Use of Entomophthorales to Control Arthropods

Seon Wu Choi,Ju Rak Lim,Hyung Cheol Moon,Seong Soo Cheong,Yu Shin Nai,Jae Su Kim 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.10

Entomopathogenic fungi infect some arthropod pest and have been used for biological control. Some entomopathogenic fungi have high potential in insect pest management worldwide, and most of researches were given to Hypocreales order of Ascomycota, but little in Zygomycota, such as Entomophthorales in our country. We have identified some species belonging to Entomophthorales and investigated cultural features and ecology of Entomophaga aulicae. E. aulicae in sweet potato fields, where Aedia leucomelas was a dominant pest, had caused epizootics from 2002–2005. E. aulicae-infected A. leucomelas larva were mostly found from August to October and its occurrence was significantly related to the precipitation. E. aulicae were mainly observed in dead A. leucomelas larval populations (infection rate = 41.3% in 2002), rather than other lepidopteran pests. E. aulicae was morphologically and genetically identified and its virulence was characterized in laboratory conditions. Additionally, pest infection by Zoophthora radicans, Neozygites floridana and some Entomophthorales have been identified. On the basis with this information, we need research to predict the prevalence and to develop biological control agent using Entomophthorales including E. aulicae that contribute to regulation of host populations.

The use of RKPM meshfree methods to compute responses to projectile impacts and blasts nearby charges

Hyung-Jin Choi,John Crawford,Youcai Wu 사단법인 한국계산역학회 2010 Computers and Concrete, An International Journal Vol.7 No.2

This paper presents results from a study concerning the capability afforded by the RKPM (reproducing kernel particle method) meshfree analysis formulation to predict responses of concrete and UHPC components resulting from projectile impacts and blasts from nearby charges. In this paper, the basic features offered by the RKPM method are described, especially as they are implemented in the analysis code KC-FEMFRE, which was developed by Karagozian & Case (K&C).

Concrete fragmentation modeling using coupled finite element - meshfree formulations

Wu, Youcai,Choi, Hyung-Jin,Crawford, John E. Techno-Press 2013 Interaction and multiscale mechanics Vol.6 No.2

Meshfree methods are known to have the capability to overcome the strict regularization requirements and numerical instabilities that encumber the finite element method (FEM) in large deformation problems. They are also more naturally suited for problems involving material perforation and fragmentation. To take advantage of the high efficiency of FEM and high accuracy of meshfree methods, a coupled finite element (FE) and reproducing kernel (RK, one of the meshfree approximations) formulation is described in this paper. The coupling of FE and RK approximation is implemented in an evolutionary fashion, where the extent and location of the evolution is dependent on a triggering criteria provided by the material constitutive laws. To enhance computational efficiency, Gauss quadrature is applied to integrate both FE and RK domains so that no state variable transfer is required when mesh conversion is performed. To control the hourglassing that might occur with 1-point integrated hexahedral grids, viscous type hourglass control is implemented. Meanwhile, the FEM version of the K&C concrete (KCC) model was modified to make it applicable in both FE and RK formulations. Results using this code and the KCC model are shown for the modeling of concrete responses under quasi-static, blast and impact loadings. These analyses demonstrate that fragmentation phenomena of the sort commonly observed under blast and impact loadings of concrete structures was able to be realistically captured by the coupled formulation.

Stimulative and Inhibitory Effects of Bacteria on Microalgal Biomass Production

Wu-Young JEONG,Hyung Joo KIM,Hak Jin SONG,Tae Hang YOON,Ji Eun KIM,Yunjeong YANG,Eun Bin LEE,Yong-Keun CHOI 한국생물공학회 2018 한국생물공학회 학술대회 Vol.2018 No.10

물 분해 과정에서 효율적인 촉매 특성을 보이는 Co₃O₄ nanocubes 합성

최형욱 ( Hyung Wook Choi ),정동인 ( Dong In Jeong ),( Shengyuan Wu ),( Mohit Kumar ),강봉균 ( Bong Kyun Kang ),양우석 ( Woo Seok Yang ),윤대호 ( Dae Ho Yoon ) 한국복합재료학회 2019 Composites research Vol.32 No.6

