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        검색결과 116

        62.
        2019.04 구독 인증기관·개인회원 무료
        The global biopesticide market was estimated to become about 4% of the total crop protection market in 2015, mainly due to variability of their efficacy, narrow spectrum or difficulties in long-term storage. Therefore, many people focus on overcoming these issues as a big trend. Suggested solutions include the investigation of synergy between microorganisms, the use of genetic engineering, improving the pesticide life shelf, etc. As a result, biopesticides market has grown by more than 17% over the last decade. In this context and aiming to develop new entomopathogenic fungi–based pest management tools, we constructed a fungal library by isolating insect pathogenic fungi from soil. A total of 581 isolates belonging to 35 species were isolated and characterized. Beauveria bassiana was the most abundant, representing 38.55% of the total strains, followed by Metharizium anisopliae (22.55%) and bubillosa (8.6). …% of the total isolates were highly virulent against Tenebrio molitor killing most of the treated insects in 2 to 3 days.
        63.
        2019.04 구독 인증기관·개인회원 무료
        Developmental characteristics of immature stages of Ostrinia scapulalis (Lepidoptera: Crambidae), which is a main insect pest against legume crops, were investigated at constant temperatures to prepare fundamental data for integrated pest management. Egg, larva and pupa could survive at temperatures from 16oC to 36oC. Developmental periods of those stages became shorter with increasing temperature between 16 and 31oC, 16 and 36oC, and 16 and 34oC, respectively. The lower developmental thresholds and degree-days(DD) were determined as 13.0oC and 56.9DD, 13.8oC and 277.5DD, and 14.2oC and 90.8DD using a linear regression model between temperature and development rate. Other parameters for explaining development of this species were estimated using a few non-linear models for developmental rate, distribution, and survivorship.
        64.
        2019.04 구독 인증기관·개인회원 무료
        Ostrinia scapulalis (Lepidoptera: Crambidae) overwinters as a final instar larva. In order to elucidate phenology of the insect, we studied several factors related to its overwintering. Neonate larvae from early August to early October entered overwintering through outdoor rearing. Pupation and adult emergence were observed during the periods from May to June, next year, and from May to July, respectively. Heat addition by 25oC to overwintering larvae induced shorter prepupal periods with progressing season. Supercooling points of overwintering larvae during the period from October to April were below -20oC, and those temperatures were significantly lower than those of a laboratory colony. It was estimated that higher content of glycerol in hemolymph is responsible for cold-hardiness as a cryoprotectant during overwintering.
        65.
        2019.04 구독 인증기관·개인회원 무료
        The Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae), produces final instar larvae of overwintering stage in response to decreasing day-length and temperature, and then those larvae pupate after about 6-8 month. In this study, we investigated a few properties related to cold hardiness during overwintering of the insect. Overwintering larvae collected in December could survive at least for 16 days at -20oC, while all larvae of a laboratory colony, which was reared at 25oC, 15L/9D, died within 2 hours. Supercooling points of overwintering larvae were below -20oC, and the temperatures were significantly lower than those (ca. -10oC) of the laboratory colony. It was estimated that higher content of hemolymph glycerol is responsible for cold-hardiness as a cryoprotectant during overwintering of O. furnacalis.
        66.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to determine the effects of hybrid and inoculant on in vitro rumen digestibility and rumen fermentation indices of corn silage. Two corn hybrids(Kwangpyeongok (KW) vs. Pioneer 1543(PI)) were ensiled for 100 days with two inoculants(L. plantarum(LP) vs. L. buchneri(LB)) applied at 1.2 × 105 cfu/g of fresh forage. Silages were incubated in rumen fluid medium at 39℃ for 72 hours. Both of KW and PI had no difference(p>0.05) on in vitro digestibility of dry matter(IVDMD) and neutral detergent fiber(IVNDFD), while application of LB produced higher(p<0.05) IVDMD and IVNDFD than LP. Hybrid and inoculant applications did not affect(p>0.05) total gas volume, ammonia-N, total VFA, and acetate concentrations in the rumen. Applied LB was higher(p<0.05) propionate concentration than LP, while hybrids had no effect(p>0.05). Furthermore, the interaction effect(p<0.05) was occurred in propionate concentration. Butyrate concentration did not affected(p>0.05) by hybrid and inoculant applications, but there was an interaction effect between hybrid and inoculant(p<0.05). Applications of hybrid and inoculant had effects(p<0.05) on iso-butyrate and valerate, without any interaction effects(p>0.05). This study concluded that application of KW and PI has no effects on in vitro rumen digestibility and rumen fermentation indices of corn silage, while application of LB increase the rumen digestibility in both of corn hybrids.
