검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 875

        421.
        2013.10 구독 인증기관·개인회원 무료
        Black fungus gnats play an important role as the decomposers in the forest ecosystem. Their larvae live on various organic matters, and the subfamily Sciarinae, in particular, have restricted habitats that feed on dead woods in the deep forest. We compared the biodiversity of family Sciaridae from two different habitats, the clear-cutting area (CA) and the pitch pine forest (PF) by the emergence traps (ET) and the pitfall traps (PT) from May to October, 2010. A total of 12 species were reliably identified to the species among 19 unique taxa belonging to 9 genera 4 subfamilies from 716 collected black fungus gnats. Taxonomic studies show that Corynoptera bicuspidata (Lengersdorf, 1926) (200 individuals, 27.9 % of total) and Cory. sinedens Hippa, Vilkamaa & Heller, 2010 (74 individuals, 10.3 % of total) dominate in the PF and the CA, respectively. Species richness and abundance of CA is lower than those of PF. Any species of subfamily Sciarinae were not collected in the CA. These findings indicate that the biodiversity of Sciaridae was influenced by forest management such as clear cutting, which leads to the changes of canopy cover, dead woods and leaf litter layer.
        422.
        2013.10 구독 인증기관·개인회원 무료
        The genus Psallus Fieber, 1858 (Phylini) is the largest group, with twenty six described species in Korea (Duwal et al., 2012). Due to recent collection in 2013, three new species are recognized from Korea. All these species are described, with images of dorsal habitus and genital structures. A checklist of the East Asian species and geographic distribution of Psallus is revised.
        423.
        2013.10 구독 인증기관·개인회원 무료
        Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important insect pests in the world. In the present study, the taxonomic status of B. tabaci and the number of species consisting of the B. tabaci complex were determined based on 1059 COI sequences of B. tabaci and 509 COI sequences of 153 hemipteran species. The genetic divergence within B. tabaci was conspicuously higher (onaverage,11.1%) than interspecific genetic divergence within the respective genera of the 153 hemipteran species (on average, 6.5%). This result indicates that B. tabaci is composed of multiple biological species that may belong to different genera or subfamilies. The phylogenetic tree constructed based on 212 COI sequences without duplications revealed that the B. tabaci complex is composed of a total of 31 putative species, including a new species, JpL. However, genetic divergences within five species, Asia III, Asia II 7, Mediterranean, New world, and Sub Saharan Africa 1, were higher than 3.5%, which has previously been used as a threshold of genetic boundary in distinguishing species of the B. tabaci complex. These results suggest the necessity to redefine the threshold for species boundaries to best distinguish the constituent species in the B.tabaci complex.
        424.
        2013.10 구독 인증기관·개인회원 무료
        We conducted a investigation for dispersal ability of Aedes albopictus, a dengue vector mosquito, using mark-release-recapture method in Korea. A certain number of fluorescence marked Ae. albopictus was released in four different habitats – urban (Cheonan), suburban (Jochiwon), port (Pyeongtaek), and airport (Cheongju), and sticky traps and BG-traps were used to recapture the mosquito in designated time period. In case of urban and suburban areas, 100 sticky traps were used in 3-week period for both regions, and 19 BG-traps and 15 BG-traps were used in 36-hour period for urban and suburban areas respectively. Using sticky trap, 21 from 1,300 released mosquitoes (1.62%) were recaptured in urban area; while in suburban area, only 2 individuals (0.1%) were recaptured. Most of them were recaptured within 100m from releasing point and about 40% were within 20m distance. When BG-traps were used, 35 from 900 released mosquitoes (3.8%) were recaptured in urban area; while 26 mosquitoes (2.8%) were recaptured in suburban area. The maximum distance of dispersal was 200m in urban and 100m in suburban area, while most of them were recaptured in 50 ~ 80m range. In case of port and airport area, 15 and 10 BG-traps were used respectively to recapture 1,000 released mosquitoes in 5-day period. In port area, 23 mosquitoes (2.3%) were recaptured; while 166 mosquitoes (16.6%) were recaptured in airport area. The maximum distance of dispersal was 130m in both areas; while most of them were recaptured in 50m range. In conclusion, Ae. albopictus has a narrow dispersal range compared to other mosquitoes, a typical characteristic of genus Aedes, and their dispersal ability is greatly affected by various environmental factors. These results can provide basic information for effective prevention of Ae. albopictus and overseas inflow of dengue fever.
        425.
