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        검색결과 1,242

        621.
        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.
        622.
        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.
        623.
        2013.10 구독 인증기관·개인회원 무료
        A taxonomic review on the Korean Lymantria Hübner, 1819 was conducted. In a result, a total of nine species under four subgenera including two new recorded species were detected as followings: L. dispar asiatica Vnukovskij, 1926, L. xylina Swinhoe, 1903, L. monacha (Linnaeus, 1758), L. minomonis Matsumura, 1933, L. sugii Kishida, 1986, L. lucescens (Butler, 1881), L. mathura Moore, 1865, L. fumida Butler, 1877, and L. bantaizana Matsumura, 1933. Of the two unrecorded species, L. minomonis was found only in Is. Bogildo of Jeollanam-do, the southern part of Korea, and the other one, L. sugii was collected in the middle part of Korea. On the two species, L. xylina and L. fumida, the Korean specimens could not be examined through this study. Therefore, we considered that the two species might be excluded from the Korean Lymantria fauna. Each species was identified on the basis of wing pattern and genitalia of male/female adult. We provided diagnosis, male/female adult habitus photos, male genitalia photos, and female ovipositor photos.
        624.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369- 3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress (42°C) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.
        4,000원
        625.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Graphene is a fascinating material with excellent electrical, optical, mechanical, and chemical properties. Remarkable progress has been made in the development of methods for synthesizing large-area, high-quality graphene. Recently, the chemical vapor deposition method has opened up the possibility of using graphene for electronic devices and other applications. This review covers simple and inexpensive methods to grow graphene using polymers as solid carbon sources; which do not require an additional process to transfer graphene from the growth substrate to the receiver substrate.
        4,000원
        626.
        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
        627.
        2013.09 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to compare the effects of the levels of inbreeding on body weight traits between two breed populations, Hanwoo and Korea Brindle cattle. Birth weight (BW), weaning weight (WW), body weight at 6 months of age (W6) and yearling weight (YW). Records of 1,745 calves (1,513 from Hanwoo, and 232 from Korea Brindle calves) were collected from Livestock Research Institutes in Kangwon, Gyeongbuk and Chungbuk provinces. The least squares means (LSM) and their standard errors for BW, WW, W6 and YW were 25.4±0.1 kg, 81.0±1.8 kg, 146.1±3.7 kg and 291.5±2.4 kg, respectively in Hanwoo calves and 22.6±0.3 kg, 79.9±2.3 kg, 137.6±4.6 kg and 249.3±6.6 kg, respectively in Korea Brindle calves. Pedigree data showed that 14.8% (316 out of 2131) of Hanwoo was inbred and the average inbreeding coefficient was 0.0209 (2.09%). Inbreeding coefficients of ten calves out of 316 total inbred Hanwoo calves were 12.5% or higher, whereas those of the other 306 calves were less than 12.5%. In both breeds, calves were divided into three groups of inbreeding classes - highly inbred group(F≥ 0.125), lowly to medially inbred group(0<F<0.125) and no inbred group(F=0). In Korea Brindle calf populations, 12.2% of the calves observed (57 out of 467 calves) were inbred and the average inbreeding coefficient was 0.1367(13.67%). Forty four calves out of 57 inbred Korea Brindle calves had inbreeding coefficients of 12.5% or higher and the other 13 calves had less than 12.5% of inbreeding coefficients. Average inbreeding coefficient and the number of calves with greater than 12.5% inbreeding coefficient were higher in Korea Brindle calf groups than in Hanwoo calf groups. On the average, body weight growth of Korea Brindle calves was slower than that of Hanwoo calves. This would be due to very small breeding population structure of Korea Brindle cattle as compared to Hanwoo cattle, which would lead to rapid increase in inbreeding coefficients in the population. In conclusion, our study suggests that planned mating system is needed to control inbreeding in Korea Brindle population.
        4,000원
        628.
