dendrites. Here, by immunocytochemistry (ICC) and immunonucleochemistry (INC) of cultured rat hippocampal neurons, HEK293T and GT1-7 cells, we have showed that NAGK immuno-reactive punctae being present in the nucleoplasm colocalized with small nuclear ribonucleoprotein-associated protein N (snRNPN) and p54NRB, which are speckle and paraspeckle markers, respectively. Furthermore, NAGK IR cluster was also found to be colocalized with GTF2H5 (general transcription factor IIH, polypeptide 5) immuno reactive punctae. In addition, relative localization to the ring of nuclear lamin matrix and to GlcNAc, which is highly enriched in nuclear pore complexes, showed that NAGK surrounds the nucleus at the cytoplasmic face of the nuclear outer membrane. By in situ proximity ligation assay (PLA) we confirmed the colocalization of NAGK with snRNPN in the nucleus and in dendrites, while we also verified the interactions of NAGK with p54NRB, and with GTF2H5 in the nucleus. These associations between NAGK with speckle, paraspeckle and general transcription factor suggest its regulatory roles in gene expression.

관찰자의 의복태도가 의복착용자의 인상에 미치는 영향 (The Effect of Perceiver's Attitude on Male Impressions.)

  • 남미우;강혜원
    • 한국의류학회지
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    • 제20권2호
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    • pp.241-256
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    • 1996
  • The purposee of this study was to identify the effect of perceiver's clothing attitude on male impressions created by the clothing cues and contexts. In addition, the effect of perceiver's evaluations of clothing appropriateness on male impressions. The subjects consisted of 256 male undergraduate students and 256 middle aged men. The experimental materials developed for this study were a set of stimuli and response scales. The stimuli were 8 color Photographs of drawings of a male figure in clothing which were minipulated in two levels, each of three clothing cues including type, style and color. The experimental design was full factorial design of 2(contexts$\times$clothing types$\times$clothing style$\times$clothing color). Each of the 16 sub-samples includes 16 subjects from the two perceiver group. Questionnaires used to measure perceivers responses to the stimuli were 7-point semantic differential scales composed of 37 bipolar adjectives representing personal traits. Four aspects of clothing attitude(fashion interest, status symbols consiousness, clothing conformity, practicality & comfort)were used to classify subjects into groups of 20 five-point likers type questionnaires adapted from the previous research. Clothing appropriateness were developed 5 point likest scales for evaluation of a stimulus person in each context. The data was processed by factor analysis, ANOVA, multiple classification analysis, Duncan's multiple range test, cluster analysis, MANOVA and pearson's product moment correlations. The major findings drawn from this study were as follows: 1. Perceiver's clothing attitude influenced impression formed by the social contexts and clothing crises. In three groups classified by their clothing attitude, the status symbol-oriented group was most affected by the social contexts and clothing cues. 2. Perceiver's evaluation of clothing appropriateness was related with impressions by a stimulus person. In summary the effect of contexts and clothing cues on impression formation varied according to perceiver's clothing attitude and clothing approopiateness.

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하천 내 수질 개선을 위한 박층류 하도의 적용 및 평가 (Application and Evaluation of the Sheet Flow Channel for Water Quality Improvement in the Stream)

  • 이두한;김명환;구정은;김원
    • Ecology and Resilient Infrastructure
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    • 제6권4호
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    • pp.208-216
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    • 2019
  • 본 연구는 하천 내의 자연형 수질정화기법으로 박층류 하도의 설계방법과 효율에 대해서 연구하였다. 박층류 하도의 설계인자를 고려하여 설계를 수행하고 오산천 고수부지에 시험구간을 조성하여 모니터링을 수행하였다. 수위, 유속, 유량, T-N, T-P, NO3-N 등에 대한 모니터링 결과를 이용하여 제거효율을 평가하고 설계식을 제시하였다. T-N, T-P, NO3-N 등의 제거효율은 10 - 20%로 나타났으며 체류시간과 일정한 관계를 나타내고 있다. 또한 조류 형성과 유속 간의 관계를 통해 최소 유속 조건을 제시하였다. 본 연구에서 제시된 체류시간과 제거효율의 관계식은 차집수로 설계와 운영에 유용할 것으로 기대된다.

