• Title/Summary/Keyword: Network Activity

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A SEARCH FOR AGN INTRA-DAY VARIABILITY WITH KVN

  • LEE, TAESEOK;TRIPPE, SASCHA;OH, JUNGHWAN;BYUN, DO-YOUNG;SOHN, BONG-WON;LEE, SANG-SUNG
    • Journal of The Korean Astronomical Society
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    • v.48 no.5
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    • pp.313-323
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    • 2015
  • Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a “anti-correlated” mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ~1.6% to ~7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.

Flux Variation and Structural Change in 3C 84 with Long-Term Monitoring by KVN and KaVA at Millimeter Wavelengths

  • Wajima, Kiyoaki;Kino, Motoki;Kawakatu, Nozomu
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.45.2-46
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    • 2017
  • 3C 84 (NGC 1275) is one of the most famous radio galaxies and a lot of VLBI observations have been conducted to date because of its brightness and proximity (z = 0.0176; 1 mas = 0.36 pc). The source is entering a significantly active phase with long-term increase in radio flux at cm wavelengths since 2005, and the increased activity at very-high-energy (VHE) gamma rays. In order to study properties of sub-pc-scale structure and the circumnuclear environment in 3C 84, we have conducted multi-epoch VLBI observations with the Korean VLBI Network (KVN) at 86 and 129 GHz, and monthly monitoring by the KVN and VERA Array (KaVA) at 43 GHz from 2015 August. Following the report in the previous KAS meeting (cf. 2016 KAS Autumn Annual Meeting, [구 GC-10]), we present further results mainly on the basis of twelve-epoch observations with KaVA at 43 GHz. Through the monthly monitoring with KaVA, we found that peak intensity of the pc-scale southern lobe (C3) was increased from $2.60\;Jy\;beam^{-1}$ in 2015 October to $9.80\;Jy\;beam^{-1}$ in 2016 June, corresponding to a flux increase of 3.7 times in eight months. We also detected change in direction of motion of C3 from transversal to outward with respect to C1, concurrently with the beginning of its flux increase in 2015 October. We consider that these phenomena are due to interaction of C3 with the ambient medium, and are related to the gamma-ray flare which has been detected with VHE gamma-ray telescopes such as MAGIC and VERITAS.

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The Father's Role and Father-Child Interaction: A Review of Literature (아버지-아동관계에 관한 이론적 고찰 - 아버지의 역할 및 아버지-아동의 상호작용을 중심으로 -)

  • Wui, Yeong Hee
    • Korean Journal of Child Studies
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    • v.4
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    • pp.23-35
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    • 1983
  • The purpose of this study is to systematize the theory of the father-child relationship by analyzing the father's role and father-child interaction. The results of this study are as followings: (1) The oedipal period 3 to 5 years is a critical in development of the father-child relationship. Father absence is assumed in infancy but it is denying because the father participates in Child- rearing activity. (2) The Father's role is symbolized instrumental role traditionally and culturally but it is appropriate that we think the father's role to be androgynous concepts. Instrumental role as well as expressive role is expected to father's role. (3) The role of the father is supplementary mother's role. The father provides economic, emotional support and helps the balanced child- rearing. This indirect role of the father is very important. (4) The father influences child development, and his role is to be sex-role model to contrieve personality internalize moral development. But it is needed more empirical study to clarify father's effects on child development. (5) The amount of time that fathers spend with their children is less than mothers, but it is not assumed that difference of this amount of time do not differently influence to the children. (6) There are much similarity that difference between father-child interaction and mother- child interaction. Qualitative difference in interaction is response style. A responsive style of the father is physical intellectual instructive but mother's is verbal. (7) The effects of the father to a child must be analyzed on dyadic dimension and triadic dimension of family network. In triadic dimension, father influences mother- child relationship, mother to response sensitively, husband-wife relation.

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Why Do People Move to Cohousing Communities in Sweden? - Are there any Significant Differences Between the +40 Cohousing and the Mixed-Age Cohousing?

  • Choi, Jung Shin
    • Architectural research
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    • v.15 no.2
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    • pp.77-86
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    • 2013
  • Cohousing is based on collaborative network, or fictive kin in the community. It could facilitate the goal of self-sufficiency. This research aims to investigate the motivation of move to cohousing communities in Sweden, and to find out if there are any significant differences according to two different cohousing types; between the +40 cohousing and the mixed-age cohousing. The +40 cohousing is a kind of senior cohousing in which residents are supposed to be aged over 40. Questionnaire survey was applied and 242 collected data were analyzed by SPSS statistical program. Notable differences in demographic and dwelling variables are found between the 2 groups. There are more women, singles, academics, and small dwellings in the +40 cohousing than in the mixed-age cohousing. Referring motivation of move, "sharing common activity" and "idea of cohousing" are commonly noticed as the main reasons why people move to cohousing communities. Major difference between the 2 groups is that residents of the +40 cohousing tend to stress more on social interaction with neighbors than practical merit. On the contrary, ones of the mixed-age cohousing focus more on practical advantage than social interaction. As a conclusion, it is evident that motivation of move to cohousing communities is different by cohousing types, which have different residents' characteristics. Cohousing could contribute to elevate marginal group's quality of life as an alternative living environment. Therefore, cohousing design has to be tailored to adapt residents' specific needs of different life-stages. In order to implement cohousing model into other countries, for instance into Korea, it needs to experiment with the notion of transplanting selected cohousing principles to a public housing development. In the mixed-age cohousing where more dual income families with young children than conventional housing developments reside, residents would need more practical advantage than emotional support in the community, while as residents in the senior cohousing need vice versa.