        4,000원
        67.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to examine the effect of new inoculants on in vitro digestibility and fermentation characteristics of high moisture rye silage. Rye was harvested at heading stage and divided into 5 treatments, following: No additives(CON); L. plantarum R48-27(NI1); L. buchneri R4-26(NI2); mixture of NI1 and NI2 at 1:1 ratio(MIX); and L. buchneri(LB). The rye forage was ensiled into 10 L bucket silo for 100 days. In vitro digestibility of dry matter and neutral detergent fiber were highest(p<0.05) in NI2 silage. The pH in NI2 and LB silages were lower(p<0.05) than CON silage. Lactate concentration was highest(p<0.05) in NI1 silage. While concentrations of acetate and propionate were highest(p<0.05) in MIX silage. Lactates : acetate ratio was highest(p<0.05) in NI1 silage, but lowest in LB silage. Butyrate concentrations of NI2 and LB silages were lower(p<0.05) than that in CON and NI1 silages. Lactic acid bacteria (LAB) count in all inoculated silages was higher(p<0.05) than that in CON silage, while yeast count in LB silage was lower than in CON, NI1, and MIX silages. In conclusion, application of NI2 inoculant could improve potentially fermentation quality and digestibility of high moisture rye silage.
        4,000원
        68.
        2018.10 구독 인증기관·개인회원 무료
        과일이나 농작물의 부패 및 발효 환경에서는 Methanol, Ethanol, Acetic acid을 비롯한 다양한 화학물질들이 생산된다. Drosophila melanogaster는 이러한 발효·부패 환경에 서식하면서 일정 농도 이상의 다양한 화학물질에 지속적으로 노출되어 생존하도록 적응되어온 것으로 생각된다. 다양한 화학물질이 포함한 환경에 안정적으로 서식하기 위해서는 D. melanogaster는 화학물질에 능동적으로 반응하여 해독 유전자나 대사 관련 유전자의 발현량을 변화 시킴으로써 발효·부패 환경에서 생성되는 화학물질에 대한 높은 내성을 가지고 있을 것으로 판단된다. 현재까지 유전자의 발현량 측정을 위해 real-time PCR를 이용하여 reference gene의 발현량을 기준으로 정량화하는 방법이 가장 널리 사용되고 있다. 그러나 조직별, 환경별, 발달단계를 비롯한 다양한 조건에서 안정적으로 발현되는 reference 유전자 선정이 필수적으로 선행되어야 하므로 본 연구에서는 발효·부패 환경에서 생산되는 두 화학물질인 Methanol과 Ethyl Acetate에 노출된 D. melanogaster에서 안정적으로 발현되는 reference gene을 찾는 연구를 실시하였다. 본 연구에서는 다양한 농도의 Methanol과 Ethyl Acetate을 D. melanogaster에 노출시킨 후 RNA 추출과 cDNA 합성을 실시였고, 5가지 후보 reference gene (hsp22, nd, rpL18, tbp and ef-1b)의 안정적 발현 여부를 qRT-PCR을 통해 조사하였으며, 유전자 발현의 안정성을 측정하는 3가지 프로그램(geNorm, NormFinder, BestKeeper)을 이용해 비교·분석하였다. 본 학회에서는 연구의 과정과 그 결과를 발표하고자 한다.
        70.