        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
        631.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to examine the effect of in vitro maturation (IVM) medium, cytochalasin B (CB) treatment during intracytoplasmic sperm injection (ICSI), and electric activation on in vitro development ICSI-derived embryos in pigs. Immature pig oocytes were matured in vitro in medium 199 (M199) or porcine zygote medium (PZM)-3 that were supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then further cultured in hormone-free medium for an additional 21~22 h. ICSI embryos were produced by injecting single sperm directly into the cytoplasm of IVM oocytes. The oocytes matured in PZM-3 with 61.6 mM NaCl (low-NaCl PZM-3) tended to decrease (0.05<P<0.1) nuclear maturation when compared with oocytes matured in M199 (76.9% vs. 83.8%) but no significant differences were found in embryo cleavage, blastocyst formation, and mean number of cells in blastocyst (73.8% vs. 74.6%, 11.1% vs. 12.1%, and 28.4 cells vs. 30.1 cells, respectively). The oocyte degeneration was not reduced by CB treatment during ICSI (11.9%) when compared with no treatment control (11.3%) while the treatment showed detrimental effects (P<0.05) on embryonic cleavage (40.0%) and blastocyst formation (1.8%) rates when compared with control (60.0% and 11.5%, respectively). For activation of ICSI oocytes, additional electric stimulus has no positive or negative effect on in vitro development of preimplantation stage ICSI porcine embryos. Our results demonstrate that CB treatment during ICSI inhibits embryonic development of ICSI oocytes and additional electric activation after ICSI has no effect in improving ICSI embryonic development in pigs. Further studies are needed to improve ICSI efficiency by investigating factors influencing embryonic development after ICSI in pigs.
        4,000원
        632.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Size-sorted graphene nanoplatelets are highly desired for fundamental research and technological applications of graphene. Here we show a facile approach for fabricating size-sorted graphene oxide (GO) nanoplatelets by a simple centrifugal method using different dispersion solvents. We found that the small-sized GO nanoplatelets were more effectively separated when dispersed in water or dimethylformamide (DMF) than in an alkali aqueous solution. After several iterations of the centrifugation, the sizes of GO in the supernatant solution were mostly several micrometers. We found that the GO area was not strongly correlated with the C-O content of the GO dispersed in water. However, the size-sorted GO nanoplatelets in DMF showed different C-O content, since DMF can reduce GO nanoplatelets during exfoliation and centrifugation processes.
        4,000원
        633.
        2013.06 구독 인증기관 무료, 개인회원 유료
        Matrix metalloproteinases (MMPs) have been known to affect to cell migration, proliferation, morphogenesis and apoptosis by degrading the extracellular matrix. In the previous studies, undifferentiated mouse embryonic stem cells (ESCs) were successfully proliferated inside the extracellular matrix (ECM) analog-conjugated three-dimensional (3D) poly ethylene glycol (PEG)-based hydrogel. However, there is no report about MMP secretion in ESCs, which makes it difficult to understand and explain how ESCs enlarge space and proliferate inside 3D PEG-based hydrogel constructed by crosslinkers containing MMP-specific cleavage peptide sequence. Therefore, we investigated what types of MMPs are released from undifferentiated ESCs and how extracellular signals derived from various niche conditions affect MMP expression of ESCs at the transcriptional level. Results showed that undifferentiated ESCs expressed specifically MMP2 and MMP3 mRNAs. Transcriptional up-regulation of MMP2 was caused by the 3D scaffold, and activation of integrin inside the 3D scaffold upregulated MMP2 mRNAs synergistically. Moreover, mouse embryonic fibroblasts (MEFs) on 2D matrix and 3D scaffold induced upregulation of MMP3 mRNAs, and activation of integrins through conjugation of extracellular matrix (ECM) analogs with 3D scaffold upregulated MMP3 mRNAs synergistically. These results suggest that successful proliferation of ESCs inside the 3D PEG-based hydrogel may be caused by increase of MMP2 and MMP3 expression resulting from 3D scaffold itself as well as activation of integrins inside the 3D PEG-based scaffold.
        4,000원
        635.
        2013.04 구독 인증기관 무료, 개인회원 유료
        In the field of study about the maritime safety system various reports have been given on the research of ship auto control over a long time but lack of auto control designed for auto berthing control. This paper deals with ship"s track keeping control on
        3,000원
        636.
        2013.04 구독 인증기관·개인회원 무료
        This study selected 10 species commonly emerging in Busan and Daegu showing distinct green structure distributions, and distribution differences were mapped and analyzed according to city of origin. As for G-IS (Green-Inhabiting Species) of both cities, there were six species, including V. mandarinia, V. ducalis, V. crabro flavofasciata, Vl. koreensis koreensis, Pa. indica, and P. snelleni, which mostly inhabited urban source green and satellite green structures. As for GU-IS (Green & Urban-Inhabiting Species), there were two species, V. simillima simillima and V. analis parallela, which nested at diverse sites and showed greater preference for green structures. On the other hand, U-IPS (Urban-Inhabiting Preference Species) consisted of two species, V. velutina nigrithorax and P. rothneyi koreanus, which nested at almost all sites, including urban and urban green areas, and were found to adapt well to an urban environment based on their far higher rate of urban nesting as compared to GU-IS species. In comparing emergence rates among the four urban GU-IS and U-IPS species in Busan and Daegu, regular distribution was mostly observed within the city of Busan, which is well equipped with a green network, whereas Daegu, which lacks green structure connectivity, showed its greatest distribution of species nearby urban green areas. Also this study shows that in Daegu with longer distance between green, U-IPS emerged up to far site beyond green areas as compared to Busan, which has short distances between green areas.
