• Title/Summary/Keyword: global $\gamma$-density

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Frontal Gamma-band Hypersynchronization in Response to Negative Emotion Elicited by Films (영상에 의해 유발된 부정적 감정 상태에 따른 전두엽 감마대역 신경동기화)

  • Kim, Hyun;Choi, Jongdoo;Choi, Jeong Woo;Yeo, Donghoon;Seo, Pukyeong;Her, Seongjin;Kim, Kyung Hwan
    • Journal of Biomedical Engineering Research
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    • v.39 no.3
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    • pp.124-133
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    • 2018
  • We tried to investigate the changes in cortical activities according to emotional valence states during watching video clips. We examined the neural basis of two emotional states (positive and negative) using spectral power analysis and brain functional connectivity analysis of cortical current density time-series reconstructed from high-density electroencephalograms (EEGs). Fifteen healthy participants viewed a series of thirty-two 2 min emotional video clips. Sixty-four channel EEGs were recorded. Distributed cortical sources were reconstructed using weighted minimum norm estimation. The temporal and spatial characteristics of spectral source powers showing significant differences between positive and negative emotion were examined. Also, correlations between gamma-band activities and affective valence ratings were determined. We observed the changes of cortical current density time-series according to emotional states modulated by video clip. Gamma-band activities showed significant difference between emotional states for thirty seconds at the middle and the latter half of the video clip, mainly in prefrontal area. It was also significantly anti-correlated with the self-ratings of emotional valence. In addition, the gamma-band activities in frontal and temporal areas were strongly phase-synchronized, more strongly for negative emotional states. Cortical activities in frontal and temporal areas showed high spectral power and inter-regional phase synchronization in gamma-band during negative emotional states. It is inferred that the higher amygdala activation induced by negative stimuli resulted in strong emotional effects and caused strong local and global synchronization of neural activities in gamma-band in frontal and temporal areas.

[ $L^p$ ] NORM INEQUALITIES FOR AREA FUNCTIONS WITH APPROACH REGIONS

  • Suh, Choon-Serk
    • East Asian mathematical journal
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    • v.21 no.1
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    • pp.41-48
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    • 2005
  • In this paper we first introduce a space of homogeneous type X, and then consider a kind of generalized upper half-space $X{\times}(0,\;\infty)$. We are mainly considered with inequalities for the $L^p$ norms of area functions associated with approach regions in $X{\times}(0,\;\infty)$.

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A DECOMPOSITION INTO ATOMS OF TENT SPACES ASSOCIATED WITH GENERAL APPROACH REGIONS

  • Suh, Choon-Serk
    • Journal of the Chungcheong Mathematical Society
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    • v.23 no.3
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    • pp.453-461
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    • 2010
  • We first introduce a space of homogeneous type X, and develop the theory of the tent spaces on the generalized upper half-space $X{\times}(0,{\infty})$. The goal of this paper is to study that every element of the tent spaces $T_{\Omega}^{p}$($X{\times}(0,{\infty})$, $0, can be decomposed into elementary particles which are called "atoms."

Calculation of Proton-Induced Reactions on Tellurium Isotopes Below 60 MeV for Medical Radioisotope Production

  • Kim, Doohwan;Jonghwa Chang;Yinlu Han
    • Nuclear Engineering and Technology
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    • v.32 no.4
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    • pp.361-371
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    • 2000
  • The 123Te(p,n)123I, 124Te(p,n)124I and 124Te(p,2n)123I reactions, among the many reaction channels opened, are the major reactions under consideration from a diagnostic purpose because reaction residuals as the gamma emitters are used for most radiophamaceutical applications involving radioiodine. Based on the available experimental data, the absorption cross sections and elastic scattering angular distributions of the proton-induced nuclear reaction on Te isotopes below 60 MeV are calculated using the optical model code APMNK. The transmission coefficients of neutron, proton, deuteron, trition and alpha particles are calculated by CUNF code and are fed into the GNASH code. By adjusting level density parameters and the pair correction values of some reaction channels, as well as the composite nucleus state density constants of the pre-equilibrium model, the production cross sections and energy-angle correlated spectra of the secondary light particles, as well as production cross sections and energy distributions of heavy recoils and gamma rays are calculated by the statistical plus pre-equilibrium model code GNASH. The calculated results are analysed and compared with the experimental data taken from the EXFOR. The optimized global optical model parameters give overall agreement with the experimental data over both the entire energy range and all tellurium isotopes.