        2018.05 구독 인증기관·개인회원 무료
        The composition of the deicer sprayed on the highway is spreading over the highway by the scattering or snow removal activity, or car movement and consequently affecting the vegetation environment around the highway. These are the cause of the damage of fruit trees and crops, and also the cause of corrosion of highway structures. The goal of this study is to estimate the detected range of deicer components from a highway. The concentration of the deicer components in gauze and soil were investigated according to the crossing distance from the highway. The data collected were then used to estimate the concentration range of deicer components in a rage of distance up to 100 m from the highway where the deicer was spread. The sample time and weight of gauze were measured before and after installation, and the soil was collected at more than three points in parallel with the highway at the gauze installation point. The components in gauze and soil were investigated in addition to the deicer components (Ca2+, Na+, Cl-) as well as Mg2+ and K+. As Ca2+ and Cl- components of deicer were affected by agricultural use, Na+ component was selected as a tracer and further SAR (Sodium Adsorption Ratio) of soil was analyzed to examine the degree of influence on vegetation indirectly. The gauze concentration was evaluated by the concentration of the deicer ingredient at the background concentration of the blank gauze. The total amount of the deicer sprayed in the study road for 4 months (winter season) was about 93 ton/km. In the gauze test, the spread of the deicer was detected at a distance of 100 m in study area, but the concentration of the deicer in the gauze by distance decreased rapidly within 10 m from the highway. And concentration of the deicer components in gauze and soil came down after rainy season (August ~ Sep.). The results showed that the components of the deicer could be spread widely by the wind. The effective range of the deicer on vegetation based on SAR in soil was estimated to be less than 20 m from the highway. This study examines the concentration changes of the deicer components in gauze and soils and shows that deicer components sprayed on the highway are accumulated and moved over time by wind, snow removal, terrain, water system and land use around the highway.
        72.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to estimate the effect of home or hetero fermentative lactic acid bacteria(LAB) on chemical composition, fermentation quality, and aerobic stability of rye silage. Rye forage was harvested at dough stage(28.9% of dry matter), chopped to 3-5 cm length, and divided into 4 piles for different inoculations as treatment, following 1) No additives(CON); 2) Lactobacillus plantarum at rate of 1.5 x 105 cfu/g of fresh forage(LP); 3) L. buchneri at rate of 1.2 x 105 cfu/g of fresh forage(LB); and 4) Mixture of LP and LB at 1:1 ratio(MIX). Rye silage was ensiled into 20 L bucket silo in quadruplicate for 0, 1, 4, 7, and 100 day periods. After 100 days of ensiling, the silage treated with LB had lower acid detergent fiber content(p<0.05), but higher in vitro dry matter digestibility(p<0.05). The LB and MIX reduced (p<0.05) pH more rapidly than CON and LP across the ensiling days, but had no difference on 100 days. Silage treated LP had lowest(p<0.05) acetic acid, but highest(p<0.05) propionic acid. In contrast, LB treated silage had highest(p<0.05) acetic acid, but lowest(p<0.05) propionic acid with the absence of butyric acid. On microbial count, LP treated silage had lowest(p<0.05) LAB, yeast, and aerobic stability, whereas LB and MIX treated silages had highest(p<0.05). Mold was not detected across all silages. Therefore, it could be concluded that heterofermentative LAB solely or combo with homofermentative LAB might improve in vitro dry matter digestibility, fermentation characteristics, and aerobic stability of rye silage harvested at dough stage.
        4,000원
        73.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite resins are developed as restorative materials to improve esthetics and mechanical properties. To improve the physical properties of resin material, resin filler have to be added. However, no imaging method is adopted for resin filler distribution. Optical coherence tomography (OCT) is a optical imaging technique to delineate microscopic structures within biological tissue. The OCT application to dental composites resin and its filler is not described yet. So, this new and advanced optical method is needed for clinical application for evaluation of dental composite resin. To analyze the spatial distribution of dental composite resin and to evaluate the resin restoration in cavity, frequency domain optical coherence tomography (FD-OCT) was used for their analysis. Resin restored tooth was prepared. For morphological observation, serially sectioned teeth, conventional X-ray taking and micro computed-tomography (CT) images were compared with OCT images. The experiment has done to evaluate the success of the resin restoration using 3 dimensional structure OCT image. In this research, OCT is evaluated as a new technique to image resin restoration. The evaluation of resin restored tooth was performed by OCT. Inappropriate restoration such as marginal adaptation, large porosities, internal integrity and poor contour could be detected. Resin filler also could be checked by OCT. The distribution, number, regularity and size of resin filler can be differentiated from several commercial products. Considering the characteristics of the OCT, it can be used to evaluate the defects of resin restoration, resin filler distribution, and internal integrity between resin material and tooth structure. The OCT can be considered to be a new and advanced method for the evaluation of resin restorations.
