1,568 research outputs found

    Simultaneous dual-frequency radio observations of S5 0716+714: A search for intraday variability with the Korean VLBI Network

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    This study aims to search for the existence of intraday variability (IDV) of BL Lac object S5 0716+714 at high radio frequencies for which the interstellar scintillation effect is not significant. Using the 21-meter radio telescope of the Korean VLBI Network (KVN), we present results of multi-epoch simultaneous dual-frequency radio observations. Single-dish observations of S5 0716+714 were simultaneously conducted at 21.7 GHz (K-band) and 42.4 GHz (Q-band), with a high cadence of 30-60 minute intervals.We observed four epochs between December 2009 and June 2010. Over the whole set of observation epochs, S5 0716+714 showed significant inter-month variations in flux density at both the K- and Q-bands, with modulation indices of approximately 19% for the K-band and approximately 36% for the Q-band. In all epochs, no clear intraday variability was detected at either frequency. The source shows monotonic flux density increase in epochs 1 and 3 and monotonic flux density decrease in epochs 2 and 4. In the flux density increasing phases, the flux densities at the Q-band increase more rapidly. In the decreasing phase, no significant flux density difference is seen at the two frequencies. The situation could be different close to flux density peaks that we did not witness in our observations. We find an inverted spectrum with mean spectral indices of -0.57+-0.13 in epoch 1 and -0.15+-0.11 in epoch 3. On the other hand, we find relatively steep indices of +0.24+-0.14 and +0.17+-0.18 in epochs 2 and 4, respectively. We conclude that the frequency dependence of the variability and the change of the spectral index are caused by source-intrinsic effects rather than by any extrinsic scintillation effect.Comment: 6 pages and 4 figures and 4 table

    Synergistic Antibacterial Effect between Silibinin and Antibiotics in Oral Bacteria

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    Silibinin is a composition of the silymarin group as a hepatoprotective agent, and it exhibits various biological activities, including antibacterial activity. In this study, the antibacterial activities of silibinin were investigated in combination with two antimicrobial agents against oral bacteria. Silibinin was determined with MIC and MBC values ranging from 0.1 to 3.2 and 0.2 to 6.4 μg/mL, ampicillin from 0.125 to 64 and 0.5 to 64 μg/mL, gentamicin from 2 to 256 and 4 to 512 μg/mL, respectively. The ranges of MIC50 and MIC90 were 0.025–0.8 μg/mL and 0.1–3.2 μg/mL, respectively. The antibacterial activities of silibinin against oral bacteria were assessed using the checkerboard and time-kill methods to evaluate the synergistic effects of treatment with ampicillin or gentamicin. The results were evaluated showing that the combination effects of silibinin with antibiotics were synergistic (FIC index <0.5) against all tested oral bacteria. Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after 2–6 h of treatment with the MBC of silibinin, regardless of whether it was administered alone or with ampicillin or gentamicin. These results suggest that silibinin combined with other antibiotics may be microbiologically beneficial and not antagonistic

    Green with Envy at Your Kid: The Effects of Two Different Types of Envy on Purchase Intention

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    Envy is an emotion that “arises when a person lacks another’s superior quality, achievement, or possession and either desires it or wishes that the other lacked it”. Envy has been classified into two types: benign envy and malicious envy. Benign envy emphasizes the brighter side of envy, which is related to moving-up motivation, while malicious envy represents the destructive side of envy, which motivates people to pull down. The purpose of this study is to address research gap by exploring how envy affects purchase intention among mom through experimental design. Participants were recruited by research company, total one hundred and twenty eight moms with 5-7 year old kids were randomized in each study. Envy is manipulated into two types depending on the deservingness of the situation. Participants were given a short scenario which described a friend who has more capital for raising her children. In purchasing economic capital related products, benign envy condition(M=2.57, SD=1.36) reported greater desire for purchasing products than malicious envy condition(M=2.35, SD=1.21)(F=5.392, p\u3c.05). In purchasing cultural capital related products, benign envy condition(M=4.00, SD=0.78) reported greater desire for purchasing products than malicious envy condition(M=3.98, SD=1.08)(F=.235,n.s). The findings confirm that difference depending on type of envy, and benign envy play an important role for Koreans in purchase intention. In result, envy has no influence in purchasing cultural capital related products. It reveals that in Korea, fashion is used as a strategy of cultural capital, and sense of advanced taste are likely to be interpreted as part of cultural capital

    Data for Korean college students&apos; anxious and avoidant attachment, self-compassion, anxiety and depression

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    The data presented in this article are from 473 Korean college students׳ responses to an online survey consisting of measures of anxious and avoidant attachment (the Experiences in Close Relationships-Revised Scale: ECR-R), self-compassion (Neff׳s Self-Compassion Scale: SCS), depression (the Center for Epidemiological Studies-Depression Scale: CES-D) and anxiety (the State-Trait Anxiety Inventory-the Trait Anxiety Scale: STAT-T). Each variable was measured by a Korean version of the instrument. Participants were recruited from three universities in South Korea: 288 were men and 185 were women; 199 were undergraduate and 273 were graduate students. The online program used to collect the data prompted for but did not require responses to items; 26 surveys were not completed, and data from these surveys were not included in the dataset. Major findings based on the data presented here are reported in the article “Insecure attachment and emotional distress: Fear of self-compassion and self-compassion as mediators” (Joeng et al., 2017) [1]. The data, an SPSS file, are included as supplementary material.111Yscopu

    RNA-Guided Genome Editing in Drosophila with the Purified Cas9 Protein

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    We report a method for generating Drosophila germline mutants effectively via injection of the complex of the purified Cas9 protein, tracrRNA, and gene-specific crRNAs, which may reduce delayed mutations because of the transient activity of the Cas9 protein, combined with the simple mutation detection in GO founders by the T7E1 assay.
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