검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 1,217

        261.
        2019.08 구독 인증기관 무료, 개인회원 유료
        This study is exploratory research on a relationship between changes in cultivated area of major crops and farm income by regions. We investigated level of income, volatility of income, and migration of suitable region by climate changes as factors influencing changes in cultivated area. Research processes are as follows. First, we classify the regions where cultivated areas are expanded or reduced through the trends of cultivated area by region and crop during recent 10 years. Second, we compare the changes in income related factors between groups during the same periods. Finally, the results from portfolio analysis show changes in stable income-based optimal crops. From these procedures, we found that the changes in cultivated area are not simply explained by income-related factors. In cases of vegetables, however, we also found that high volatility of income could contribute to reduce cultivated area of the crops. The results from portfolio analysis are not always consistent in all of cases. This means that crop selection can be decided by other factors than stable income.
        5,100원
        268.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Leuconostoc spp. are generally utilized as kimchi starters, because these strains are expected to have beneficial effects on kimchi fermentation, including improvement of sensory characteristics. Here, we developed a detection method for verifying the presence of the kimchi starter Leuconostoc mesenteroides WiKim33, which is used for control of kimchi fermentation. A primer set for multiplex polymerase chain reaction was designed based on the nucleotide sequence of the plasmids in strain WiKim33, and their specificity was validated against 45 different strains of Leuconostoc spp. and 30 other strains. Furthermore, the starter strain consistently tested positive, regardless of the presence of other bacterial species in starter kimchi during the fermentation period. Our findings showed that application of a strain-specific primer set for strain WiKim33 presented a rapid, sensitive, and specific method for detection of this kimchi starter strain during natural kimchi fermentation.
        4,000원
        269.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pitch precursors affording excellent spinnability, high-level oxidation-resistance, and good carbonization yields were prepared by bromination–dehydrobromination of various ratios of pyrolyzed fuel oil and coal tar pitch. The pitches exhibited spinnabilities that were much better than those of pitches prepared via simple distillation. A pitch prepared using a 1:2 ratio of fuel oil and coal tar pitch exhibited the best tensile strength. Pitch fibers of diameter 8.9 ± 0.1 μm were stabilized at 270 °C without soaking time after heating at a rate of 0.5 °C/min and carbonized at 1100 °C for 1 h after heating at 5 °C/min. The resulting carbon fibers exhibited a tensile strength, elongation, Young’s modulus, and average diameter of 1700 ± 170 MPa, 1.6 ± 0.1%, 106 ± 37 GPa, and 7.1 ± 0.2 μm, respectively.
        4,000원
        270.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Low cost and scalable manufacturing of highly doped cellulose for enhanced multifunctional applications is still an issue. In this work, eco-friendly nanocomposites were fabricated by incorporating regenerated cellulose (RC) of 10, 30, and 50 wt% into an exfoliated graphene nanoplatelets (GNPs), resulting in the intercalation of GnPs. The thermal and electrical properties of hybrid nanocomposites were investigated. The structural property was conducted through scanning electron microscope and X-ray diffraction analyses. Strong frequency-dependent dielectric response was found due to the change of the permittivity and the loss tangent of nanocomposites by different content of RC, which is associated with the polarizations behavior. Non-elastic relaxation at the GNPs–RC chains interfacial areas in an alternating field was identified as the main cause of polarization losses among others. Detailed ferroelectric measurements provided the evidence of the ideal resistive behavior of the nanocomposites, which are confirmed by the resistivity measurements along the out-of-plane direction of the nanocomposite sheets.
        4,000원
        274.
        2019.04 구독 인증기관·개인회원 무료
        To identify and compare the venom components and expression patterns of some bees/wasps, venom gland-specific transcriptome analyses were conducted for 14 Aculeate bees/wasps. Most of the allergens and pain-producing factors showed extremely high expression levels in social wasps, implying that social wasps have evolved to use venom to defend the colony against intruders. Acid phosphatase and tachykinin, which are known as allergens and neurotoxic peptides, were found with high frequencies in the venom glands of solitary wasps. This suggests that solitary wasps might use their venom for catching and preserving prey. In the venom glands of bumblebees, little or no transcripts of major allergens or pain producing factors were identified, implying that bumblebees venoms are relatively less toxic than those of social or solitary wasps. Taken together, the differential expression patterns of venom genes in some Aculeate bees/wasps implies that bees/wasps have unique groups of highly expressed venom components, which appear to have evolved in response to both ecological and behavioral influences.
