• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.185-191
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• 2001

To obtain the basic information for degradation of remaining pesticide accumulated in cultivated soil of Honam area, the resistant bacterial strains were investigated in Chlorothalonil(TPN). Mancozeb, Bentazone, and Butachlor levels of 100, $500{\mu}g\;ml^{-1}$, and degradation of TPN by TPN-resistant bacteria in sterilized soil was studied under TPN levels 0, 10, 50 and $100{\mu}g\;g^{-1}$. A number of resistance strains were decreased with higher at concentration level of pesticide, and were higher in greenhouse than upland or paddy soil. The resistance of bacteria was strong in other of Bentazone> Butachlor> TPN> Mancozeb. The percentage of bacterial strains of resistance for pesticides isolated from the cultivated soil were the highest in Acinetobacter spp. and Corynebacterium spp., and the lowest in Moraxella spp. A number of TPN-resistant strains were the highest at the TPN level of $10{\mu}g\;g^{-1}$, and 5 days after strains inoculation, and were higher in Pseudomonas spp. TD-25 than TC-23 or strains in non-sterilized soil. The degradation of TPN was fast in order of strain TD-25>strain in non-sterilized soil >TC-23.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.629-634
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• 2017

In the case of the UHP (Ultra high performance) tire that the demand has increased rapidly, compared with the commonly used tire, severe deformation has been observed because of the low aspect ratio. When repeated deformations are applied to the sidewall rubber, accumulated fatigue damage may cause fatigue failure. Thus, the evaluation of the durability of the tire sidewall rubber has become a very important issue to prevent accidents that occur while the vehicle is running. However, the research and design criteria for the durability performance of the tire sidewall rubber hardly exist. In this study, we suggest a lifetime prediction formula using strain energy density obtained by performing tensile tests and fatigue tests on two different kinds of the tire sidewall compounds. Additionally, the applicability of our findings for low fuel consumption tires was reviewed by converting the fatigue life of the sidewall rubber into the expected mileage of the tire.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.402-409
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• 2006

Although microorganisms are, in fact, the most diverse and abundant type of organism on Earth, the ecological functions of microbial populations remains poorly understood. A variety of bacteria including marine Vibrios encounter numerous ecological challenges, such as UV light, predation, competition, and seasonal variations in seawater including pH, salinity, nutrient levels, temperature and so forth. In order to survive and proliferate under variable conditions, they have to develop elaborate means of communication to meet the challenges to which they are exposed. In bacteria, a range of biological functions have recently been found to be regulated by a population density-dependent cell-cell signaling mechanism known as quorum-sensing (QS). In other words, bacterial cells sense population density by monitoring the presence of self-produced extracellular autoinducers (AI). N-acylhomoserine lactone (AHL)-dependent quorum-sensing was first discovered in two luminescent marine bacteria, Vibrio fischeri and Vibrio harveyi. The LuxI/R system of V. fischeriis the paradigm of Gram-negative quorum-sensing systems. At high population density, the accumulated signalstrigger the expression of target genes and thereby initiate a new set of biological activities. Several QS systems have been identified so far. Among them, an AHL-dependent QS system has been found to control biofilm formation in several bacterial species, including Pseudomonas aeruginosa, Aeromonas hydrophila, Burkholderia cepacia, and Serratia liquefaciens. Bacterial biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix that adheres to an inert or living surface. Extracellular signal molecules have been implicated in biofilm formation. Agrobacterium tumefaciens strain NT1(traR, tra::lacZ749) and Chromobacterium violaceum strain CV026 are used as biosensors to detect AHL signals. Quorum sensing in lactic acid bacteria involves peptides that are directly sensed by membrane-located histidine kinases, after which the signal is transmitted to an intracellular regulator. In the nisin autoregulation process in Lactococcus lactis, the NisK protein acts as the sensor for nisin, and NisR protein as the response regulator activatingthe transcription of target genes. For control over growth and survival in bacterial communities, various strategies need to be developed by which receptors of the signal molecules are interfered with or the synthesis and release of the molecules is controlled. However, much is still unknown about the metabolic processes involved in such signal transduction and whether or not various foods and food ingredients may affect communication between spoilage or pathogenic bacteria. In five to ten years, we will be able to discover new signal molecules, some of which may have applications in food preservation to inhibit the growth of pathogens on foods.

