• Title/Summary/Keyword: Strain Control

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Studies on the Cellulase of Penicillium sp. Isolated from Soils - (II) Culture Conditions of Penicillium sp. C13-13 Strain - (토양에서 분리한 Penicillium sp.가 생산하는 Cellulase에 관한 연구 - (II) Penicillium sp. C13-13 주(株)의 배양조건 검토 -)

  • Kim, Yong-Bae;Yi, Pyung-Kuk;Choi, Seung-Ho
    • The Korean Journal of Mycology
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    • v.2 no.1
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    • pp.25-29
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    • 1974
  • 1. Penicillium sp. C 13-13 strain was obtained with the treatment of mutagenic agents(N.T.G.) and by single spore isolation method from the Penicillium sp. C8-14 strain, which was reported in the previous paper. 2. The above strain had a few spores and to obtain seed culture, it was cultured at $30^{\circ}C$ and initial pH $4.5{\sim}5.0$, with air rate 6l/min., and agitation 600 rpm for 48 hours in 10% wheat bran medium in 20l- Jar fermenter. When the broth that had above 70ml of mycelium was inoculated into wheat bran medium and incubated at $29{\sim}33^{\circ}C$ for 72 hrs, the cellulase activity of the koji was higher. 3. Adding calcium chloride and magnecium sulfate to the wheat bran medium to 1.5% and 0.015% respectively, the cellulase activity of the koji was higher than that of the control.

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Kinematics of filament stretching in dilute and concentrated polymer solutions

  • McKinley, Gareth H.;Brauner, Octavia;Yao, Minwu
    • Korea-Australia Rheology Journal
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    • v.13 no.1
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    • pp.29-35
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    • 2001
  • The development of filament stretching extensional rheometers over the past decade has enabled the systematic measurement of the transient extensional stress growth in dilute and semi-dilute polymer solutions. The strain-hardening in the extensional viscosity of dilute solutions overwhelms the perturbative effects of capillarity, inertia & gravity and the kinematics of the extensional deformation become increasingly homogeneous at large strains. This permits the development of a robust open-loop control algorithm for rapidly realizing a deformation with constant stretch history that is desired for extensional rheometry. For entangled fluids such as concentrated solutions and melts the situation is less well defined since the material functions are governed by the molecular weight between entanglements, and the fluids therefore show much less pronounced strain-hardening in transient elongation. We use experiments with semi-dilute/entangled and concentrated/entangled monodisperse polystyrene solutions coupled with time-dependent numerical computations using nonlinear viscoelastic constitutive equations such as the Giesekus model in order to show that an open-loop control strategy is still viable for such fluids. Multiple iterations using a successive substitution may be necessary, however, in order to obtain the true transient extensional viscosity material function. At large strains and high extension rates the extension of fluid filaments in both dilute and concentrated polymer solutions is limited by the onset of purely elastic instabilities which result in necking or peeling of the elongating column. The mode of instability is demonstrated to be a sensitive function of the magnitude of the strain-hardening in the fluid sample. In entangled solutions of linear polymers the observed transition from necking instability to peeling instability observed at high strain rates (of order of the reciprocal of the Rouse time for the fluid) is directly connected to the cross-over from a reptative mechanism of tube orientation to one of chain extension.

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Phylogenetic analysis of marine birnavirus (MABV) isolated from cultured starry flounder Platichthys stellatus and olive flounder Paralichthys olivaceus in Korea (양식 강도다리, Platichthys stellatus 및 넙치, Paralichthys olivaceus에서 분리한 marine birnavirus (MABV)의 phylogenetic 분석)

  • Park, Shin-Hoo;Park, Myoung-Ae;Cho, Mi-Young
    • Journal of fish pathology
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    • v.22 no.3
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    • pp.211-218
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    • 2009
  • In this study, we have compared the genome of marine birnavirus (MABV) detected from starry flounder Platichthys stellatus and olive flounder Paralichthys olivaceus. A molecular analysis based on the nucleotide sequence (433 bases) of VP2-NS-VP3 region revealed that MABV (08-KU) from starry flounder showed 98% similarity with MABV Y6 isolated from Yellowtail Seriola quinqueradita in Japan (Accession no: AY283781) and with other aquabirnaviruses identify more than 76%. Comparison with MABV strains (06-KP, 08-KC) from olive flounder and MABV Y6 strain showed 97-98% sequence identities. Phylogenetic analysis was performed in order to examine the relationship among previously determined aquatic birnaviruses isolates showed that MABV and IPNV strains were classified into seven clusters. Three isolates from starry flounder and olive flounder in this study, belong to the genogroup VII including MABV Y6 strain and other aquabirnaviruses isolated from marine fish and molluscan shellfish in Japan. This report is the first description of a MABV from starry flounder in Korea.

