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        검색결과 1,207

        521.
        2013.10 구독 인증기관·개인회원 무료
        Sacbrood virus (SBV), a causative agent of larval death in honeybees, is one of the most devastating diseases in bee industry throughout the world. Lately the Korean Sacbrood virus (KSBV) induced great losses in Korean honeybee (Apis cerana) colonies. However, there is no culture system available for honeybee viruses, including SBV, therefore, the research on honeybee viruses is practically limited until present. In this study, we investigated the growth and replication of KSBV in cell cultures. The growth of KSBV was demonstrated by RT-PCR, quantitative real-time PCR, TEM and nucleotide sequence analysis. The results demonstrated that SBVshowed the replication signals in mammalian cell lines, including Vero cells without any signs of cytopathic effect (CPE). The results of RT-PCR, quantitative real-time PCR and in vivo infection with KSBV were also indicated the replication. Phylogenetic tree analysis shows our sequence included in distinct group with other SBV strains from China and Korea. It clearly showed the differenciation between field strain and attenuated strain through cell culture. The results of present study demonstrated for the first time that SBV like other animal viruses could be adapted and attenuated in cells through the sequential passages. The sequential adaptation through cell culture could result in discrepancy of pathogenicity of virus and morphological characterization. For this reason, the present results indicated that the cell adapted SBV could be a valuable tool to study the general properties of this emerging virus, including pathogenicity in the future.
        522.
        2013.10 구독 인증기관·개인회원 무료
        Caterpillars, the larvae of butters and moths(Lepidoptera), are enormously important in terrestrial food webs. They are not only the preferred grub for insects, birds, fishes, reptile and amphibian but also engineers of nutrient cycling processes and are the largest natural consumers of vegetation. Even though their major role in the ecosystem, details of biology are poorly known for most species. HECRI(Holoce Ecosystem Conservation Research Institution) has been carried out to identify larvae and to acquire useful biological information of primary endemic insect larvae through rearing from 1997 to 2013. Of these this study is the result about special caterpillars feeding on the foliage Oak Trees (Quercus spp.) which composed 60-70% of broad-leaved forest thereby important component for forest in the Korean Peninsula. Total 297 species belonging to 23 families were collected and identified 101 species belonging to 21 families. Among them Oak Trees-dependent monophagous caterpillars are 247 species belonging to 20 families and polyphagous caterpillars are 50 species belonging to 11 families. The dominant family is Noctuidae(83 species), second is Geometridae(67 species) and followed by Notodontidae(33 species).
        523.
        2013.10 구독 인증기관·개인회원 무료
        The Zena hawk moth(Langia zenzeroides) is one of the most dangerous insect pest feeding on Rosaceae fruits(Prunus persica Batsch, Prunus salicina Linnaeus) in Korea because of gregarious diet. The study was conducted to investigate biology and the temperature effect on adult emergence of overwintering L. zenzeroides pupae at five different constant temperatures (15, 20, 25, 27.5 and 30°C) with photoperiod 10:14(L:D) and relative humidity 60%. The lower developmental thresholds of L. zenzeroides were 9.7°C. Developmental period of overwintering pupae to adults decreased with increasing temperature from 15 to 30°C. Mortality of five different constant temperatures (15, 20, 25, 27.5 and 30°C) was 4, 8, 20, 8 and 48%. Especially mortality of constant temperature 30°C was higher than other conditions and survival rate of 15°C was the highest. Thermal constants of L. zeroenzides were 109.5DD. The relationship between the developmental rate and temperature was fitted by linear and one nonlinear developmental rate models (Lactin 1). The development variation of overwintering pupae was described by the two-parameter Weibull distribution model. We investigated development period in the study site by using 70 eggs. From egg to pupa period was 84.9±0.4.
        524.