• Journal of the Korean Geosynthetics Society
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• v.20 no.1
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• pp.45-55
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• 2021

In this study, the behavioral characteristics of the fill dam were analyzed during water level fluctuations through a numerical analysis model, and the reservoir safety management plan was prepared. The variation in plastic deviatoric strain, horizontal displacement, stress path, pore water pressure, etc., due to elevation of water level in the upper and lower sides of shell and core were analyzed using numerical analysis software, viz. GTS NX and LIQCA. The analysis results manifest that as the water level in the dam body increases rapidly, the pore water pressure and displacement also increase quickly. It was found that the elevation of the water level causes an increase in pore water pressure in the dam body as well as an increase in the saturation of the dam body and decreased effective stress. It is considered that this type of dam behavior can be the cause of the reduction of strength and stiffness of the dam. Also, it is assumed that the accumulated plastic deviatoric strain due to the deformation of the dam body caused by water infiltration causes an increase in displacement. Based on these experimental results and the results of analyses of the existing reservoir safety diagnosis techniques, an improvement plan for dam safety diagnosis and evaluation criteria was proposed, and these results can be used as primary data while revising dam safety diagnosis guidelines.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.78.2-79
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• 2003

Pepper defensin ( CADEFl) clone was isolated from cDNA library constructed from pepper leaves infected with avirulent strain Bv5-4a of Xanthomonu campestris pv. vesicatoria. The deduced amino acid sequence of CADEFl is 82-64％ identical to that of other plant defensins. Putative protein encoded by CADEFl gene consists of 78 amino acids and 8 conserved cysteine residues to form four structure-stabilizing disulfide bridges. Transcription of the CADEF1 gene was earlier and stronger induced by X campestris pv. vesicatoria infection in the incompatible than in the compatible interaction. CADEF1 mRNA was constitutively expressed in stem, root and green fruit of pepper. Transcripts of CADEFl gene drastically accumulated in pepper leaf tissues treated With Salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), hydrogen Peroxide (H$_2$O$_2$), benzothiadiazole (BTH) and DL-${\beta}$-amino-n-butyric acid (BABA). In situ hybridization results revealed that CADEF1 mRNA was localized in the phloem areas of vascular bundles in leaf tissues treated with exogenous SA, MeJA and ABA. Strong accumulation of CADEF1 mRNA occurred in pepper leaves in response to wounding, high salinity and drought stress. These results suggest that bacterial pathogen infection, abiotic elicitors and some environmental stresses may play a significant role in signal transduction pathway for CADEF1 gene expression.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.568-570
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• 2003

The Hyoscyamus niger hyoscyamine $6{\beta}-hydroxylase$ (H6H, EC 1.14.11.11) gene was introduced into the genome of a Scopolia parviflora by the binary vector system using the disarmed Agrobacterium rhizogenes strain KCTC 2703. Expression of H6H enzyme which are involved in alkaloids pathway by western blot analysis using proteins extracted from leaf, stem flower, branch root and main root were examined The enzyme expression was found only in the roots, with no expression in leaf, stem and flower. The alkaloids contents were the most higher in root and then leaf and stem has very small amount of alkaloid contents were analyzed by HPLC. The expression level of H6H in transgenic plants were two or more times than wild type plants. In transgenic plant which constitutively expresses H6H enzyme, high concentration of scopolamine was accumulated.

• Journal of Environmental Impact Assessment
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• v.15 no.4
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• pp.279-288
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• 2006

Saemangeum reclamation project was started in 1991 with the purpose of eco-friendly reclamation, but without clear definition of eco-friendliness. This study was carried out to find out the environmental indicators to define and evaluate the eco-friendliness of Saemangeum project. The methodology to identify the indicators included the analysis of similar reclamation projects, professional discussions, and Delphi survey. The eco-friendly indicators are theoretically based on the five elements of eco-friendliness; 1) resource consumption, 2) energy consumption, 3) pollution emission, 4) bio-diversity, 5) social amenity. The 69 indicators were explained in detail for the convenient use of the indicators by the potential users. The 69 indicators were classified into three categories such as pre-evaluation, process evaluation, and post-evaluation. In terms of spatial consideration, the 69 indicators were classified into two categories such as direct influence area and indirect influence area. Also the 69 indicators were classified into 7 categories: 1) sea, 2) lake, 3) agricultural land use, 4) industrial land use, 5) residential land use, 6) tourism land use, and 7) environmental land use. Twenty core indicators were selected from the 69 indicators by surveying the importance of each indicator. The core indicators are recommended in case of time and budget strain. When there are few quantitative data accumulated for the reclamation project, 5 macro indicators are recommended to be used. Macro indicators are qualitative in nature, and may be used in order to evaluate the overall eco-friendliness of a reclamation project.