Pathogenicity of Entomopathogenic Nematode, Steinernema carpocapsae against Fall Webworm, Hyphanria cunea (Lepidoptera: Arctiidae) (미국흰불나방(Hyphanria cunea)에 대한 곤충병원성선충 Steinernema carpocapsae의 병원성)

  • Park Hyung Soon;Kim Hyeong Hwan;Chung Hun Gwan;Cho Yoon Sin;Jeon Heung Yong;Jang Han Ik;Kim Dong Soo;Choo Ho Yul
    • Asian Journal of Turfgrass Science
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    • v.18 no.4
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    • pp.193-200
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    • 2004
  • Environmentally sound control of fall webworm, Hyphanria cunea (Drury) with entomopathogenic nematode, Sreinernema carpocapsae Pocheon strain was evaluated in the laboratory and pot. Pathogenicity of 5. carpocapsae Pocheon strain was different depending on larval stage, i.e., mortality of the 2nd instar and the $3\~4th$ instar was $100\%$ with >20 infective juveniles (Ijs)/larva in 3 days, but the 5th instar was $34\%$ with (Ijs)/larva in 3 days. Pathogenicity of 5. carpocapsae Pocheon strain was higher with increasing nematode concentration. Mortality of Hyphanria cunea larva by 5. carpocapsae Pocheon strain was not significantly different (more than $70\%$) between nematode concentration on treated trees (Malus alba and Platanus orientalis) and in pot.

A Study of Adolescents' Status Offenses Based on General Strain Theory - Experiencing Child Abuse as a Strain Factor - (일반긴장이론에 근거한 청소년 지위비행에 관한 연구 - 긴장요인으로서의 자녀학대경험을 중심으로 -)

  • Kim, Jea-yob;Song, Ah-young;Park, Kyung-na
    • Korean Journal of Social Welfare Studies
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    • no.37
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    • pp.295-318
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    • 2008
  • The purpose of this study is to examine the validity of adolescent's status offenses model based on general strain theory. To perform this research, a survey was conducted to adolescents of mixed gender from middle and high schools in Seoul and Gyeonggi Province, who were 9th to 11th grade students. A total of 1167 cases were collected, and without 27 inappropriate cases, 1140 cases were used for the analysis. A structural equation model was applied to the child abuse experience with depression mediator and the adolescents status offense, and the calculation of model fit index reached to .986(TLI), .994(CFI), and .032(RMSEA). The result of Aroian test on the effectiveness of depression as a mediator demonstrates that depression has a prominent effect as a mediator to the model. However, the self control of an adolescent, which were presented in this research as a primary moderating variable, did not display any salient effect on the course of a depression developing to the level of status offense.

NaCl Concentration-Dependent Aminoglycoside Resistance of Halomonas socia CKY01 and Identification of Related Genes

  • Park, Ye-Lim;Choi, Tae-Rim;Kim, Hyun Joong;Song, Hun-Suk;Lee, Hye Soo;Park, Sol Lee;Lee, Sun Mi;Kim, Sang Hyun;Park, Serom;Bhatia, Shashi Kant;Gurav, Ranjit;Sung, Changmin;Seo, Seung-Oh;Yang, Yung-Hun
    • Journal of Microbiology and Biotechnology
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    • v.31 no.2
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    • pp.250-258
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    • 2021
  • Among various species of marine bacteria, those belonging to the genus Halomonas have several promising applications and have been studied well. However, not much information has been available on their antibiotic resistance. In our efforts to learn about the antibiotic resistance of strain Halomonas socia CKY01, which showed production of various hydrolases and growth promotion by osmolytes in previous study, we found that it exhibited resistance to multiple antibiotics including kanamycin, ampicillin, oxacillin, carbenicillin, gentamicin, apramycin, tetracycline, and spectinomycin. However, the H. socia CKY01 resistance pattern to kanamycin, gentamicin, apramycin, tetracycline, and spectinomycin differed in the presence of 10% NaCl and 1% NaCl in the culture medium. To determine the mechanism underlying this NaCl concentration-dependent antibiotic resistance, we compared four aminoglycoside resistance genes under different salt conditions while also performing time-dependent reverse transcription PCR. We found that the aph2 gene encoding aminoglycoside phosphotransferase showed increased expression under the 10% rather than 1% NaCl conditions. When these genes were overexpressed in an Escherichia coli strain, pETDuet-1::aph2 showed a smaller inhibition zone in the presence of kanamycin, gentamicin, and apramycin than the respective control, suggesting aph2 was involved in aminoglycoside resistance. Our results demonstrated a more direct link between NaCl and aminoglycoside resistance exhibited by the H. socia CKY01 strain.

