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        검색결과 409

        221.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        The mannanase, cellulase and xylanase-producing thermophilic bacteria, designated EJ3, was isolated from fresh spent mushroom (Pleurotus eryngii) substrates taken from the DOJUN farm located in Keyongnam, Korea. The isolate EJ3 was facultatively anaerobic and grew at temperature ranging from 20℃ to 60℃ with an optimal temperature of 37℃. The DNA G+C content of the isolate EJ3 was 45 mlo%. The major fatty acids were anteiso-15:0 (38.9%), 17:0 (7.4%), and iso-15:0 (38.2%). The 16S rRNA gene sequence similarity between the isolate EJ3 and other Bacillus strains varied from 97% to 99%. In the phylogenetic analysis based on these sequences, the isolate EJ3 and Bacillus subtilis clustered within a group and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate EJ3 was classified within the genus Bacillus as Bacillus subtilis EJ3. The optimal growth condition of B. subtilis EJ3 were pH 6.0 and 55℃, respectively.
        222.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the feeding value of the spent mushroom (Pleurotus eryngii) substrates (SMS) in laying hens (Hy-Line Brown). The fresh spent mushroom (Pleurotus eryngii) substrates collected from the DOJUN farm were fermented with Bacillus subtilis EJ3 for 2 weeks. A total of twenty-four laying hens were fed corn-soy based experimental diets containing 0% (control), 5% (T1), 10% (T2) and 15%(T3) fermented SMS for 7 weeks. There were no significant differences among the treatments in egg production, egg weight, egg mass, feed conversion and viability during the experimental period. Feed intake was significantly lowered in control (118.3 g) than T1 (121.9 g), T2 (120.3 g) and T3 (122.4 g). There were no significant differences among the treatments eggshell breaking strength, thickness and haugh unit, whereas the yolk color of T1, T2 and T3 were significantly heavy than T0. The palatability of boiled meat was significantly better in the T3 laying hens than in the T0 laying hens. In conclusion, fermented SMS can be used as resource of feed in laying hen feed at 5.0-15% level without effect on performance and egg qualify.
        227.
        2010.10 구독 인증기관·개인회원 무료
        The first commercial bioinsecticide in Korea was registered in 2003 to control diamond back moth and beet armyworm in Chinese cabbage using Bacillus thuringiensis subsp. aizawai. Currently, fourteen microbial pesticides have registered in Korean market. The Korean government is aiming for 40% reduction (from the 2004 value) in the use of chemical pesticides by 2013. To increase the use of microbial pesticides as an alternative of chemicals, we conducted in vitro bioassay with Bt products. Bt products were treated alone and in combination against larvae of beet armyworm, diamond back moth and tobacco cutworm. Five Bt products shown high mortality against diamond back moth in recommended concentration, but had low control effects against beet armyworm and tobacco cutworm. Mixed Bt products had no synergic effects against the tested three moths. When Bt products were sprayed with higher concentration than recommended dose, those mortality was similar with lower concentration.
        228.
        2010.10 구독 인증기관·개인회원 무료
        The black soldier fly (Hermetia illucens) (Diptera: Stratiomyidae) is an invasive species that is thought to be endemic in Korea. The insect has been paid much attention thanks to its ability to decompose organic wastes. We collected the insect nation-wide in 2006 and 2010 to investigate its genetic structure based on the mitochondrial cytochrome oxidase 1 (mt CO1) haplotype. The results show that during the time period the insect seems to lose some rare haplotypes. We conclude that the insect may have experienced genetic bottleneck while its settlement in Korea. In our presentation, we show its updated haplotype network and genetic differentiation and propose potential explanations.
        229.
        2010.10 구독 인증기관·개인회원 무료
        Scirtothrips dorsalis Hood is a newly advent pest on citrus in Jeju. Both larvae and adult attack the new shoots and young and matured fruits of citrus. S. dorsalis is highly polyphagous with over 100 recorded species, but not known in Jeju. As a result from investigating the host plants in and/or around citrus orchards in Jeju during 2009 to 2010, they were 25 families 39 species. The total thrips examined on those plants were 13 species, and the richness thrips among them was S. dorsalis, Frankliniella occidentalis, Thrips tabaci and Thrips hawaiiensis. The widespread host plants of S. dorsalis were Mallotus japonicus, Paederia scandens, Hedera rhombea, Cayratia japonica and Clematis apiifolia and they can be also used for monitoring plants. On early May, the larvae of S. dorsalis were first investigated on the shoots of Mallotus japonicus, Lonicera japonica, Paederia scandens, Viburnum awabukira, Fraxinus rhynchophylla and Celtis sinensis. The other thrips species except S. dorsalis and T. tabaci, especially F. intonsa, T. hawaiiensis, T. flavus and T. coloratus were just found on flower stalks during the blooming season.