• Earthquakes and Structures
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• v.14 no.4
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• pp.337-347
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• 2018

This paper presents some shaking table tests conducted on a 1/4-scaled model with 5-story steel reinforced concrete (SRC) spatial frame with irregular section columns under a series of base excitations with gradually increasing acceleration peaks. The test frame was subjected to a sequence of seismic simulation tests including 10 white noise vibrations and 51 seismic simulations. Each seismic simulation was associated with a different level of seismic disaster. Dynamic characteristic, strain response, acceleration response, displacement response, base shear and hysteretic behavior were analyzed. The test results demonstrate that at the end of the loading process, the failure mechanism of SRC frame with irregular section columns is the beam-hinged failure mechanism, which satisfies the seismic code of "strong column-weak beam". With the increase of acceleration peaks, accumulated damage of the frame increases gradually, which induces that the intrinsic frequency decreases whereas the damping ratio increases, and the peaks of acceleration and displacement occur later. During the loading process, torsion deformation appears and the base shear grows fast firstly and then slowly. The hysteretic curves are symmetric and plump, which shows a good capacity of energy dissipation. In summary, SRC frame with irregular section columns can satisfy the seismic requirements of "no collapse under seldom earthquake", which indicates that this structural system is suitable for the construction in the high seismic intensity zone.

• Microbiology and Biotechnology Letters
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• v.15 no.5
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• pp.361-367
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• 1987

A DL-seleno-methionine resistant mutant, Cephalosporium acremonium MS-92 showed increased activities of sulfate and L-methionine uptake than the parent strain, and accumulated excess methionine and S-adenosylmethionine (SAM) intracellularly. And the sulfate uptake system was severely inhibited by L-cysteine. In crude enzyme extracts, the mutant MS-92 showed lower L-serine sulfhydrylase (identical with cystathionine $\beta$-synthase) activity than the parent. Also, cysteine desulfhydrylase activity, an index of intracellular L-cysteine concentration, of the mutant MS-92 was decreased by about 50% as com-pared with that of the parent. Thus, it was supposed that the mutant MS-92 should have n lower level of L-cysteine than the parent. In C. acremonium like A. nidulans, the enzymes related to the biosynthesis of methionine might be regulated by L-cysteine, but not by methionine or SAM.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1833-1840
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• 2007

Viruses in garlic plants (Allium sativum L.) have accumulated and evolved over generations, resulting in serious consequences for the garlic trade around the world. These viral epidemics are also known to be caused by aphids and eriophyid mites (Aceria tulipae) carrying Potyviruses, Carlaviruses, and Allexiviruses. However, little is known about viral epidemics in garlic plants caused by eriophyid mites. Therefore, this study investigated the infection of garlic plants with Allexiviruses by eriophyid mites. When healthy garlic plants were cocultured with eriophyid mites, the leaves of the garlic plants developed yellow mosaic strips and became distorted. In extracts from the eriophyid mites, Allexiviruses were observed using immunosorbent electron microscopy (ISEM). From an immunoblot analysis, coat proteins against an Allexivirus garlic-virus antiserum were clearly identified in purified extracts from collected viral-infected garlic plants, eriophyid mites, and garlic plants infected by eriophyid mites. A new strain of GarV-B was isolated and named GarV-B Korea isolate 1 (GarV-B1). The ORF1 and ORF2 in GarV-B1 contained a typical viral helicase, RNA-directed RNA polymerase (RdRp), and triple gene block protein (TGBp) for viral movement between cells. The newly identified GarV-B1 was phylogenetically grouped with GarV-C and GarV-X in the Allexivirus genus. All the results in this study demonstrated that eriophyid mites are a transmitter insect species for Allexiviruses.