검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 819

        321.
        2017.10 구독 인증기관·개인회원 무료
        The diamondback moth, Plutella xylostella is one of the world’s major pests. Economic cost to control this pest wasestimated between US$1.3 billion and US$2.3 billion based on management costs. Conservative estimate included yieldloss caused by 5% diamondback moth was estimated US$4 billion-US$5 billion. P. xylostella was managed by chemicalinsecticide such as organophosphates, carbamates and pyrethroids. But insecticide resistance which is caused by repeatedapplication makes it difficult to control this pest. For environmental friendly control of diamondback moth, entomopathogenicfungi could be used as alternative. We conducted bioassay to select high virulent isolate to larva of diamondback mothwith forty six entomopathogenic fungi which were isolated from soil samples by insect-bait method. As a result of bioassaytwelve isolates was selected as candidate. We investigated control efficacy of these twelve isolates with potted Chinesecabbage at laboratory and greenhouse.
        322.
        2017.10 구독 인증기관·개인회원 무료
        A new commercial cultivar ‘GARES-HM-17-1’ of Hypsizigus marmoreus was developed by the method of mono-mono crossing between monokaryotic strains derived from Hae-Sal 3Ho. The parental strains are characterized by the property of high quality and a short period of time in cultivation. The optimum temperature of mycelial growth was 25°C and that of fruiting body development was 15~16°C. The period of harvesting including primordia formation was 23.0 days shorter than that of control strain Mangadak No. 2. The color of pileus and stipe surface was neutral-white, respectively. The yield was 82.0±5.8g/850cc plastic bottle. Analysis of the genetic characteristics of the new commercial cultivar ‘GARES-HM-17-1’ showed a different profile as that of the control strain, Mangadak No.2, when RAPD (Random Amplified Polymorphic DNA) primer was used. This new cultivar ‘GARES-HM-17-1’ of H. marmoreus is characterized by the improved quality and a short period of time in cultivation after scratching. It would be of much help to expand the cultivation area of H. marmoreus.
        323.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to quantify and characterize the inorganic nitrogen and phosphorus outflow loading from different water managements in paddy fields. We investigated the NO3-N, NH4-N, and PO4 in runoff from paddy fields in Iksan. The three different water management treatments were conventional continuous irrigation at 4 and 8 cm water levels, and intermittent irrigation at a 4 cm water level. The concentration of NO3-N at the early growth stage in surface water was 6.11 mg L-1, and then it gradually decreased. The downward curve increased slightly with additional nitrogen fertilization at the panicle initiation stage, and then it continued to decrease. The NH4-N concentration was 5.26 mg L-1, and that of PO4 was 0.70 mg L-1 at the early growth stage. However, the concentration of NO3-N peaked at 8.79 mg L-1 directly after transplantation and then decreased rapidly throughout the growing season. The amount of NH4-N runoff was 1.86 kg ha-1 in the plot with intermittent irrigation, and 2.0 kg ha-1 and 2.1 kg ha-1 in the plots with water depths of 4 and 8 cm, respectively. The NO3-N runoff was 7.43 kg ha-1 in the plot with intermittent irrigation, 8.62 kg ha-1 in the plot with a water depth of 4 cm, and 10.25 kg ha-1 in the plot with a water depth of 8 cm. In addition, the PO4 runoff was 0.42 kg ha-1 in the plot with intermittent irrigation, 0.48 and 0.55 kg ha-1 in the plots with water depths of 4 and 8 cm, respectively. The saving effect of irrigation water was 28.5% than that of conventional water management treatments, and the amount of nitrogen runoff was decreased by 18.5% with intermittent irrigation. However, the phosphorus runoff was not different between the different water management treatments in paddy fields.
        4,000원
        324.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Samples were collected between August 2016 and May 2017 at Sangju-si, Gyeongsangbuk- do, Jeju-do, and Uljin-gun, Gangwon-do. As a result, one genus and six species were newly recorded in Korea. The unrecorded indigenous genus was Borzia, and the six species were Anagnostidinema acutissimum, Komvophoron bourrellyi, Hydrocoleum stankovicii, Borzia trilocularis, Phormidium tinctorium and Pseudanabaena lohchoides. Phormidium tinctorium and Pseudanabaena lohchoides had been reported to inhabit freshwater, but in this study, these were found in brackish water. It had also been reported that B. trilocularis trichomes are composed of up to 8 cells, but in this study, a maximum of 10 cells was observed.
        4,000원
        325.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) is an upstream signaling molecule that has been shown to induce stress tolerance in plants. In this study, the AtNDPK2 gene, under the control of a stress-inducible SWPA2 promoter, was introduced into the genome of tall fescue (Festuca arundinacea Schreb.) plants. The induction of the transgene expression mediated by methyl viologen (MV) and NaCl treatments were confirmed by RT-PCR and northern blot analysis, respectively. Under salt stress treatment, the transgenic tall fescue plants (SN) exhibited lower level of H2O2 and lipid peroxidation accumulations than the non-transgenic (NT) plants. The transgenic tall fescue plants also showed higher level of NDPK enzyme activity compared to NT plants. The SN plants were survived at 300 mM NaCl treatment, whereas the NT plants were severely affected. These results indicate that stress-inducible overexpression of AtNDPK2 might efficiently confer the salt stress tolerance in tall fescue plants.