        2013.10 구독 인증기관·개인회원 무료
        Temperature is one of important factors to determine insect phenology. Based on the bioclimatic law, the relationship between climate change and ecosystem change was studied from 2008 to 2013 in HECRI by monitoring the spring emergence patterns of three Papilionidae species (Papilio xuthus, P. machaon, and Sericinus montela). The overwintering pupae were set on the wood plate and adult emergence were monitored and recorded in every morning. The first spring emergence of P. xuthus, P. machaon and S. montela in 2013 were Apr 19th, May 1st and Apr 22th, respectively. And peak time of three species were May 7th, May 11th and May 9th, respectively. Study on temperature-dependent development was conducted to investigate the temperature effect on adult emergence of overwintering S. montela pupae at four different constant temperatures (15, 20, 25 and 30°C) with photoperiod 10:14(L:D). The low temperature threshold of female, male and both sexes combined were 12.39, 12.16, and 12.37°C, respectively. Developmental period of overwintering pupae to adults decreased with increasing temperature from 15 to 30°C. Thermal constant of female, male and both sexes combined were 220.26, 192.31, and 200.18DD, respectively. The relationship between thermal constant and cumulative adult emergence was predicted by temperature-dependent development. Estimate through 7 times on the highest temperature was equal and results were distinctively divided into two pattern(2008~2010 and 2011~2013). The relationship between observed and estimated values was presented by linear regression (r2=0.97)
        525.
        2013.09 구독 인증기관 무료, 개인회원 유료
        In the livestock feed industry, antibiotics are used to prevent disease, promote growth rate, and improve feed efficiency. However, antibiotic supplementation to animal feed results in increased bacterial resistance to antibiotics as well as antibiotic residues in animal products, which can negatively affect human health. Therefore, alternative sources of antibiotics are need- ed. Probiotics as an alternative to antibiotics in animal feed have been shown to increase feed efficiency and growth rate by improving microbial balance. Further, Bacillus sp. produces a wide spectrum of antibacte- rial peptides. The present study was conducted to investigate the effects of dietary supplementation with CS-32 on safety, growth rate, and feed efficiency. Antibacterial substance (5697.9 molecular weights) produced by CS-32 was isolated and purified from culture broth. Moreover, the results of minimal inhibi- tory concentration (MIC) test confirmed the excellent antibacterial effect of CS-32. In vivo, 0.1% and 1% CS-32 were fed to broiler chickens for 28 days. Feed efficiency was slightly higher in groups of chickens supplemented with 0.1% and 1% CS-32 than those of the control group. CS-32 had no significant effect on necropsy findings, hematology, or serum biochemistry, and there was no mortality. These results suggest that CS-32 among various biologically active substances may be safe and effective as a feed additive to improve growth rate and feed efficiency.
        4,000원
        526.
        2013.09 구독 인증기관 무료, 개인회원 유료
        Rutin is one of the major flavonoids found in buckwheat (Fagopyrum esculentum Moench). While rutin is already known to exhibit anti-oxidative, anti-inflammatory, and anti-carcinogenic activities. However, the health beneficial function of rutin metabolites is not well understood. In DPPH radical scavenging assays, the present study found that 3,4-dihydroxyphenyl acetic acid had the highest total anti-oxidant activity, followed by 3,4-dihydroxyphenylacetic acid, rutin, homovanillic acid, and 3-hydroxyphenyl acetic acid. Further, 3,4-dihydroxyphenylacetic acid strongly reduced LPS-induced IL-6 production in RAW 264.7 cells, compared with other metabolites. Therefore, these results suggest that rutin metabolites have potential to be utilized as food ingredients with anti-oxidant and anti-inflammatory activities.
        4,000원
        527.
        2013.08 구독 인증기관 무료, 개인회원 유료
        This is a miracle in movies. It’s the best shaman ritual with tears and blood through the camera. It’s Muel O’s talent to make it embracing the ordinary life not with the formalism of intellects. ‘Jiseul’ is one of the best movies this year and full of the immortal spirit. This is the review on the outcome from the minimal condition. You can imagine the outcome from more fulflling conditions. It’s time that we should fully support him who is dreaming to fly high where nobody has paid attention
        4,000원
        528.
        2013.06 구독 인증기관 무료, 개인회원 유료
        The current study was conducted in order to investigate bone formation using matrigel and angiogenic factors with HA and poly ε-caprolactone (HA/PCL) in a rat calvarial defect model. Calvarial defect formation was surgically created in Sprague Dawley rats (n=36). Rats in the control group (CD group, n=6) did not receive a graft. The HA/ PCL scaffold was grafted with matrigel (M-HA/PCL group, n=6) or without matrigel (HA/PCL group, n=6); and 100 ng of vascular endothelial growth factor with HA/ PCL scaffold containing matrigel (VEGF100 group, n=6), 100 ng (PDGF100 group, n=6) and 300 ng (PDGF300 group, n=6) of PDGF with HA/PCL scaffold containing matrigel were grafted in calvarial defects, respectively. Four weeks after surgery, bone formation was evaluated with micro computed tomography (micro CT) scanning, and histologically. According to the results, bone mineral density was significantly increased in the VEGF100, PDGF100, and PDGF300 groups compared to the HA/PCL group, in which angiogenic factors were not applied. In histological evaluation, more new bone formation around scaffolds was observed in the PDGF100 and the PDGF300 groups, compared with the VEGF100 group. Thus, the results indicate that HA/PCL containing matrigel with VEGF and PDGF is an effective grafting material for enhancement of bone formation in critical-sized bone defects. Especially, due to its price and capacity for bone formation, PDGF may be more effective than VEGF.