        230.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to develop a novel qualitative multiplex polymerase chain reaction (PCR) for simultaneous detection of genetically modified (GM) soy and maize within a single reaction. The specific primers designed to detect four respective GM events (A2704-12, MON88017, Bt11, and MON863) were included in the tetraplex PCR system. Each of PCR products for four GM events could be distinguished by agarose gel based on their different lengths. The specificity and reproducibility of this multiplex PCR were evaluated. This multiplex PCR consistently amplified only a fragment corresponding to a specific inserted gene in each of the four GM events and also amplified all four of the PCR products in the simulated GM mixture. These results indicate that this multiplex PCR method could be an effective qualitative detection method for screening GM soy and maize in a single reaction.
        3,000원
        231.
        2010.05 구독 인증기관·개인회원 무료
        The males of cryptic mealybug, Pseudococcus cryptus, were attracted on trap baited with or without a synthetic sex pheromone. The attractiveness of sex pheromone trap was higher than yellow-color sticky trap, but both phenologies were similar. There was a positive relationship between mean density of 2nd nymph to adult cryptic mealybug and the density of the male caught on trap. The density of cryptic mealybug per tree was higher correlated with yellow-color sticky trap than sex pheromone trap. The pattern of cryptic mealybug male occurrence had two to three cohorts in a generation resulted from overwintering stage. The maximum occurring time of 1st to 2nd nymph stage could be estimated from the peak time of trap catch by effective temperature accumulation. The higher and lower threshold temperature was estimated as 10.9 and 32.6℃, respectively and its thermal constant was 360 degree-day. The cryptic mealybug parasitoid, Anagyrus sp., which was first recovered in Jeju in 2009, was well attracted on yellow-color sticky trap. There was a high correlation between the density of Anagyrus sp. and of cryptic mealybug males caught on trap.
        232.
        2010.05 구독 인증기관·개인회원 무료
        This study was conducted to investigate the insecticidal capacity of several recombinant baculoviruses to P. xylostella and S. exigua larvae. NeuroBactrus was constructed as follows: the cry1-5 of Bacillus thuringiensis 2385-1 was inserted into Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of polyhedrin gene promoter, and insect-specific neurotoxin from the scorpion Androctonus australis (AaIT) under the control of early promoter from Cotesia plutellae bracovirus was introduced by fusion of orf603 partial fragment in the opposite direction of polyhedrin gene, respectively. Other recombinant baculoviruses derived from the NeuroBactrus - NBt-DelA (deleted AaIT), NBt-Del5 (deleted cry1-5), and NBt-DelA5 (deleted AaIT and cry 1-5) - were manufactured in serial passages in vitro. The data were analyzed by SPSS. The value of LC50 was lower when P. xylostella larvae fed on cabbage coated with NeuroBactrus (4068.4) than when it fed on cabbage coated with AcMNPV (4.5x106). Survival time (ST50) of P. xylostella larvae (2.54days) was shorter when it fed on cabbage coated with NeuroBactrus than when it fed on cabbage coated with other recombinant baculoviruses (7.54days, 7.68days, and 8.26days) and AcMNPV (9.67days). S. exigua larvae presented the same results.
        233.
        2009.10 구독 인증기관·개인회원 무료
        The damage of citrus fruit by yellow tea thrips, Scirtothrips dorsalis Hood, was first confirmed in 2008, and has since been one of the serious pests of citrus in Jeju. This was reported on damage symptom on tangor cultivar, Setoka (Tangor Norin No. 8) fruits cultivated in a greenhouse and the characteristic of spatial disttribution of S. dorsalis caught on yellow sticky traps was conducted in three commercial citrus orchards. The feeding habits by S. dorsalis cause rind blemishes on the navel part of fruit. The damage is characterized by being scarped and figure like covered cloud on satsum mandarine fruit, but on by a brown ring of rough russeting that occurs on navel part of Setoka fruit. The season of damage occurrence was from middle of June to late of July. There was a highly significant relationship between the average number of thrips per trap and the maximum number caught on a trap. The overall differences between the linear regression models obtained from mean-variance relationship for each surveyed fields were tested by type Ⅲ error and contrast method. The characteristic of spatial distribution of S. dorsalis was better described by Taylor's power law than Iwao's patchiness regression, and the dispersion index which is the slope (=1.72) of linear regression model showed the aggregated distribution pattern. The sequential sampling stop lines at fixed precision level of 0.20, 0.25 and 0.30 were calculated.