        4,000원
        326.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A study on indigenous diatoms was carried out at 10 sites from May 2014 to December 2016 in marine and freshwater in Korea. Seventeen species of diatoms are new to Korea and they are divided into 3 classes, 4 subclasses, 10 orders, 14 families, and 16 genera. The nomenclatures, references, dimensions, specimens examined, local habitat, distribution in Korea, and photograph are reported here. Seventeen species found in marine, freshwater, and brackish water showed species-specific habitats.
        4,300원
        327.
        2017.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The emergence of antimicrobial resistant Escherichia (E.) coli is a major problem in pig farms. To tackle this issue, in July 2011, the Korean government banned the use of antimicrobials for growth promotion of animals in farms. Moreover, E. coli encoding the Stx2e gene cause edema disease which results in high mortality and morbidity in pig farms. Therefore, the aim of this study was to investigate the prevalence of antimicrobial resistance among E. coli encoding the Stx2e gene isolated from weaned piglets with diarrhea before and after the ban on antibiotic growth promoters (AGPs) in Korea from 2007 to 2016. In this period, 479 E. coli isolates were obtained from weaned piglets with diarrhea, and of them, 144 E. coli isolates encoding the Stx2e gene were detected by polymerase chain reaction. The susceptibility of the E. coli isolates to antibiotics were tested using the standard Kirby-Bauer disk diffusion method. The most frequently observed resistances in isolates obtained from weaned piglets in the last 10 years were to tetracycline (92.4%) and chloramphenicol (88.9%). The prevalence of resistance to colistin (3.1% to 16.5%) and tetracycline (86.2% to 97.5%) was also observed to have increased over this period. Additionally, multi-drug resistance was also found to have increased (87.7% to 97.5%) after the ban on AGPs. These findings provide useful data for designing prevention and treatment strategies for postweaning diarrhea and edema disease, and can be used in future studies on antimicrobial resistance in Korea.
        4,000원
        328.
        2017.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this work, the effects of hydrogen reduction on the microstructure and thermoelectric properties of (GeTe)0.85(AgSbTe2)0.15 (TAGS-85) were studied by a combination of gas atomization and spark plasma sintering. The crystal structure and microstructure of TAGS-85 were characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM). The oxygen content of both powders and bulk samples were found to decrease with increasing reduction temperature. The grain size gradually increased with increasing reduction temperature due to adhesion of fine grains in a temperature range of 350 to 450 °C. The electrical resistivity was found to increase with reduction temperature due to a decrease in carrier concentration. The Seebeck coefficient decreased with increasing reduction temperature and was in good agreement with the carrier concentration and carrier mobility. The maximum power factor, 3.3 × 10−3 W/mK2, was measured for the non-reduction bulk TAGS-85 at 450 °C.
        4,000원
        329.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lithium silicate, a lithium-ion conducting ceramic, is coated on a layer-structured lithium nickel manganese oxide (LiNi0.7Mn0.3O2). Residual lithium compounds (Li2CO3 and LiOH) on the surface of the cathode material and SiO2 derived from tetraethylorthosilicate are used as lithium and silicon sources, respectively. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy analyses show that lithium silicate is coated uniformly on the cathode particles. Charge and discharge tests of the samples show that the coating can enhance the rate capability and cycle life performance. The improvements are attributed to the reduced interfacial resistance originating from suppression of solid-electrolyte interface (SEI) formation and dissolution of Ni and Mn due to the coating. An X-ray photoelectron spectroscopy study of the cycled electrodes shows that nickel oxide and manganese oxide particles are formed on the surface of the electrode and that greater decomposition of the electrolyte occurs for the bare sample, which confirms the assumption that SEI formation and Ni and Mn dissolution can be reduced using the coating process.
        4,000원
        330.
        2017.04 구독 인증기관·개인회원 무료
        Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.
        331.
        2017.04 구독 인증기관·개인회원 무료
        It has been proved that agroinfiltration-based temporary expression of coatomer subunit alpha (COPA) gene from Tetranychus urticae hairpin RNA induces RNA interference (RNAi) and lethality to T. urticae. To establish detailed protocols for agroinfiltration, the efficiency of agroinfiltration to the soybean and kidney bean was determined with respect to different Agrobacterium delivery methods (sea sand, carborundum and syringe) and the spacial expression patterns of hairpin RNA was investigated following Agrobacterium delivery. Sea sand and syringe showed the highest expression level in soybean and kidney bean, respectively. Considering the resulting tissue damage, syringe appeared the best choice for agroinfiltration in both soybean and kidney bean. The apical region of a leaf showed more relative expression levels in both soybean and kidney bean compared to the basal region. Following agroinfiltration, adjacent untreated leaves were determined to express hairpin RNA though the expression level was low, suggesting that hairpin RNA can be translocated to other leaves. In conclusion, Agrobacterium delivery by syringe and use of whole leaf were recommended for T. urticae bioassay following agroinfiltration.