Induced Abortion and Breast Cancer: Results from a Population-Based Case Control Study in China

  • Wu, Jun-Qing;Li, Yu-Yan;Ren, Jing-Chao;Zhao, Rui;Zhou, Ying;Gao, Er-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3635-3640
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    • 2014
  • Aim: To determine whether induced abortion (IA) increases breast cancer (BC) risk. Materials and Methods: A population-based case-control study was performed from Dec, 2000 to November, 2004 in Shanghai, China, where IA could be verified through the family planning network and client medical records. Structured questionnaires were completed by 1,517 cases with primary invasive epithelial breast cancer and 1,573 controls frequency-matched to cases for age group. The information was supplemented and verified by the family planning records. Statistical analysis was conducted with SAS 9.0. Results: After adjusting for potential confounders, induced abortions were not found to be associated with breast cancer with OR=0.94 (95%CI= 0.79-1.11). Compared to parous women without induced abortion, parous women with 3 or more times induced abortion (OR=0.66, 95%CI=0.46 to 0.95) and women with 3 or more times induced abortion after the first live birth (OR=0.66, 95%CI =0.45 to 0.97) showed a lower risk of breast cancer, after adjustment for age, level of education, annual income per capita, age at menarche, menopause, parity times, spontaneous abortion, age at first live birth, breast-feeding, oral contraceptives, hormones drug, breast disease, BMI, drinking alcohol, drinking tea, taking vitamin/calcium tablet, physical activity, vocation, history of breast cancer, eating the bean. Conclusions: The results suggest that a history of induced abortions may not increase the risk of breast cancer.

Development of Information Strategy Planning Supporting Template for IMS (IMS를 위한 정보화 전략계획 수립지원 Template 개발)

  • 최병욱;이영수;장석호;윤취영
    • Proceedings of the CALSEC Conference
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    • 2002.01a
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    • pp.107-131
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    • 2002
  • Recently, it is an important problem that combines part of sale, technical development etc.. as well as function that is the multi-item and small quantity production environment and production to computer network that supports synthetic efficiency of general corporation activity in manufacturing industry. Integration production information system is developed by these requests and globalization of production system and marketing by tough international competition of various industry product need IMS(Intelligent Manufacturing System) that cope in these change. Therefore, this paper searches analysis method, problem and development way for information system of manufacture field to construct this IMS efficiently, and develops each information strategy planning establishment step, product and integral way of products which is the systematic establishment way of essential information strategy planning in efficient manufacturing information system construction. Also, this paper presents detailed system design methods of each step and templates for efficient methodology of information strategy planning to support IMS efficiently.

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p38 Kinase Regulates Nitric Oxide-induced Dedifferentiation and Cyclooxygenase-2 Expression of Articular Chondrocytes

  • Yu, Seon-Mi;Cheong, Seon-Woo;Cho, Sam-Rae;Kim, Song-Ja
    • IMMUNE NETWORK
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    • v.6 no.3
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    • pp.117-122
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    • 2006
  • Background: Caveolin, a family of integral membrane proteins are a principal component of caveolae membranes. In this study, we investigated the effect of p38 kinase on differentiation and on inflammatory responses in sodium nitroprusside (SNP)-treated chondrocytes. Methods: Rabbit articular chondrocytes were prepared from cartilage slices of 2-week-old New Zealand white rabbits by enzymatic digestion. SNP was used as a nitric oxide (NO) donor. In this experiments measuring SNP dose response, primary chondrocytes were treated with various concentrations of SNP for 24h. The time course of the SNP response was determined by incubating cells with 1mM SNP for the indicated time period $(0{\sim}24h)$. The cyclooxygenase-2 (COX-2) and type II collagen expression levels were determined by immunoblot analysis, and prostaglandin $E_2\;(PGE_2)$ assay was used to measure the COX-2 activity. The tyrosine phosphorylation of caveolin-1 was determined by immunoblot analysis and immunostaining. Results: SNP treatment stimulated tyrosine phosphorylation of caveolin-1 and activation of p38 kinase. SNP additionally caused dedifferentiation and inflammatory response. We showed previously that SNP treatment stimulated activation of p38 kinase and ERK-1/-2. Inhibition of p38 kinase with SB203580 reduced caveolin-1 tyrosine phosphorylation and COX-2 expression but enhanced dedifferentiation, whereas inhibition of ERK with PD98059 did not affect caveolin-1 tyrosine phosphorylation levels, suggesting that ERK at least is not related to dedifferentiation and COX-2 expression through caveolin-1 tyrosine phosphorylation. Conclusion: Our results indicate that SNP in articular chondrocytes stimulates dedifferentiation and inflammatory response via p38 kinase signaling in association with caveolin-1 phosphorylation.