        4,000원
        529.
        2013.06 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to determine free radical scavenging capacity and oxidative DNA damage protecting activity of methanol extract of red tea stem. The extract was subjected to assess their antioxidant potential using various in vitro systems such as DPPH•, ABTS•+ , super oxide and nitric oxide free radicals and it exhibited IC50 values of 68.88 ± 1.1, 12.08 ± 0.65, 404.38 ± 1.6, 93.6 ± 2.7, µg/mL respectively. Red tea extract also showed ferric reducing ability (FRAP) with 2606.85 mmol Fe (II)/g of extract. Furthermore, Methanol extract of red tea stem showed significant DNA damage protecting activity in concentration dependent manner against H2O2+UV induced photolysis on pUC19 plasmid DNA. Results of this study showed that the methanol extract of Red Tea stem has strong antioxidant potential along oxidative DNA damage protecting capacity that would be the significant sources of natural antioxidants, which might be helpful in preventing the progress of various oxidative stress generated diseases. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidant.
        4,000원
        530.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The recent development in genetic assisted selection (combining traditional- and genome assisted selection method) and reproduction technologies will allow multiplying elite cow in Hanwoo small farm. This review describes the new context and corresponding needs for genome assisted selection schemes and how reproductive technologies can be incorporated to get more genetic gain for cow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree information are being generated from commercial farm sector and these are allowing to do genetic evaluation using BLUP to get elite cows in Korea. Moreover cattle genome information can now be incorporated into breeding program. In this context, this review will discuss about combining the reproductive techniques (Multiple Ovulation Embryo Transfer; MOET) and genome assisted selection method to get more genetic gain in Hanwoo breeding program. Finally, how these technologies can be used for multiplication of elite cow in small farm was discussed.
        4,000원
        531.
        2013.06 구독 인증기관 무료, 개인회원 유료
        Uncovering enzyme (UCE), encoded by the human NAGPA, is a trans-Golgi enzyme that adds the mannose-6- phosphate recognition tag on lysosomal enzymes destined for the lysosome. Mutations in NAGPA are known to cause stuttering, a common speech disorder with unknown etiology. The human NAGPA gene is transcribed into two different forms, probably due to alternative splicing. One of them, known as a brain isoform, is lacking exon 8 (102-bp). We performed quantitative real-time PCR for the NAGPA brain and non-brain isoforms in a cDNA panel originating from 16 human tissues and 24 sub-brain regions. According to our findings, the relative quantity of the NAGPA brain isoform in the brain was 4.7 times more than that in the control cDNA, a pooled mixture of equal amounts of cDNAs from the 16 different tissues. Further analysis using the cDNA panel originating from 24 different sub-brain regions revealed that the cerebral cortex contained the largest amount of NAGPA brain isoform. Relative quantity in the cerebral cortex was 8.6 times more than that in the control cDNA (P=0.00004). The lowest quantity of this isoform was detected in cDNA from the pituitary gland. In conclusion, findings of the current study suggest that the cerebral cortex, expressing the highest quantity of the NAGPA brain isoform, might be the region associated with speech function.
        4,000원
        532.
        2013.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study was an attempt to investigate whether the Task-Based Instruction (TBI) can fulfill its promises by looking into how a group of EFL college learners would perform in a TBI course. The research findings based on the analyses of the participants'performance on the proficiency tests of speaking and writing, the writing samples produced by the weekly journal task, and their responses to a questionnaire showed that the TBI course was effective enough to assist the learners to significantly improve proficiency levels of the L2 during such a time period of a 15-week long semester. The study also revealed that whether the learners would find the task topic interesting was significantly related to their confidence in using the L2, evaluation on the instructor's way of teaching, and overall evaluation on the TBI course. It also found that the college-level learners did not favor grammar instruction provided in an explicit way while appreciating opportunities to use the L2 in productive modes.