        275.
        2019.04 구독 인증기관·개인회원 무료
        Insect killing fungus Beauveria bassiana has been widely studied as a biological control agent. However, many studies have been focused on lab or field-based management. Herein this work, comparison of three B. bassiana strains was investigated under a molecular level. The whole genome sequences of ERL836, JEF-007 were analyzed by PacBio (35.5 Mb of ERL836 and 36.5 Mb of JEF-007) and ARSEF2860 referenced from GenBank (33.7 Mb). To compare the three strains, virulence, thermotolerance and chemical resistance were assayed. The transcriptomes of non-infecting B. bassiana and infecting B. bassiana against western flower thrips were analyzed using RNA-seq. This work can provide that genome features, functions, morphology and gene expression could be different under the molecular level, even if in the same species.
        276.
        2019.04 구독 인증기관·개인회원 무료
        최근 안전한 먹거리에 대한 관심 제고와 고품질 대추 생산에 대한 관심 급증으로 친환경적인 해충방제법의 필요성이 높아지고 있다. 친환경적 해충방제를 위하여 비가림하우스 별 방충망을 설치하여 해충방제 효과와 과실 생육을 조사하였다. 시험에 사용된 방충방 규격은 각각 25, 18, 6mesh로 대추나무잎혹파리, 장님노린재, 복숭아심식나 방의 차단효과를 보았다. 대추나무잎혹파리의 경우 피해엽율이 1.2%, 10.8%, 14.3%, 무처리구는 15%였으며 장님노린 재의 경우 피해눈율이 6.9%, 5.8%, 20.41%, 28.2%였고, 심식나방은 피해과율이 0.0%, 1.0%, 0.0%, 32.0%로 나타났다. 방충망처리에 따른 대추생육은 처리구와 무처리구에서 차이가 거의 없었다. 대추재배농가의 방충망 도입이 해충 방제에 효과가 큰 것으로 판단되며 문제가 되고 있는 세가지 해충을 모두 방제하기 위해서는 25mesh로 처리하는 것이 가장 효과적인 것으로 판단된다.
        277.
        2019.04 구독 인증기관·개인회원 무료
        We monitored the population of Haemaphysalis longicornis, in Andong, Gyungbuk from April to November, 2018. Among total 2,994 ticks collected for 8 months, H. longicornis 1,677(56%), H. spp Larva 1,074(35.9%), H. flava 213(7.1%), Ixodes nipponensis 30(1.0%) were identified. In addition, considering the environment, 1,727(57.7%), 907(30.3%), 192(6.4%) and 168(5.6%) ticks were collected in the grassland, graves, copse, mountain path, respectively. In the pathogen diagnosis with PCR using SFTS virus specific primers, positive viruses were detected in H. longicornis, H. flava and H. spp from June to October. The minimum field infection rate of June, July, August, September and October were 0.4%, 0.8%, 1.2%, 0.8% and 2.3%. respectively.
        278.
        2019.04 구독 인증기관·개인회원 무료
        Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae) is a worldwide polyphagous pest. The management of this pest have mainly relied on chemical agents. However, the overuse is harmful to the environment and results in insects resistance. Therefore, alternative eco-friendly control methods that have different mode of action, such as biological control, are necessary to overcome the current issue. In this study, we isolated entomopathogenic fungi from Korean soil, and characterized them via morphological and molecular techniques and pathogenicity assay against Tenebrio molitor larvae. The isolated fungi were screened for virulence against T. palmi under laboratory conditions and the results were used to establish a thrips-pathogenic fungal library. The highly virulent isolates were selected and further characterized for optimum culture conditions and application as biopesticide in the field.
        279.
        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.
        280.
        2019.04 구독 인증기관·개인회원 무료
        Japanese pine sawyer, Monochamus alternatus, is the main pest that mediates pine wilt nematode, Bursaphelenchus xylophilus, that causes serious damage to pine forests. In this study, we studied the strategy to control M. alternatus using entomopathogenic fungi. The fungi were collected from soil by an insect-baiting method and two fungal isolates (Metarhizium anisopliae JEF-197 and JEF-279) showed high virulence against M. alternatus. The Metarhizium isolates were evaluated for insecticidal activity against M. alternatus by spray treatment on live pine trees and wintering trees, and the M. anisopliae JEF-197 showed high insecticidal activity. In addition, the interaction of fungi and M. alternatus were analyzed by RNA-seq. This result can contribute to the development of insect control agents using entomopathogenic fungi.