        332.
        2017.04 구독 인증기관·개인회원 무료
        The toxicity of neem extracts that induce abnormality and lethality is strongly enhanced by the ingestion rather than surface contact. Oral toxicity of neem extracts was analyzed using a plant sapping pest Bemisia tabaci. When adults were allowed to ingest various doses (0, 5, 10, and 50 ppm) of azadirachtin diluted in 20% sugar solution in a double-layered parafilm chamber for 72 h, mortality was 12.5, 77.5, 97.5, 100%, respectively. When a cucumber leaf which has many nymphs were submerged into the solution of neem extract, adult eclosion was decreased to 87.0, 16.6, 16.1, and 6.6%, respectively. Further, when neem extracts were irrigated into the tomato cultivar the average number of nymphs per leaf was decreased to 60.3% in comparison with the untreated control. These result suggest that systemic treatment of neem extracts was effective for the control of whiteflies as well as other sucking insect pests.
        333.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Our understanding of dust emission, interaction, and evolution, is evolving. In recent years, electric dipole emission by spinning dust has been suggested to explain the anomalous microwave excess (AME), appearing between 10 and 90 Ghz. The observed frequencies suggest that spinning grains should be on the order of 10nm in size, hinting at polycyclic aromatic hydrocarbon molecules (PAHs). We present data from the AKARI/Infrared Camera (IRC) due to its high sensitivity to the PAH bands. By inspecting the IRC data for a few AME regions, we nd a preliminary indication that regions well- tted by a spinning- dust model have a higher 9 m than 18 m intensity vs. non-spinning-dust regions. Ongoing e orts to improve the analysis by using DustEM and including data from the AKARI Far Infrared Surveyor (FIS), IRAS, and Planck High Frequency Instrument (HFI) are described.
        3,000원
        334.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A total of nine Korean indigenous goats were used in a cross-over arrangement to give nine replicates per treatment, and they were housed individually assigned to 1 of 9 dietary treatments. Nine treatments were 0, 500, and 1000 ppm of quercetin supplementation in diets by mixing roughage and concentrate with different ratios (RC ratio) of 3:7 (RC 30), 5:5 (RC 50) and 7:3 (RC 70). Nutrient utilizations of dry matter, crude fat and NDF were not affected by neither RC ratio nor dietary quercetin (p>0.05), but the rate of crude protein and ADF increased in animals in RC 70 group regardless of quercetin supplementation (p<0.05). In addition, higher RC ratio increased (p<0.05) N retention and N retention rate. Total VFA, acetic acid, propionic acid, iso-butyric acid, butyric acid, iso-valeric acid and valeric acid contents were not affected (p>0.05) by dietary quercetin. Meanwhile, lower total cholesterol level exhibited in animals in RC 70 group compared to RC 30 or 50 groups, unrelated to dietary quercetin (p<0.05), however other plasma parameters were not influenced (p>0.05) by RC ratio and dietary quercetin. Our results indicated that both RC ratio and dietary quercetin may not directly affect the production indices and immune responses in Korean indigenous goat
        4,000원
        335.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There are studies on the assessment of non-edible transgenic plants on soil microbial communities. In this research we evaluated the effect of virus-resistant trigonal cactus on soil microbial communities of the rhizosphere. Soil samples are collected and compared in genetically modified (GM) and non-GM trigonal cactus cultivation fields during vegetative growth period and post-harvest period. Biolog EcoplateTM was used to evaluate the functional diversity of soil microbial communities. There were no significant differences between the GM and non-GM soil samples collected during the vegetative growth period. However, we observed temporary difference in carbon substrate utilization. Principal component analysis showed that soil microbiota was influenced not by presence of GM or non-GM trigonal cacti, but rather by the cultivation period. Denaturing gradient gel electrophoresis fingerprinting revealed that virus-resistant trigonal cactus cultivation had insignificant effect on soil microbial communities including dominant rhizosphere bacteria, actinomycetes, and fungi. We found no clear evidence of GM trigonal cactus cultivation affecting the functional diversity of soil microbial communities.
        4,000원
        336.
        2016.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        La1-xBaxMnO3 (x = 0.30, 0.35 and 0.40) samples have been prepared by solid-state reaction method. The X-ray diffraction (XRD) study showed that all the samples crystallized in a rhombohedral structure with an R-3c space group. Variation of the magnetization as a function of the temperature and applied magnetic field was carried out. All the samples revealed ferromagnetic to paramagnetic (FM-PM) phase transition at the Curie temperature TC ~ 342 K. The magnetic entropy change was also studied through examination of the measured magnetic isotherms M(H, T) near TC. The magnetocaloric effect was calculated in terms of the isothermal magnetic entropy change. The maximum entropy change reaches a value of 1.192 J/ kgK under a magnetic field change of 2.5T for the La0.6Ba0.4MnO3 composition. The relative cooling power (RCP) is 79.31 J/ kg for the same applied magnetic field.
        4,000원