        6,300원
        533.
        2013.05 구독 인증기관 무료, 개인회원 유료
        Smart phones have drastically changed the life of today’s competitive world. Smart phone application (App) developers are trying their best to meet the customer requirements in the most efficient way while considering all its attributes. However smart phone service quality has been given less consideration comparatively during the last few years. This paper proposes a measurement method for improving service quality of smart phone application. This method combines the service quality performance model and process capability index. The service quality performance model is used to identify service items that require improvement. Process capability index is used to prioritize these items for improvement. We collected data on satisfaction level of customers who have used application service. By the proposed method, we found five significant service items from three categories - execution, security and resilience and prioritized those items for improvement.
        4,000원
        534.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Microtubule-associated protein 1B (MAP1B), a member of MAP1 family, plays a key role in neuronal development. MAP1B binds to many kinds of proteins directly or indirectly. This study was performed to investigate whether MAP1B interacts with GAPDH in bovine follicles using immunoprecipitation (IP) with Western blot analysis and immunohistochemisty. The mRNA expressions of MAP1B and glyceraldehydes 3-phosphate dehydrogenase (GAPDH) were down-regulated in bovine follicular cystic follicles (FCF). In parallel with the mRNA levels, their protein levels were also down-regulated in FCFs. In addition, MAP1B and GAPDH were co-localized at the cytoplasm of follicles. IP with Western blot analysis showed that MAP1B bound to GAPDH in normal follicles, but their binding was absent in FCFs, suggesting a low level of MAP1B and/or GAPDH expressions in FCFs. Taken together, these results suggest that MAP1B interacted with GAPDH may play a role in bovine follicle development, and that GAPDH does not function always as a loading control in bovine follicles.
        4,000원
        535.
        2013.03 구독 인증기관 무료, 개인회원 유료
        The objective of this experiment was to assess the relationship between electrical resistance of the vaginal mucosa and plasma progesterone for optimal mating time in the bitch. Eight mature beagle bitches were examined, and we observed eight times of estrus. Vaginal electric resistance was recorded weekly using a Draminski ovulation detector in anestrus, and daily in estrus. Plasma progesterone concentration was estimated by radioimmunoassay. In the bitch, incline in vaginal electric resistance (376.20 ± 105.63 units) showed a closely association with the onset of proestrus. Ovulation day was determined as the first day when plasma progesterone concentration increased above 5.0 ng/ml (Day 0). On Day 0, vaginal mucous electric resistance was 438 ± 132 units. Vaginal mucous electric resistance showed a slight decrease or was maintained until Day 0. However, it showed an explosive increase, and peaked on Day 1~3, which was above 600 units. Two of eight cases peaked on Day 1, three of eight cases were revealed on Day 2, and others were revealed on Day 3. After Day 4, resistance showed a rapid drop to below 600 units and reached 200 units on Day 8. The optimal mating time was determined when vaginal mucous electric resistance was above 600 units.
        4,000원
        536.
        2013.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nonthermal radiation from supernova remnants (SNRs) provides observational evidence and constraints on the diffusive shock acceleration (DSA) hypothesis for the origins of Galactic cosmic rays (CRs). Recently it has been recognized that a variety of plasma wave-particle interactions operate at astrophysical shocks and the detailed outcomes of DSA are governed by their complex and nonlinear interrelationships. Here we calculate the energy spectra of CR protons and electrons accelerated at Type Ia SNRs, using time-dependent, DSA simulations with phenomenological models for magnetic field amplification due to CR streaming instabilities, Alfv´enic drift, and free escape boundary. We show that, if scattering centers drift with the Alfv´en speed in the amplified magnetic fields, the CR energy spectrum is steepened and the acceleration efficiency is significantly reduced at strong CR modified SNR shocks. Even with fast Afv´enic drift, DSA can still be efficient enough to develop a substantial shock precursor due to CR pressure feedback and convert about 20-30% of the SN explosion energy into CRs. Since the high energy end of the CR proton spectrum is composed of the particles that are injected in the early stages, in order to predict nonthermal emissions, especially in X-ray and -ray bands, it is important to follow the time dependent evolution of the shock dynamics, CR injection process, magnetic field amplification, and particle escape. Thus it is crucial to understand the details of these plasma interactions associated with collisionless shocks in successful modeling of nonlinear DSA.