SH 2-128, AN H II AND STAR FORMING REGION IN AN UNLIKELY PLACE

  • BOHIGAS JOAQUIN;TAPIA MAURICIO
    • 천문학회지
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    • 제37권4호
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    • pp.285-288
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    • 2004
  • Near-infrared imaging photometry supplemented by optical spectroscopy and narrow-band imaging of the H II region Sh 2-128 and its environment are presented. This region contains a developed H II region and the neighboring compact H II region S 128N associated with a pair of water maser sources. Midway between these, the core of a CO cloud is located. The principal ionizing source of Sh 2-128 is an 07 star close to its center. A new spectroscopic distance of 9.4 kpc is derived, very similar to the kinematic distance to the nebula. This implies a galactocentric distance of 13.5 kpc and z = 550 pc. The region is optically thin with abundances close to those predicted by galactocentric gradients. The $JHK_s$ images show that S 128N contains several infrared point sources and nebular emission knots with large near-infrared excesses. One of the three red Ks knots coincides with the compact H II region. A few of the infrared-excess objects are close to known mid- and far-infrared emission peaks. Star counts in J and $K_s$ show the presence of a small cluster of B-type stars, mainly associated with S 128N. The $JHK_s$ photometric properties together with the characteristics of the other objects in the vicinity suggest that Sh 2-128 and S 128N constitute a single complex formed from the same molecular cloud, with ages ${\~}10^6$ and < $3 {\times} 10^5$ years respectively. No molecular hydrogen emission was detected at 2.12 ${\mu}m$. The origin of this remote star forming region is an open problem.

The Effect of Ethanol on the Physical Properties of Neuronal Membranes

  • Bae, Moon-Kyoung;Jeong, Dong-Keun;Park, No-Soo;Lee, Cheol-Ho;Cho, Bong-Hye;Jang, Hye-Ock;Yun, Il
    • Molecules and Cells
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    • 제19권3호
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    • pp.356-364
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    • 2005
  • Intramolecular excimer formation of 1,3-di(1-pyrenyl) propane(Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to evaluate the effect of ethanol on the rate and range of lateral and rotational mobilities of bulk bilayer structures of synaptosomal plasma membrane vesicles (SPMVs) from the bovine cerebral cortex. Ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMVs. Selective quenching of both DPH and Py-3-Py by trinitrophenyl groups was used to examine the range of transbilayer asymmetric rotational mobility and the rate and range of transbilayer asymmetric lateral mobility of SPMVs. Ethanol increased the rotational and lateral mobility of the outer monolayer more than of the inner one. Thus ethanol has a selective fluidizing effect within the transbilayer domains of the SPMVs. Radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py was used to examine both the effect of ethanol on annular lipid fluidity and protein distribution in the SPMVs. Ethanol increased annular lipid fluidity and also caused membrane proteins to cluster. These effects on neuronal membranes may be responsible for some, though not all, of the general anesthetic actions of ethanol.

무선 센서 네트워크에서 효율적인 에너지 사용을 위한 클러스터링 알고리즘 (Clustering Algorithm for Efficient Energy Consumption in Wireless Sensor Networks)

  • 나성원;최승권;이태우;조용환
    • 한국컴퓨터정보학회논문지
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    • 제19권6호
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    • pp.49-59
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    • 2014
  • 최근 무선 센서 네트워크(WSN)이 침입 탐지와 생태, 환경, 대기, 산업, 교통, 화재 감시 등에 다양하게 적용되어 사용되고 있다. 본 논문에서는 에너지 효율적인 클러스터링 알고리즘을 제안한다. 제안 알고리즘은 수신전력을 바탕으로 하여 최적위치의 클러스터헤드를 선출하고 이를 통해 균일한 클러스터사이즈를 가지도록 한다. 또한 최대 깊이가 제한된 MST를 이용한 라우팅 트리를 구성하고 멀티 홉 전송을 통해 센서 노드의 위치에 관계없이 균일한 에너지 소모를 유도하도록 하였다. 이를 통해 제안 알고리즘은 기존의 LEACH나 HEED에 비해 노드의 에너지 소모를 감소시키고 균등한 에너지 소모를 유도하여 네트워크 수명을 증대시킬 수 있다. 시뮬레이션 결과 제안 알고리즘이 공평한 에너지 소모를 통해 네트워크 수명을 증대시킬 수 있음을 확인하였다.

고투자율, 고포화자화 FeZrBAg 연자성 박막의 자기적 특성 (Magnetic Properties of FeZrBAg Soft Magnetic Thin Films with High Permeability and High Magnetization)

  • 민복기;김현식;송재성
    • 한국자기학회지
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    • 제9권6호
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    • pp.285-290
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    • 1999
  • 고투자율 및 고포화자화 특성을 동시에 만족하는 새로운 연자성 박막을 개발하기 위해 Fe-Zr-B계 조성에 Fe원소와 비고용 원소인 Ag를 첨가시킨 Fe86.7Zr3.3B4Ag6 비정질 박막을 DC 마그네트론 스퍼터링법으로 제조한 후 일축 자장중에서 1시간 동안 진공 열처리를 한 후 fan을 이용하여 냉각하여 특성을 조사하였다. Fe86.7Zr3.3B4Ag6 박막을 40$0^{\circ}C$에서 열처리한 후 1.7T의 높은 포화자화와 1 Oe의 낮은 보자력으로 인해 50 MHz에서 투자율이 7,800(0.2 mOe)으로 우수한 연자기 특성을 나타내었으며, 1 MHz에서 손실이 1.4 W/cc(B=0.1T)로 매우 낮았다. 이러한 고주파 연자기 특성은 Ag 첨가에 의해 비정질 기지에 미세한 bcc $\alpha$-Fe cluster가 균일하게 형성되었기 때문이라 생각된다.