고효율의 물 분해 시스템은 수소 발생 반응(HER)과 산소 발생 반응(OER) 각각에서의 촉매로 인한 전기화학적 반응에서의 효율로 인해 향상되는 높은 과전압의 감소가 수반되어야 한다. 그 중에서도 전이 금속 기반의 화합물(산화물, 황화물, 인화물, 그리고 질화물)은 현재 상용되고 있는 귀금속을 대체할 촉매 재료로써 주목받고 있다. 본 연구에서, 우리는 FESEM 분석을 통해 최적의 단분산된 Co₃[Co(CN)₆]₂ PBAs를 합성하고 XRD, FT-IR 분석을 통하여 결정성을 확인하고 TG-DTA를 통해 PBAs의 열적 거동을 확인하였다. 그리고 합성된 최적의 Co₃[Co(CN)₆]₂ PBAs를 열처리해서 단분산된 Co₃O₄ 나노 큐브를 합성하였고 XRD를 통해 이의 결정성을 확인하고 OER 측정을 진행하였다. 최종적으로 합성된 Co₃O₄ 나노 큐브는 10 mA·cm^-2의 전류 밀도에서 312 mV의 낮은 과전압과 96.6 mV·dec^-1의 낮은 Tafel slope을 보인다. The high efficient water splitting system should involve the reduction of high overpotential value, which was enhanced by the electrocatalytic reaction efficiency of catalysts, during the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) reaction, respectively. Among them, transition metal-based compounds (oxides, sulfides, phosphides, and nitrides) are attracting attention as catalyst materials to replace noble metals that are currently commercially available. Herein, we synthesized optimal monodisperse Co₃[Co(CN)₆]₂ PBAs by FESEM, and confirmed crystallinity by XRD and FT-IR, and thermal behavior of PBAs via TG-DTA. Also, we synthesized monodispersed Co₃O₄ nanocubes by calcination of Co₃[Co(CN)₆]₂ PBAs, confirmed the crystallinity by XRD, and proceeded OER measurement. Finally, the synthesized Co₃O₄ nanocubes showed a low overpotential of 312 mV at a current density of 10 mAㆍcm^-2 with a low Tafel plot (96.6 mVㆍdec^-1).

Transient Receptor Potential Canonical 4 and 5 Channel Antagonist ML204 Depolarized Pacemaker Potentials of Interstitial Cells of Cajal

( Jun Hyung Lee ),( Wen-hao Wu ),( Xing-you Huang ),( Jae Yeoul Jun ),( Seok Choi ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2020 Journal of Neurogastroenterology and Motility (JNM Vol.26 No.4

Background/Aims To investigate an effect of ML204 (an inhibitor of transient receptor potential canonical 4 and 5 [TRPC4/5] channels) on interstitial cells of Cajal (ICCs) and therefore determine whether TRPC4/5 channels act on ICC-generated pacemaker activity. Methods We enforced whole cell patch clamp analysis, measurements of the intracellular Ca2+ concentration, and reverse transcription polymerase chain reaction to determine the effect of ML204 (10 μM) or englerin A (a selective activator of TRPC4/5 channeles, 10 μM) and the existence of TRPC4/5 in mouse small intestinal ICC. Results Treatment of ICCs with ML204 or englerin A caused the membrane potentials to depolarize. This depolarization effect of membrane potentials by ML204 in ICCs was observed to be concentration-dependent. After treating Ca²⁺- and Na⁺-free solutions or flufenamic acid (a non-selective cation channel blocker), the pacemaker potentials in the ICCs were abolished. A specific anoctamin 1 channel blocker did not have any effect on the pacemaker activity in ML204-untreated control cells; however, they blocked ML204-induced pacemaker activity in ICCs. Specific primers designed against TRPC4 and TRPC5 detected the presence of TRPC4/5 in small intestinal ICCs, and the application of ML204 increased raise the frequency of Ca²⁺ oscillations in ICCs, as assessed using Fluo-4 AM. Conclusion The results implied that ML204 could not inhibit the pacemaker activity but depolarized the membrane potential of ICCs by regulating intracellular Ca²⁺ oscillations and anoctamin 1 channels. (J Neurogastroenterol Motil 2020;26:521-528)

Effect of Phytohormones and Chemical Inhibitors on Pathogenesis-related Genes Identified by Differential Hybridization in Rice Suspension Culture Cells

김상곤,Jingni Wu,Ethan E White,Young Whan Choi,Keun-Ki Kim,In Soo Choi,Sun-Hyung Kim,강규영,김선태,Yiming Wang,김용철 한국식물병리학회 2010 Plant Pathology Journal Vol.26 No.4