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Evaluation of γ-Aminobutyric Acid (GABA) Production by Lactic Acid Bacteria Using 5-L Fermentor (Lactic Acid Bacteria (LAB)와 5-L 발효기를 이용한 γ-Aminobutyric Acid 생산기술 개발)

  • Kim, Na Yeon;Kim, Ji Min;Ra, Chae Hun
    • Microbiology and Biotechnology Letters
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    • v.49 no.4
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    • pp.559-565
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    • 2021
  • This study aimed to optimize gamma-aminobutyric acid (GABA) production by employing five strains of lactic acid bacteria (LAB) that were capable of high cell growth and GABA production using a modified synthetic medium. GABA production in the strains was qualitatively confirmed via detection of colored spots using thin layer chromatography. Lactobacillus plantarum SGL058 and Lactococcus lactis SGL027 were selected as the suitable strains for GABA production. The conditions of the carbon and nitrogen sources were determined as 5 g/l glucose (L. plantarum SGL058), 5 g/l lactose (L. lactis SGL027), 10 g/l yeast extract (L. plantarum SGL058), and 20 g/l yeast extract (L. lactis SGL027) for GABA production. The cell growth, monitored by optical density at 600 nm, was 5.93 for L. plantarum SGL058. This value was higher than the 3.04 produced by L. lactis SGL027 at 36 h using a 5-L fermenter. The highest concentration of GABA produced was 546.7 ㎍/ml by L. plantarum SGL058 and 404.6 ㎍/ml by L. lactis SGL027, representing a GABA conversion efficiency of (%, w/w) of 4.0% and 3.4%, respectively. The fermentation profiles of L. plantarum SGL058 and L. lactis SGL027 provide a basis for the utilization of LAB in GABA production using a basal synthetic medium.

Comparison of Gut Microbiota between Lean and Obese Adult Thai Individuals

  • Jinatham, Vasana;Kullawong, Niwed;Kespechara, Kongkiat;Gentekaki, Eleni;Popluechai, Siam
    • Microbiology and Biotechnology Letters
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    • v.46 no.3
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    • pp.277-287
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    • 2018
  • Current reports suggest that obesity is a serious global health issue. Emerging evidence has predicted strong links between obesity and the human gut microbiota. However, only a few such studies have been conducted in Asia, and the gut microbiota of lean and obese adult Asians remains largely unexplored. Here, we investigated the potential relationship between gut microbiota, body massindex (BMI), and metabolic parameters in adults from Thailand, where obesity is increasing rapidly. Fecal and blood samples were collected from 42 volunteers who were allocated into lean, overweight, and obese groups. The fecal microbiota was examined by quantitative PCR analysis. Bacteroidetes, Firmicutes, and Staphylococcus spp. and methanogens were most abundant in lean volunteers. Overweight volunteers majorly harbored Christensenella minuta and Akkermansia muciniphila, ${\gamma}-Proteobacteria$, and bacteria belonging to the genus Ruminococcus. Methanogens and bacteria belonging to the phylum Bacteroidetes were negatively correlated with adiposity markers (BMI and waist circumference), but positive correlated with high-density lipoprotein, suggesting that they can be used as leanness markers. While some of our results agree with those of previous reports, results regarding the contributions of specific taxa to obesity were inconsistent. This is the first study to report the adult gut microbiota in Southeast Asian populations using molecular techniques and biochemical markers and provides a foundation for future studies in this field.