        235.
        2009.05 구독 인증기관·개인회원 무료
        Some responses of cryptic mealybug, Pseudococcus cryptus, for a sex pheromone, [(1R,3R)-3-isopropenyl-2,2-dimethylcyclobutyl]methyl 3-methyl-3-butenoate, were studied to develop the applying strategy of sex pheromone trap for efficient monitoring and control-time decision in citrus orchards grown in greenhouse for 2 years (2007-2008). The optimal concentration of a sex pheromone was 1.0㎎ per hexane 100㎕ in a using pheromone lure. There was no significant effect of the attraction of male adults among different colours (white, blue and yellow) of plate-type trap baited with sex pheromone. The more male adults were attracted, as the distance of a pheromone trap form a citrus tree infested with cryptic mealybug was closer. The male adults were caught to sex pheromone trap from middle April to late November, and its peak period was the middle of July. The thermal constant for the next attraction was about 640 degree-days (lower threshold temperature=12℃) after confirmed the first attraction of male adults. The optimum control time for cryptic mealybug after the first attraction of male adults were confirmed was estimated as 450 to 500 degree-days.
        237.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Bicuculline is one of the most commonly used GABAд eceptor antagonists in electrophysiological research. Because of its poor water solubility, bicuculline quaternary ammonium salts such as bicuculline methiodide (BMI) and bicuculline methbromide are preferred. However, a number of studies have shown that BMI has non-GABAд eceptor-mediated effects. The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is implicated in the processing of nociceptive signaling. In this study, we investigated whether BMI has non-GABA receptor-mediated activity in Vc SG neurons using a whole cell patch clamp technique. SG neurons were depolarized by application of BMI (20M) using a high Cℓ⁻ipette solution. GABA ( 30-100μM) also induced membrane depolarization of SG neuron. Although BMI is known to be a GABAд receptor antagonist, GABA-induced membrane depolarization was enhanced by co-application with BMI. However, free base bicuculline (fBIC) and picrotoxin (PTX), a GABAд and GABAс receptor antagonist, blocked the GABA-induced response. Furthermore, BMI-induced membrane depolarization persisted in the presence of PTX or an antagonist cocktail consisting of tetrodotoxin (Nα+ nnel blocker),AP-5 (NMDA receptor antagonist), CNQX (non-NMDA receptor antagonist), and strychnine (glycine receptor antagonist). Thus BMI induces membrane depolarization by directly acting on postsynaptic Vc SG neurons in a manner which is independent of GABAд receptors. These results suggest that other unknown mechanisms may be involved in BMI-induced membrane depolarization.
        4,000원
        238.
        2008.10 구독 인증기관·개인회원 무료
        The porcine reproductive and respiratory syndrome virus (PRRSV) has six structural proteins which encoded by ORFs 2 to 7 are designated as GP2, 3, 4, 5, M and N, repectively. In this study, we determined the expression of each protein using novel transfer vector, pBmKSK4 which has the polyhedrin promoter of BmNPV and 6xHis tag. The recombinant transfer vector was co-transfected into Bm5 cells along with bBpGOZA DNA. Recombinant virus was purified by plaque assay and amplified in Bm5 cells. Expression of each protein was identified by SDS-PAGE and Western blot analysis using anti-6xHis monoclonal antibody. The expression levels of the structural proteins in Bm5 cells were stronger than the expression system using pBacPAK9 transfer vector in Sf21 cells. As expected, GP5 was expressed at low levels from its structural properties and its toxicity for cells. In addition, each recombinant protein was purified using Ni-NTA spin columns. The ability to produce each protein in the baculovirus system indicates that these could be major candidates for the development of a vaccine against PRRSV.
        239.
        2008.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        As a continuation of a previous work by Park et al. (2006), we have developed a two-element radio interferometer that can measure both the phase and amplitude of a visibility function. Two small radio telescopes with diameters of 2.3 m are used as before, but this time an external reference oscillator is shared by the two telescopes so that the local oscillator frequencies are identical. We do not use a hardware correlator; instead we record signals from the two telescopes onto a PC and then perform software correlation. Complex visibilities are obtained toward the sun at λ=21cm for 24 baselines with the use of the earth rotation and positional changes of one element, where the maximum baseline length projected onto UV plane is ~90λ As expected, the visibility amplitude decreases with the baseline length, while the phase is almost constant. The image obtained by the Fourier transformation of the visibility function nicely delineates the sun, which is barely resolved due to the limited baseline length. The experiment demonstrates that this system can be used as a "toy" interferometer at least for the education of (under)graduate students.
        4,000원