In order to study disease resistance mechanisms in rice against the rice blast fungus Magnaporthe grisea, we screened fungal elicitor-responsive genes from rice suspension-cultured cells treated with fungal elicitors employing differential hybridization (DH). By DH screening,31 distinct rice clones were isolated and a majority of them were full-length cDNAs encoding pathogenesisrelated (PR) genes. Sixteen of the 31 genes were upregulated at 4, 8, and 12 h following fungal elicitor treatment. To elucidate the effect of signal molecules and biotic elicitors on the regulation of rice defense genes, we further characterized the transcriptional expression patterns of representative isolated PR genes;OsGlu1, OsGlu2, OsTLP, OsRLK, and OsPR-10, following treatment with fungal elicitor, phytohormones, cycloheximide,and inhibitors of protein phosphorylation. Jasmonic acid (JA) induced transcriptional expression of OsGlu1, OsTLP, and OsRLK, but not of OsGlu2 and OsPR-10 at any of the tested time points. Salicylic acid (SA) and abscisic acid weakly induced the expression of OsTLP and OsRLK. SA showed an antagonistic effect with fungal elicitor and JA. Cycloheximide suppressed all these genes upon elicitor treatment, except for OsGlu2. Staurosporine only induced the expression of OsRLK. Application of calyculin A strongly induced OsRLK expression, but suppressed the expression of OsGlu2. Our study yielded a number of PR genes that play a role in defense mechanisms against the rice blast fungus, as well as contribute towards the elucidation of crosstalk between phytohormones and other modifications during defense signaling

Altered Eye-Movement Patterns During Text Reading in Obsessive–Compulsive Disorder and Internet Gaming Disorder

Lee, Tak Hyung,Kim, Minah,Kwak, Yoo Bin,Hwang, Wu Jeong,Kim, Taekwan,Choi, Jung-Seok,Kwon, Jun Soo Frontiers Media S.A. 2018 Frontiers in Behavioral Neuroscience Vol.12 No.-

<P>Obsessive-compulsive disorder (OCD) and internet gaming disorder (IGD), which are similar in that both involve repetitive behaviors and related with cognitive dysfunctions, frequently begin in early adolescence, which is a critical period for learning. Although the deterioration in cognitive functioning caused by these conditions may have adverse effects on information processing, such as text reading, there has been no comprehensive research on the objective indicators of altered reading patterns in these patients. Therefore, we evaluated eye-movement patterns during text reading in patients with OCD or IGD. In total, 20 patients with OCD, 28 patients with IGD and 24 healthy controls (HCs) participated in the reading task using an eye tracker. We compared the fixation durations (FDs), saccade amplitudes and eye-movement regressions of the three groups during reading. We explored relationships between the parameters reflecting altered reading patterns and those reflecting the severity of clinical symptoms. The average FDs and forward saccade amplitudes did not differ significantly among the groups. There were more eye-movement regressions in patients with OCD than in patients with IGD and HCs. No correlation was found between altered eye-movement patterns during reading and the severity of clinical symptoms in any of the patient groups. The significantly increased number of regressions (NRs) in the OCD group during reading may reflect these patients’ difficulties with inferential information processing, whereas the reading pattern in the IGD group is relatively intact. These findings suggest that patients with OCD and patients with IGD have different eye-movement patterns during reading reflecting distinct cognitive impairments in the two patient groups.</P>

폴리페놀, 안토시아닌과 비타민 C 함량이 우수한 감자 계통 선발

김성무(Cheng Wu Jin),최형식(Hyung Sic Choi),이우종(Woo Jong Lee),강위수(Wi Soo Kang),임학태(Hak Tae Lim) 한국원예학회 2016 원예과학기술지 Vol.34 No.4

폴리페놀, 안토시아닌과 비타민 C 함량이 우수한 감자 계통 선발

김성무(Cheng Wu Jin),최형식(Hyung Sic Choi),이우종(Woo Jong Lee),강위수(Wi Soo Kang),임학태(Hak Tae Lim) 한국원예학회 2016 원예과학기술지 Vol.34 No.3

To develop appropriate potato clones as functional food materials, we collected 35 potato breeding clones to analyze the contents of the total polyphenol, anthocyanin, and vitamin C with the ‘Superior’, ‘Dasom valley’, and ‘Gogu valley’ cultivars as controls. Based on our analysis great differences were observed in different potato clones. KPG16 had the highest content of total polyphenol at 105.08 ㎎·100g<SUP>-1</SUP> FW; KPG13 had the highest content of anthocyanin at ·4.78 ㎎100g<SUP>-1</SUP> FW; KPG20 had the highest content of vitamin C at 22.16 ㎎·100g<SUP>-1</SUP> FW. Some clones had higher contents of the total polyphenol but lower levels of anthocyanin. Ultimately, potato clones showing relatively high indexes for all three compounds, could be considered as good functional food material. By equilibrium analysis of the contents of total polyphenol, anthocyanin, and vitamin C, KPG5 showed relatively higher contents, with values of 103.95, 3.15, 12.12 ㎎·100g<SUP>-1</SUP> FW, respectively. Therefore, KPG5 was considered to be the best potato breeding clone in view of a functional potato breeding system.