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Preparation and Pore-Characteristics Control of Nano-Porous Materials using Organometallic Building Blocks

  • Oh, Gyu-Hwan;Park, Chong-Rae
    • Carbon letters
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    • 제4권1호
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    • pp.1-9
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    • 2003
  • Recently, the control of pore-characteristics of nano-porous materials has been studied extensively because of their unique applications, which includes size-selective separation, gas adsorption/storage, heterogeneous catalysis, etc. The most widely adopted techniques for controlling pore characteristics include the utilization of pillar effect by metal oxide and of templates such as zeolites. More recently, coordination polymers constructed by transition metal ions and bridging organic ligands have afforded new types of nano-porous materials, porous metal-organic framework(porous MOF), with high degree and uniformity of porosity. The pore characteristics of these porous MOFs can be designed by controlling the coordination number and geometry of selected metal, e.g transition metal and rare-earth metal, and the size, rigidity, and coordination site of ligand. The synthesis of porous MOF by the assembly of metal ions with di-, tri-, and poly-topic N-bound organic linkers such as 4,4'-bipyridine(BPY) or multidentate linkers such as carboxylates, which allow for the formation of more rigid frameworks due to their ability to aggregate metal ions into M-O-C cluster, have been reported. Other porous MOF from co-ligand system or the ligand with both C-O and C-N type linkage can afford to control the shape and size of pores. Furthermore, for the rigidity and thermal stability of porous MOF, ring-type ligand such as porphyrin derivatives and ligands with ability of secondary bonding such as hydrogen and ionic bonding have been studied.

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양성자 조사된 폴리아크릴로니트릴 필름의 광학적 특성 (Optical Properties of Proton-irradiated Polyacrylonitrile Film)

  • 이화수;백가영;정진묵;황인태;정찬희;신준화;최재학
    • 방사선산업학회지
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    • 제10권1호
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    • pp.1-5
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    • 2016
  • In this study, the effect of high-energy proton irradiation on the optical properties of polyacrylonitrile (PAN) films was investigated. PAN thin films spin-coated on a substrate were irradiated 150 keV proton ions at various fluences. The changes in the chemical structure and optical properties were investigated by FT-IR and UV-vis spectroscopy. The results of the FT-IR analysis revealed that the cyclization reaction took place by proton irradiation and the degree of cyclization increased with an increasing fluence. Based on the UV-vis analysis, the optical band gap of PAN decreased from 2.84 to 2.52 eV with an increasing fluence due to the formation of carbon clusters by proton irradiation. In addition, the number of carbon atoms per carbon cluster and the number of carbon atoms per conjugation length were found to be increased with an increasing fluence.

A deep and High-resolution Study of Ultra-diffuse Galaxies in Distant Massive Galaxy Clusters

  • Lee, Jeong Hwan;Kang, Jisu;Jang, In Sung;Lee, Myung Gyoon
    • 천문학회보
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    • 제44권1호
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    • pp.38.4-38.4
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    • 2019
  • Ultra-diffuse galaxies (UDGs) are intriguing in the sense that they are much larger than dwarf galaxies but have much lower surface brightness than normal galaxies. To date, UDGs have been found only in the local universe. Taking advantage of deep and high-resolution HST images, we search for UDGs in massive galaxy clusters in the distant universe. In this work, we present our search results of UDGs in three massive clusters of the Hubble Frontier Fields: Abell 2744 (z=0.308), Abell S1063 (z=0.348), and Abell 370 (z=0.375). These clusters are the most distant and massive among the host systems of known UDGs. The color-magnitude diagrams of these clusters show that UDGs are mainly located in the faint end of the red sequence. This means that most UDGs in these clusters consist of old stars. Interestingly, we found a few blue UDGs, which implies that they had recent star formation. The radial number densities of UDGs clearly decrease in the central region of the clusters in contrast to those of bright galaxies which keep rising. This implies that a large fraction of UDGs in the central region were tidally disrupted. These features are consistent with those of UDGs in nearby galaxy clusters. We estimate the total number of UDGs (N(UDG)) in each cluster. The abundance of UDGs shows a tight relation with the virial masses (M_200) of thier host systems: M_200 \propto N(UDG)^(1.01+/-0.05). This slope is found to be very close to one, indicating that efficiency of UDGs does not significantly depend on the host environments. Furthermore, estimation of dynamical masses of UDGs indicates that most UDGs have dwarf-like masses (M_200 < 10^11 M_Sun), but a few UDGs have $L{\ast}$-like masses (M_200 > 10^11 M_Sun). In summary, UDGs in distant massive clusters are found to be similar to those in the local universe.

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