Effect of Heavy Metal Resistant and Halotolerant Rhizobacterium Bacillus safensis KJW143 on Soybean under Salinty and Cadmium Exposure

  • Eun-Hae Kwon;Ho-Jun Gam;Yosep Kang;Jin-Ryeol Jeon;Ji-In Woo;Sang-Mo Kang;In-Jung Lee
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2023.04a
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    • pp.32-32
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    • 2023
  • Cadmium and salt exposure to crops is considered vulnerable for production as well as consumption. To address these challenges, the current study aimed to mitigate the toxicity induced by salt and cadmium in soybean plants through the application of bacterial strain Bacillus safensis KJW143 isolated from the rhizosphere of oriental melon..The bioassay analysis revealed that KJW143 is a highly salt-tolerant and cadmium-resistant (Cd) strain with an innate ability to produce melatonin, gibberellin (GA3), Indole-3-Acetic Acid (IAA), and organic acids (i.e., acetic, succinic, lactic, and propionic acids). Soybean plants at 20 days old were treated with KJW143 in a different form (pellet, broth, and together) and their effect on plant performance was investigated. Inoculation with KJW143enhanced plant biomass and growth attributes in soybean plants compared to the control (non-treated). In particular, we observed that only pellet-treated showed 65%, 27.5%, and 28.7% increase in growth (shoot fresh weight) compared to broth, broth with pellet, and control. In addition, bacterial strain KJW143 treatment (only pellet) modulated the physiochemical apparatus of soybean plants by increasing glucose (390%), arabinose (166%), citric acid (22.98%) and reducing hydrogen peroxide (29.7%), catalase (32.1%), salicylic acid (25.6%) compared to plants with combined stressed plants (cd and salinity). These findings suggest that bacterial strain KJW143 could be usedas a biofertilizer to minimize the probable risk of heavy metal and salinity stress on crops.

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Cloning of a Hemolytic Mosquitocidal Delta-endotoxin Gene (cyt) of Bacillus thuringiensis 73E10-2 (serotype 10) into Bacillus subtilis and Characterization of the cyt Gene Product

  • Kim, Kwang-Hyeon;Ohba, Michio;Kim, Byung-Woo
    • Journal of Microbiology and Biotechnology
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    • v.6 no.5
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    • pp.326-330
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    • 1996
  • To illustrate whether a hemolysin in $\delta$-endotoxins of Bacillus thuringiensis strain 73E10-2 and subsp. israelensis had immunological identity, a cyt gene of the strain 73E10-2 which encodes a hemolysin was cloned to B. subtilis (transformant 2753). The transformant 2753 containing cyt gene produced the hemolysin which lysed sheep erythrocytes after treatment of proteinase K. The hemolysin was proved also to be toxic against mosquito larvae (Aedes aegypti). The molecular weight of the hemolysin produced from the transformant 2753 was determined to be about 25 kDa by SDS-PAGE and immunoblot. The hemolysin in $\delta$-endotoxin of subsp. israelensis and subsp. kyushensis did not react on immunoblot using polyclonal anti-$\delta$-endotoxin of the strain 73E10-2, but 70-140 kDa mosquitocidal toxins in $\delta$-endotoxin of subsp. kyushuensis reacted.

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Design Optimization of Ball Grid Array Packaging by the Taguchi Method

  • Kim, Yeong-K.;Kim, Jae-chang;Choi, Joo-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.17 no.4
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    • pp.67-72
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    • 2010
  • In this paper, a design optimization of ball grid array packaging geometry is studied based on the Taguchi method, which allowed robust design by considering the variance of the input parameters during the optimization process. Molding compound and substrate were modeled as viscoelastic, and finite element analyses were performed to calculate the strain energy densities of the eutectic solder balls. Six quality factors of the dimensions of the packaging geometry were chosen as control factors. After performing noise experiments to determine the dominant factors, main experiments were conducted to find the optimum packaging geometry. Then the strain energy densities between the original and optimized geometries were compared. It was found that the effects of the packaging geometry on the solder ball reliability were significant, and more than 40% of the strain energy density was reduced by the geometry optimization.

The Effects of Vegetable Extracts on the Growth of Listeria monocytogenes (채소추출물이 Listeria monocytogenes의 생육에 미치는 영향)

  • 정종화;김동술;조태웅;강성조;김성영;정덕화
    • Journal of Food Hygiene and Safety
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    • v.10 no.1
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    • pp.7-12
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    • 1995
  • The inhibitory effects of vegetables, collected from Jinju district, on the growth of Listeria monocytogenes were investigated. Among 12 vegerables, garlic, leek, onion and cabbage were remarkably effective to inhibit the growth of the strain. Especially with the addition of extract equivalent 0.25g of raw garlic per ml broth, the population of the strain was decreased wignificantly, and completely inhibited with the addition of 0.625g or more. During the incubation with the addition of extract equivalent 0.25g of raw garlic per ml broth, the degree of inhibition was gradually increased with the lapse of time, and completely inhibited the growth of the strain after 48 hrs. While the pH value of treated broth remained unchanged almost, those of control were slightly reduced.

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