Effect of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol on Immune Functions in Healthy Adults in a Randomized Controlled Trial

  • Hwang, Hee-Jin;Sohn, Ki-Young;Han, Yong-Hae;Chong, Saeho;Yoon, Sun Young;Kim, Young-Jun;Jeong, Jinseoun;Kim, Sang-Hwan;Kim, Jae Wha
    • IMMUNE NETWORK
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    • v.15 no.3
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    • pp.150-160
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    • 2015
  • We previously reported that 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) accelerates hematopoiesis and has an improving effect on animal disease models such as sepsis and asthma. The effects of PLAG supplementation on immune modulation were assessed in healthy men and women. The objective was to evaluate the effects of PLAG supplementation on immune regulatory functions such as activities of immune cells and cytokine production. A randomized double blind placebo-controlled trial was conducted. Seventy-five participants were assigned to one of two groups; all participants had an appropriate number of white blood cells on the testing day. The PLAG group (n=27) received oral PLAG supplements and the control group (n=22) received oral soybean oil supplements. IL-4 and IL-6 production by peripheral blood mononuclear cells (PBMC) were lower (p<0.001 and p<0.001, respectively) with PLAG than with soybean oil. However, the production of IL-2 and IFN-$\gamma$ by PBMC was unaltered with PLAG supplementation. The B cell proliferation decreased significantly in the PLAG group compared to the soybean oil control (p<0.05). The intake of PLAG in healthy adults for 4 weeks was deemed safe. These data suggest that PLAG has an immunomodulatory function that inhibits the excessive immune activity of immunological disorders such as atopic and autoimmune diseases. PLAG could improve the condition of these diseases safely as a health food supplement.

Alloferon Alleviates Dextran Sulfate Sodium-induced Colitis

  • Kim, Hyemin;Im, Jong Pil;Kim, Joo Sung;Kang, Jae Seung;Lee, Wang Jae
    • IMMUNE NETWORK
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    • v.15 no.3
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    • pp.135-141
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    • 2015
  • Dysfunction of gut immune regulation is involved in mucosal damage in inflammatory bowel disease (IBD). However, there is still no efficacious immune-regulator for the treatment of IBD. Alloferon is a novel immune-modulatory peptide that was originally isolated from infected insects. It shows anti-inflammatory effects by the regulation of cytokine production by immune cells and their activities. Therefore, we investigated the effect of alloferon in a mouse model of colitis using dextran sulfate sodium (DSS). Colitis was induced by administration of DSS in drinking water for 7 consecutive days. It was confirmed by the presence of weight loss, diarrhea, hematochezia, and colon contraction. Alloferon was injected 4 days after DSS administration. We found that alloferon improved the pathogenesis of IBD based on the reduced disease activity index (DAI) and colon contraction. Edema, epithelial erosion, and immune cell infiltration were found in mice administered DSS, but the phenomena were reduced following alloferon treatment. The plasma level of IL-6, a classical pro-inflammatory cytokine in colitis, was also decreased by alloferon. Moreover, alloferon inhibited the TNF-${\alpha}$-induced degradation and phosphorylation of $I{\kappa}B$ in Colo205 colon cancer cells. Taken together, these results show that alloferon has anti-inflammatory effects and attenuates DSS-induced colitis.

Enhancement of Proliferation and Antigen Presentation of Human B Cells in Vitro by K562 Cells Expressing CD40L (CD40L 발현 K562 세포주를 이용한 시험관내 B 세포 증식과 항원제공능 증가)

  • Park, Jung-Yong;Yoon, Sung-Hee;Kim, Eun-Kyung;Yun, Sun-Ok;Sohn, Hyun-Jung;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • v.7 no.2
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    • pp.80-86
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    • 2007
  • Background: CD40-activated B (CD40-B) cells might be an attractive source of autologous antigen-presenting cells (APCs) for immunotherapy due to the convenience to obtain from peripheral blood and expand in vitro. Moreover, CD40-B cells were found to be comparable with DCs in their capacity to raise antigen-specific CD8+ T cells. Here, we have established K562 cells expressing CD40L to expand CD40-activated B cells used for APCs. Methods: After activation of B cell by K562/CD40L, CD40-B cells were examined by counting B cell numbers. Surface expression of CD54, CD80, CD86 and HLA class II was measured by flow cytometry. The CD40-B cells were tested for its function as APC by mixed lymphocyte reactions (MLR) and by induction of T cell responses specific for pp65 peptide in vitro. Results: The expansion of B cells by K562/CD40L increased about 6-folds compared with anti-CD40 or K562. Furthermore, the expression of CD54, CD80, CD86 and HLA class II was up-regulated by K562/CD40L. B cells by K562/CD40L showed comparable antigen presentation activity with mature DCs as shown in MLR, INF-${\gamma}$ ELISPOT assay. Conclusion: These results suggest that K562/CD40L could be used to generate activated B cells as potent APCs which could be useful for cellular vaccination and adoptive immunotherapy.