        637.
        2013.04 구독 인증기관·개인회원 무료
        The body and head lice (Pediculus humanus humanus and Pediculus humanus capitis, respectively) are hematophagous ectoparasites of humans and only the body louse between two is known to transmit three bacterial diseases through its feces. The proliferation profiles of Bartonella quintana, the causative agent of trench fever, inside the louse body and its excretion patterns were investigated in the two louse subspecies following oral challenge with B. quintana-infected blood meal. The initial density of B. quintana was sustained inside head lice without any noticeable proliferation for the entire period after infection. In contrast, B. quintana proliferated rapidly inside body lice and the maximum density reached at 10 days post-infection. The numbers of bacteria detected in feces from infected lice were almost the same and steadily decreased over time in both body and head lice. Nevertheless, the viability of the bacteria, as determined by fluorescence, was significantly higher in body louse feces, especially at 1 day post-infection and this tendency lasted for 11 days. These findings suggest that excretion of feces containing more viable B. quintana that is proliferated inside body lice following ingestion of infected blood meal is responsible for the higher vector competence of body lice.
        638.
        2013.04 구독 인증기관·개인회원 무료
        In a faunistic survey for the family Coleophoridae (Lepidoptera: Gelechioidea) on Is. Yeonpyeong and Is. Baengnyeong in 2010 and 2006, respectively, eleven species of Coleophora were recognized. Among them, three species; Coleophora adjunctella Hodgkinson, C. chenopodii Oku, and C. kurokoi Oku are reported for the first time from Korea. For the newly recorded species, taxonomical remarks and illustration of adults and genitalia are given.
        639.
        2013.04 구독 인증기관·개인회원 무료
        In apple orchards under different farming practices (organic and conventional), arthropod community structure was investigated. Arthropods were collected with pitfall traps, band traps, yellow sticky traps and pheromone traps from May to December, 2012 in Danyang-gun, Chungcheongbuk-do, Korea. Biodiversity was analyzed with species richness and Shannon diversity index (H΄). Sampled arthropods were identified 37 families in 14 orders from 21,618 individuals in organic orchard-1 and 33 families in 10 orders from 11,318 individuals in organic orchard-2 and 35 families in 13 orders from 27,711 individuals in conventional orchard. Species richness was relatively highest in organic orchard-1, intermediate in conventional orchard and lowest in organic orchard-2. In ecologically functional group, abundance of pests was higher in conventional orchard than in organic orchards due to the high occurrence of Phyllonorycte ringoniella (Gracillariidae) and Lyonetia prunifoliella (Lyonetiidae). Organic orchards showed higher abundance, species richness and species diversity of epigeic predators and those of parasitoids above ground than conventional orchard. Abundance of detritivores, mainly collembola, were higher in organic orchard than in conventional orchard.
        640.
        2013.04 구독 인증기관·개인회원 무료
        We compared the grafting success in total of 107 rearing Apis carana queens cells, to which we grafted 540 larvae. The wax for cups we prepared from A. mellifera and A. cerana wax. The A. cerana wax cups were found that artificial queen cell cups with the internal diameter of 8.0 mm at the mouth and 8.0 mm depth were highly preferred by the bees for rearing of queens from the grafted larvae. From the 210 grafted larvae into A. mellifera wax bees accepted 30 queens cells, only (16.67 %) ; A. cerana wax bees accepted 59 queens cells (33 %) ; plastic cup bees accepted 18 queens cells, only (10 %). In the preference test the grafting success in the A. cerana wax cups were better than in the A. mellifera wax and plastic cup. The results show better acceptance of larvae grafted into the pure A. cerana wax cups for rearing A. cerana queen. A new method for rearing honey bees, A. cerana, in vivo was developed and the effects of royal jelly from A. mellifera. We used royal jelly diluted 50:50 with sterile water (The royal jelly is kept frozen until used). A small amount of royal jelly is placed at the center of each cell cup. Young A. cerana larvae were transferred into the queen cups containing ± 10 ㎍ of the Royal jelly from A. mellifera and A. cerana. The average rates of acceptance were affected significantly due to the royal jelly source in the queen cell cups. It is so workable first to produce pure A. cerana wax for making the queen cups before a beekeeper starts with grafting.