        2013.10 구독 인증기관·개인회원 무료
        The Cerambycidae is a very diverse family in Chrysomeloidea (Insecta: Coleoptera), and the members are commonly called as longhorn beetles, long-horned beetles or longicorn beetles. The family is comprised of approximately 25,000 described species in nine subfamilies worldwide, and 311 species are known from Korean insect fauna. Most species are associated with woods and shrubs or live on herbaceous vegetation in open areas. Cerambycid larvae are primarily borers in deadwood. Some species develop in living trees and cause damage on host plants by boring heart wood and making galleries. As the results of four year field surveys (from 2010 to 2013) and literature review, host plants of 181 species of Korean Cerambycidae are revised, including thirteen new cerambycid-host associations, and more than 179 host plants species of 107 genera in 44 families are compiled. Among them, most common host plants are belonged to mainly four families: Ulmaceae, Pinaceae, Fagaceae and Betulaceae. Additionally, Acer tegmentosum Maxim. (Aceraceae) is newly recognized as a host plant of the Asian longhorned beetle, Anoplophora grabripennis (Motchulsky) in South Korea.
        426.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Antibiotic Detection Kit (Combination I), a lateral flow immunoassay (LFIA) developed for the detection of antibiotic residues in milk, was utilized for the analysis of antibiotic residues in the muscle tissue of olive flounder. After 60-min treatment by dipping in water dosed with ampicillin (200-g/ton water), the residue depletion of ampicillin was investigated in 25 cultured olive flounder (Paralichthys olivaceus). Muscles of fish were sampled on the 1st, 2nd, 3rd, 4th and 5th day after drug treatment. The concentration of ampicillin in the muscle was determined by LFIA. The absorbance ratio of the sample to the control blank (Bs/Bo) was employed as an index to determine the muscle residues in olive flounder. To investigate the recovery rate, standard solutions were added to muscle samples to give final concentrations in the muscle of 4 and 8 ng/ml. The recovery rates of all spiked samples were > 96% of the spiked value. Ampicillin was detected in the muscle of fish treated with the drug until the 2nd day of the withdrawal period. The present study showed that the LFIA can be easily adopted to predict ampicillin residues in tissue of farmed fishes.
        3,000원
        427.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Needle coke is an important material for graphite electrodes. Delayed coking is used to produce needle coke. Producing good quality needle coke is not simple because it is a multi-parameter controlled process. Apart from that, it is important to understand the mechanism responsible for the delayed coking process, which involves mesophase formation and uniaxial rearrangement. Temperature and pressure need to be optimized for the different substances in every feedstock. Saturate hydrocarbon, aromatic, resin and asphaltene compounds are the main components in the delayed coking process for a low Coefficient Thermal Expansion value. In addition, heteroatoms, such as sulphur, oxygen, nitrogen and metal impurities, must be considered for a better graphitization process that prevents the puffing effect and produces better mesophase formation.
        4,000원
        428.
        2013.09 구독 인증기관 무료, 개인회원 유료
        Xylitol is a sugar alcohol with a variety of functions including bactericidal and anticariogenic effects. However, the cellular mechanisms underlying the role of xylitol in bone metabolism are not yet clarified. In our present study, we exploited the physiological role of xylitol on osteoclast dif-ferentiation in a co-culture system of osteoblastic and RAW 264.7 cells. Xylitol treatment of these co-cultures reduced the number of tartrate-resistant acid phosphatase (TRAP)- positive multinucleated cells induced by 10 nM 1α,25(OH)2 D3 in a dose‐dependent manner. A cell viability test revea-led no marked cellular damage by up to 100 mM of xylitol. Exposure of osteoblastic cells to xylitol decreased RANKL, but not OPG, mRNA expression in the presence of 10-8 M 1α,25(OH)2D3 in a dose‐dependent manner. Furthermore, bone resorption activity, assessed on bone slices in the co- culture system, was found to be dramatically decreased with increasing xylitol concentrations. RANKL and OPG proteins were assayed by ELISA and the soluble RANKL (sRANKL) concentration was decreased with an increased xylitol con-centration. In contrast, OPG was unaltered by any xylitol con-centration in this assay. These results indicate that xylitol inhibits 1α,25(OH)2D3-induced osteoclastogenesis by reducing the sRANKL/OPG expression ratio in osteoblastic cells.
        4,000원
        429.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chrysanthemum stunt viroid (CSVd) is a serious pathogen affecting chrysanthemum that has caused significant economic losses to Chrysanthemum flower production worldwide. Control of CSVd disease is difficult due to its contagious nature and long latent period in the field. As chrysanthemum is most often produced by implanting seedlings, it is necessary to diagnose CSVd infection before cultivation. In this study, we screened CSVd infection in seedlings from 30 varieties including 5 domestic, 6 Japanese, and 19 European varieties. Molecular diagnosis of the combination of RT-PCR and nested PCR showed that CSVd was not detected by the first RT-PCR but detected by the second nested PCR analysis in 10 varieties, including 1 domestic, 2 Japanese, and 7 European varieties. Further comparison of 10 identified CSVd nucleotide sequences showed that those are highly conserved (99-100%) and the most similar to an isolate (AB006737) identified in Hokkaido, Japan. Our study suggests that the combination of RT-PCR and nested PCR analysis is successful for the CSVd diagnosis of seedlings and the molecular diagnosis is necessary to prevent the introduction and propagation of viroid disease into the fields.