        4,000원
        74.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to review speaking articles published in the journal of English Teaching over the past 50 years. A total of 145 speaking articles were analyzed according to research areas, target groups, language and research methodologies for every ten years from 1965 to 2015. A thematic analysis was also conducted based on eleven major research categories. The results showed that a shift of focus in research themes occurred around the fourth decade ofthe journal between 1995 and 2004 with a surge in the amount of speaking articles, greater attention of which was paid to methods and approaches, i.e., specific classroom-oriented tasks and activities to improve students' oral proficiency. While oral assessment was the second most productive area of research topics, the number of studies on materials and media ranked third, due to the trend in computer-assisted language learning in the last two decades. Research methodologies were evenly divided among theoretical, quantitative, qualitative, and alternative types, although the recent two decades have witnessed a noticeable increase in the number of quantitative analyses based on survey and experimental studies and qualitative studies on classroom discourse and native versus non-native interaction. Implications and future directions are suggested.
        7,000원
        75.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Subcutaneous emphysema is a rare but serious side effect of dental and oral surgery procedures. The condition is characterized by air being forced underneath the tissue, leading to swelling, crepitus on palpation, and with potential to spread along the fascial planes to the periorbital, mediastinal, pericardial, and/or thoracic spaces. A wide range of causes have been documented for the origin of subcutaneous emphysema during dental treatment including: crown preparations, other operative procedures, endodontic therapy, extractions, as well as oral surgery procedures. The patient was a 58-year-old woman who presented to the Seoul Saint mary’s hospital emergency department with a chief complaint of facial edema, dyspnea and chest discomfort after periodontal treatment using an air-flow equipment in local dental clinic. During treatment in the emergency department, oxygen therapy and intravenous injection of steroid and anti-histamine was done. it was noted that the patient had pain and swelling on left lower molar region, pus discharging on same site. Severe edema was observed on periorbital region to neck with heatness. An audible crepitus sound was heard during palpation on facial area. Neck CT scan and antibiotic therapy was done, as symptom suggesting dental abscess is observed. 3 hours after injection of antibiotics, the patient’s symptom was relieved, but she felt chest discomfort continuously. CT scan with constrast depicted confluent and extensive soft tissue emphysematous changes involving face and deep neck spaces and pneumomediastinum. The patient was refered to thoracic surgery department, oxygen therapy was decided continuously. After 10 hours, patient’s chief complaint was resolved, and discharged. After 1 week, all symptom was disappear and follow-up neck CT scan finding was disappearance of edema and pnuemomediastinum. We report a case of cervical subcutaneous emphysema and pneumomediastinum occurring after periodontal treatment using an air-flow equipment and case on the diagnosis and treatment of subcutaneous emphysema and pneumomediastinum, along with a review of the literature.
        4,000원
        76.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sesame is a major cooking oil crop in Korea. One of the primary problems in sesame cultivation is low healthy stand establishment due to the occurrence of seedling rot and damping-off resulting from a complex of soil-borne pathogens in the field. To address the problem, the bioformulation of Pseudomonas fluorescens M45 was prepared in powder form using clay and vermiculite, and was evaluated for its effect on biological control of soil-borne pathogens in sesame cultivation. In the petri dish trial, the emergence rate was overall good (> 92%) regardless of seeds being pelleted and/or M45-treated. In both pot and field trials containing disease-conducive soils, seed-pelleting substantially reduced emergence rate, whereas seed-pelleting with M45 significantly improved the emergence rate (> 26%). The emergence rate of sesame seeds treated with the strain M45 was greater than 30% regardless of seed pelletization. We also found that M45r colonized in the roots at the density of 1.6×105 cfu/g. With aid of the bioformulation, however, root colonization of the strain was significantly increased to 4.0×106 cfu/g. The powder formulation with strain M45 enhanced the rate of healthy stand establishment in disease-conducive soil. Therefore, bioformulation with strain M45 is a promising method to overcome problems associated with the successive cultivation of sesame.