        4,800원
        537.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was carried out to determine the effect of different spectrum conversion greenhouse films (red, blue, red+blue) to changing microclimate and subsequent effect on growth and quality of lettuce (Lactuca sativa L.), tomato (Solanum lycopersicum L.), and melon (Cucumis melo L.) Transmission of PAR (photosynthetic active radiation, 400-700 nm) under red, blue, and blue+red (BR) films was higher by 7.2, 7.6, and 5.8%, respectively, as compared with control greenhouse film. Light transmission in the 300-1100 nm wave band was 91.6% and 91.3% under red and blue films, respectively, compared to 86.4% under control film. Mean daytime temperature in greenhouse was slightly higher in red and blue film and mean night time temperature was higher in BR film. There were no significant differences in relative humidity among the films. Number of leaves and plant fresh weight of lettuce were higher under BR film. Total number of marketable tomato fruits was greater under blue and BR film and fruit weight was heavier under red and blue film compared to control film. Under BR and red film melon fruit weight was increased by 140 g and 80 g respectively, as compared to control film. Sugar content in melon and tomato fruits was not affected by covering films.
        4,000원
        538.
        2012.12 구독 인증기관 무료, 개인회원 유료
        To clarify the role of stem cells in hepatocarcinogenesis, octamer-binding transcription factor 4 (Oct4) expression was investigated in mouse liver and embryonic cell lineages. In vivo, at 14 days of age, ten ICR mice were divided into two groups and treated with saline or diethylnitrosamine (DEN), and were sacrificed at 6 h after treatment. Livers were fixed in 10% neutral phosphate buffered formalin, embedded in paraffin, sectioned to a thickness of 5 μm, and immunohistochemical analysis of Oct4 was performed. In vitro, mouse embryonic stem cells, hepatic progenitor cells and hepatocytes, representing 0, 22, and 40 days of differentiation, respectively, were treated with DEN at four doses (0, 1, 5 and 15 mM; G1, G2, G3 and G4, respectively) for 24 h and RNA was isolated; Oct4 and Gadd45a mRNA were investigated. In vivo, Oct4 expression was not detected in saline-treated livers. However, its expression was observed in hepatocytes of mice treated with DEN, showing cytoplasmic staining. In vitro, Oct4 expression differed significantly for G4 on day 0 (P<0.05) and for G2 on day 22 (P<0.01) and G3 and G4 on day 40 (P<0.05 and P<0.01, respectively) compared with G1 at each time point. Gadd45a expression differed significantly in G4 (P<0.01) on day 0 and G4 on day 40 (P<0.01), compared with that of G1 at each time point. Taken together, Oct4 expression was increased by treatment with DEN in hepatocytes, however, not in embroyonic stem cells and hepatic progenitor cells. This finding suggests that Oct4 expression may be modulated in hepatocarcinogenesis induced by DEN.
        4,000원
        539.
        2012.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        전해정련을 이용한 폐 피복관 처리의 타당성을 살펴보기 위하여, 500℃의 LiCl-KCl 용융염 내에서 표면이 산화된 10 g 규모의Zircaloy-4 피복관 및 순수한 Zircaloy-4 피복관의 전기화학적 거동을 살펴보았다. 산화된 Zircaloy-4 피복관이 담긴 basket을 작업전극으로하여 전압-전류 관계를 측정한 결과, 산화되지 않은 Zircaloy-4 피복관과 비교해 Zr의 산화 peak는 Ag/AgCl 기준전극 대비, 약 -0.7 V ~ -0.8 V로 유사한 반면, 산화 전류의 크기는 확연하게 감소하는 것으로 나타난다. 이러한 결과는 -0.78V의 일정전위를 가한 전기화학적 용해 실험에서 살펴본 전류-시간 곡선에서도 유사하게 나타나며, 피복관 조각들의 평균 두께 및 무게 변화로부터 확인할 수 있다. Zircaloy-4 피복관이 산화되었을 경우, 표면의 산화막이 피복관의 전도성에 영향을 주어 basket 내 위치에 따라 전기화학적 용해의 균일성 및 속도를 떨어뜨리는 것으로 나타나지만, 표면의 미세한 결함과 Zr 산화물의 상 특성으로 인해 전기화학적 용해가 진행되는 것으로 판단된다.
        4,000원
        540.
        2012.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        4,300원