        4,000원
        431.
        2013.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We trace the dynamical evolution of dark matter (DM) content in NGC 6397, one of the native Galactic globular clusters (GCs). The relatively strong tidal field (Galactocentric radius of ~ 6 kpc) and short relaxation timescale (~ 0.3 Gyr) of the cluster can cause a significant amount of DM particles to evaporate from the cluster in the Hubble time. Thus, the cluster can initially contain a non-negligible amount of DM. Using the most advanced Fokker-Planck (FP) method, we calculate the dynamical evolution of GCs for numerous initial conditions to determine the maximum initial DM content in NGC 6397 that matches the present-day brightness and velocity dispersion profiles of the cluster. We find that the maximum allowed initial DM mass is slightly less than the initial stellar mass in the cluster. Our findings imply that NGC 6397 did not initially contain a significant amount of DM, and is similar to that of NGC 2419, the remotest and the most massive Galactic GC.
        4,000원
        433.
        2013.04 구독 인증기관·개인회원 무료
        Laos, a landlocked country in Southeast Asia, has most extensive network of ecosystems in the Indochina Peninsula, surrounded by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west. It is the tropical vegetation and warm climatic conditions influenced by monsoon. Such geographical and climatic condition is favorable for the diversity of insects. However, research or educative investigation on insects have been poorly conducted. Through recent expedition during dry season (between December 2012 and February 2013), mainly held at Phou Khao Khouay National Park (PKKNP), which varies from sheer sandstone cliffs and pristine river gorges to rough mountain slopes along the Mekong river, we recognized atotal of 88 lepidopteran insects belonging to 22 families, Arctidae, Attevidae, Choreutidae, Cossidae, Crambidae, Geometridae, Gracillariidae, Hesperidae, Hyblaeidae, Limacodidae, Lycaenidae, Lymantridae, Noctuidae, Nymphalidae, Oecophoridae, Papilionidae, Pieridae, Pyralidae, Scythrididae, Sphingidae, Uraniidae and Zygaenidae, were recognized.
        434.
        2013.04 구독 인증기관·개인회원 무료
        This study was carried out to clarify the response of butterfly communities on forest degradation in the Gwangneung Forest, Korea. We monitored butterfly communities with varying degrees of human activities by conducting line transect twice a month in 2011. A total of 70 species and 4,676 individuals butterflies were observed in four sites: natural forest, plantation forests, and Korean National Arboretum. Species richness increased with increasing open land. The result on niche breadth and habitat type of butterfly was consistent with our predictions; specialist species and forest interior species were abundant in natural forest, whereas generalist species and grassland species were abundant in Korea National Arboretum, the most modified area. Also, habitat breadth of butterflies clearly indicated the difference on the degree of forest degradation. Butterfly diversity associated with landscape patterns based on aerial photographs supported mosaic concept which indicates that species diversity increases as habitat heterogeneity and variability increase. Forest management plan that maintains various habitats and ensures grasslands is necessary to increase butterfly diversity in forest.
        435.
        2013.04 구독 인증기관·개인회원 무료
        The physiology of parasitic wasp control of their lepidopteran hosts' not only includes injecting their egg but also various factors such as symbiotic virus. This study was focused on the investigation of sophisticated interaction between parasitoid (Diadegma fenestrale) and their host (Plutella xylostella) in P. xylostella larva at transcriptome level, to check whether it is parasitized or not. Short-read deep sequencing method (Hiseq2000) was used for the transcriptome analysis. De novo assembly of cDNA sequence data generated 196,081 contigs between 201bp and 15,853bp in length. Some detoxification enzymes such as cytochrome P450 and Immune-related genes such as antimicrobial peptides were up-regulated after parasitism. Expression of symbiotic ichnovirus genes was detected in parasitized larvae with 55 contigs identified from five ichnovirus gene families including vankyrin, viral innexin, repeat elements, a cysteine-rich motif, and polar residue rich protein. This investigation provides a detailed information on differential expression of P. xylostella larval genes and symbiotic ichnovirus genes following parasitization.
        436.