        4,000원
        78.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 환경스트레스 저항성이 증진된 페튜니아를 개발하기 위하여 NDPK2유전자 도입 형질전환 계통 NDPK2-7-1와 SOD2 유전자 도입 형질전환 계통 SOD2- 2-1-1-35간의 교잡에 의해 획득된 후대들의 비생물적 스트레스 저항성을 조사하기 위해 수행되었다. 비 생물적 스트레스 유발원인 메틸바이올로젠(methyl viologen, MV) 100 μM과 200 μM 처리에서 교잡후대들은 그들의 교배 모본 SOD2 유전자나 NDPK2 유전자가 단독으로 도 입된 형질전환 계통이나 비형질전환체 보다 메틸바이 올로젠에 의한 피해를 적게 받았다. 이는 SOD2 유전 자나 NDPK2 유전자가 단독으로 도입된 형질전환 계 통간 교잡에 의해 획득된 후대들이 그들의 교배모본 (SOD2 유전자나 NDPK2 유전자가 단독으로 도입된 형질전환 계통)이나 비형질전환체 보다 산화적 스트레 스에 대한 저항성이 증진되었음을 증명해 준다고 할 수 있다. 이들 교잡후대들은 초장 등 11종류의 양적형질의 특성이 비형질전환체에 비해 약간 길거나 짧긴 하였지 만 비형질전환체와 거의 유사하였으며, 꽃 색갈이나 모양 또한 그들의 교배모본 (SOD2 유전자나 NDPK2 유전 자가 단독으로 도입된 형질전환 계통)이나 비형질전환 체와 차이가 없었다.
        4,000원
        79.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA) 가지형 공중합체를 합성한 후, 이를 이용하여 80℃에서 열적으로 환원하여 은 나노입자를 제조하였다. 반응 시간을 바꿈에 따라 다양한 구조의 은 나노입자를 제조하는데 성공하였다. 1시간 정도의 짧은 반응 시간에서는 가지형 공중합체의 미세 상분리 구조를 크게 변화시키지 않고 5 nm 크기의 작은 은 나노입자가 생성되었다. 5시간 정도의 중간 반응 시간에서는 30 내지 50 nm 정도의 크기를 갖는 은 나노입자가 생성되었다. 18시간 정도의 긴 반응 시간에서는, 은입자가 뭉친 허리케인 모양의 은 집합체가 관찰되었다.
        3,000원
        80.
        2008.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have investigated the optical properties of the global haze on Titan from spectra recorded between 7100 and 9200Åwhere CH4 absorption bands of various intensities occur. The Titan spectra were obtained on Feb. 23, 2005 (UT), near the times of the Cassini T3 flyby and Huygens probe, using an optical echelle spectrograph (BOES) on the 1.8-m telescope at Bohyunsan Observatory in Korea. In order to derive the optical properties of the haze as a function of altitude, we developed an inversion radiative-transfer program using an atmospheric model of Titan and laboratory CH4 absorption coefficients available from the literature. The derived extinction coefficients of the haze increase toward the surface, and the coefficients at shorter wavelengths are greater than those at longer wavelengths for the 30 - 120 km altitude range, indicating that the Titanian haze becomes optically thin toward the longer wavelength range. Total optical depths of the haze are estimated to be 1.4 and 1.2 for the 7270 -7360Åand 8940 -9150Å ranges, respectively. Based on the Huygens/DISR data set, Tomasko et al. (2005) reported total optical depths of 2.5 - 3.5 at 8290Å depending on the assumed fractal aggregate particle model. The total optical depths based on our results are smaller than those of Tomasko et al., but they partially overlap with their results if we consider a large uncertainty from possible variations of the CH4 mixing ratio over Titan's disk. We also derived the single scattering albedo of the haze particles as a function of altitude: it is less than 0.5 at altitudes higher than ~150Km the average particle radius is smaller than the wavelengths, whereas near the surface, it becomes comparable or greater.
        4,300원
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