        2013.04 구독 인증기관·개인회원 무료
        The synanthropic flies are regarded as the most important vectors of infectious diseases. Especially, feeding and reproductive habits make flies the important vectors of many pathogens such as malaria, yellow fever, dengue fever, typhoid fever, dysentery, and anthrax. Although most of lower flies (e.g. black-flies, mosquitos, sand-flies) transport diseases by bloodsucking, the mechanical dislodgment from exoskeleton is one of the important mechanisms of pathogens transmission for higher flies (Diptera: Brachycera) such as blow-flies, flesh-flies, and house-flies. According to recent phylogenetic studies, the Bibionomorpha is suggested as a sister taxon of the Brachycera as a monophyletic group “Neodiptera”. Coincidently, a part of black fungus gnats (Diptera: Bibionomorpha: Sciaridae) are known as the important vectors of fungal diseases on agricultural crops due to the spores carrying by there fore tibial structures. We propose that the correlation of spore carrying structures and habitats adaptation in the Sciaridae. The evolutionary pathway tests support that the fore tibia structures appeared first and followed by live plant habitats in the Sciaridae. Regarding analyses, we hypothesized that the evolutionary benefit of fungal carrying structures could be closely related with the larval habitats adaptation of Sciaridae. Interestingly, both adults of the synanthropic higher flies and the black fungus gnats are carrying various microorganisms by mechanical dislodgment from there tibial exoskeleton. The common habits of those flies could be providing clues about the evolution of the fly-microorganism interections.
        437.
        2013.03 구독 인증기관 무료, 개인회원 유료
        A 14-year-old female South American sea lion (Otaria byronia) with persistent vaginal secretion and chronic hemorrhagic diarrhea was encountered. During postmortem examination, the uterus was found to resemble a balloon with mucosal congestion and was filled with grayish milky material. The ovaries also had abnormal features, including necrotic surface lesions and multiple whitish foci in the cut section. Hemorrhages and ulcerated changes due to toxemia were observed in other organs, including the liver, spleen, lung, intestines, and lymph nodes. Microscopically, the left ovary contained interlacing fascicles of fibroblast-like cells with blunt-end nuclei showing cytoplasmic positive immunoreactivity against alpha-smooth muscle actin and desmin. The right ovary contained cells with round to cigar-shaped nuclei showing cytoplasmic positive immunoreactivity against vimentin. In conclusion, based on classification of bilateral ovarian tumors as a leiomyoma in the left region and a fibroma in the right region, this sea lion was diagnosed with chronic closed pyometra.
        3,000원
        438.
        2012.12 구독 인증기관 무료, 개인회원 유료
        Lactic acid bacteria (LAB) are known to promote activation of macrophages, selectively eliminate harmful intestinal bacteria that enter the body, and increase secretion of cytokines, chemokines, and inflammatory mediators that boost the immune system. In the current study, the immune-enhancing effects of five Leuconostoc stains (Leu. kimchii WK18, Leu. citreum DH33, Leu. mesenteroides DH34, SE34, and GY17) isolated from traditional Korean fermented food, Kimchi, were evaluated. Lactobacillus rhamnosus GG (LGG), which is known for its extraordinary immunopotentiating activity, was used as a reference strain. According to the results, several heat-killed Leuconostoc strains induced a higher level of NO, IL-1β, or TNF-α production than the LGG strain. Collectively, results of the current study suggest that Leuconostoc strains could enhance immune response through activation of macrophages, and could be significant references when verifying the possibility for use of Leuconostoc strains as probiotics, starter, dietary supplement, or immune-enhancing medicine.
        3,000원
        440.
        2012.10 구독 인증기관·개인회원 무료
        Honeybees (Apis mellifera) adapted themselves to different geographical and climatical conditions since they had been introduced in Korea. Beekeepers have tried to breed valuable lineages with artificial insemination or conventional mating techniques. However, evaluation of breeding resultants still relies on timeconsuming observation data. Genetical characterization of breeds has proven its usefulness to preserve genetic resources of livestock. In recent years, microsatellites are most commonly used to evaluate population structures and diversities of living organisms in that the characteristics of locus specificity, rich polymorphism, abundant and random distribution over the genome, and their co-dominant inheritance. Determining classic genetic distances using neutral, highly polymorphic microsatellite markers is a reliable method to investigate genetic relationships and breed differentiation. This methodology can be used to establish preservation priorities for livestock breeds. The final aim of this study was to develop potent markers for assessing genetic structure of lineages after artificial insemination. In this study, the genetic structure of ten microsatellite markers were sequenced or analysed with polymerase chain reaction for eleven European honeybee populations. The results may help to develop reliable microsatellite markers for more efficient preservation strategies of valuable honeybee breeds.