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        검색결과 1,238

        661.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Brucellosis is an important and re-emerging zoonotic disease worldwide. The prevention of human infection is achieved predominantly through the control of brucellosis in agricultural animals, which in turn depends on accurate diagnosis and vaccination. However, conventional serological diagnosis of brucellosis has several limitations, and currently available vaccines for animals have several drawbacks, including the ability to cause infection in humans. Phosphoglycerate kinase (Pgk) is one of the specific proteins reactive with mouse sera in the early stage of Brucella infection, and deletion of the pgk gene in B. abortus strain 2308 resulted in extreme attenuation of this strain in vitro and in vivo. Furthermore, the B. abortus pgk mutant has been used as a live vaccine, and in challenge experiments, it induced protection that was superior to that conferred by commercial strains. In this study, the pgk gene from Brucella abortus 544 was successfully amplified and cloned into a maltose binding protein fusion protein expression vector (pMAL). The recombinant protein was expressed in Escherichia coli DH5α and purified. The immunogenicity of purified recombinant B. abortus 544 Pgk (rPgk) was evaluated by western blot analysis using Brucella-positive mouse sera. rPgk could be used as an antigenic component for future serological tests and potential vaccine development.
        3,000원
        665.
        2014.10 구독 인증기관·개인회원 무료
        Entomopathogenic fungi infect some arthropod pest and have been used for biological control. Some entomopathogenic fungi have high potential in insect pest management worldwide, and most of researches were given to Hypocreales order of Ascomycota, but little in Zygomycota, such as Entomophthorales in our country. We have identified some species belonging to Entomophthorales and investigated cultural features and ecology of Entomophaga aulicae. E. aulicae in sweet potato fields, where Aedia leucomelas was a dominant pest, had caused epizootics from 2002–2005. E. aulicae-infected A. leucomelas larva were mostly found from August to October and its occurrence was significantly related to the precipitation. E. aulicae were mainly observed in dead A. leucomelas larval populations (infection rate = 41.3% in 2002), rather than other lepidopteran pests. E. aulicae was morphologically and genetically identified and its virulence was characterized in laboratory conditions. Additionally, pest infection by Zoophthora radicans, Neozygites floridana and some Entomophthorales have been identified. On the basis with this information, we need research to predict the prevalence and to develop biological control agent using Entomophthorales including E. aulicae that contribute to regulation of host populations.
        666.
        2014.10 구독 인증기관·개인회원 무료
        Enhanced green fluoresce protein gene (egfp) was expressed in Beauveria bassiana ERL836 based on the Agrobacterium tumefaciens-mediated transformation (AtMT) method in this study. The ERL836 transformants were generated with pCambia-egfp binary vector. Ten transformants were randomly selected and analyzed for the T-DNA insertion and gene expression. The results revealed that 60% of the fungal putative transformants were inserted by the T-DNA fragment. Of these transformants, 33.33% (2 transformants) expressed the egfp gene. The egfp transformants showed strong green fluorescence with different expression levels. The results of this study could provide a reference for foreign protein expression in B. bassiana by using the AtMT method.
        667.
        2014.10 구독 인증기관·개인회원 무료
        Mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae) has high and safe protein contents, which enables it to be animal feed. However, occurrence of entomopathogenic fungi in mealworms is one of the limitations for mass production. In this work, we investigated relationships between abiotic conditions and occurrence of fungal pathogens and established an effective control method using fungicides. In virulence assay, third instar mealworm larvae were sprayed by six entomopathogenic Beauveria bassiana isolates and kept under high relative humidity; B. bassiana ERL1575 isolate had highest virulence. Under normal humidity, ERL1575 conidia showed different virulence between spray (~0% virulence) and digestion (~80% virulence) method. Furthermore, mealworms, which digested conidia, were exposed to various temperature (20-35°C) and humidity (1-3 ml distilled water spray/35 mm diam. dish) conditions for 5 days. All the treatments showed ~90% virulence except 35°C incubations (~20% virulence), but irrespective to the humidity conditions. Forty chemical fungicides were assayed against conidial germination and hyphal growth of ERL1575. Fluazinam and mancozeb showed strong inhibition of conidial germination at standard application dose (SD), 1/2 SD and 1/5 SD; besides, fluazinam showed strong inhibition of hyphal growth. When fluazinam and mancozeb were applied to the fungal conidia-inoculated wheat bran, most of mealworms were alive after 3 days post application. However, high mortality rate (~100%) were observed in the conidia-inoculated wheat bran without any fungicides. In conclusion, this work suggests that B. bassiana isolates could be pathogens at <30°C when they were digested by mealworms, and fluazinam and mancozeb would be used as effective control agents against the pathogen.
        668.
        2014.10 구독 인증기관·개인회원 무료
        Bumblebees are important pollinators of crops and wildflowers. Bumblebees generally produce one generation per year. One of the key stages for year-round rearing of bumblebees is breaking diapause. To evaluate the effects of a combination method of CO2-narcosis and cold treatment to break the diapause of B. ignitus and B. terrestris queens, we determined whether this method affected their ability to establish a colony after the diapause break. The diapause treatment regimes that were utilized were CO2(CO2– narcosis), CT-1M(cold treatment at 5°C for 1 month), CT-1M-CO2(CO2–narcosis after cold treatment for 1 month), CT-2M-CO2(CO2–narcosis after cold treatment for 2 months), CT-2M (cold treatment for 2 months), CT-2.5M-CO2(CO2–narcosis after cold treatment for 2.5 months) and CT-2.5M (cold treatment at 5°C for 2.5 months). In view of the effects on the colony developmental characteristics of B. ignitus queens, the most favorable diapause treatment was CT-1M-CO2. A combination method of CO2– narcosis and cold temperature treatment yielded better results than that of single CO2–narcosis or cold temperature treatment on the colony development of diapause-broken B. ignitus queens. In the case of B. terrestris queens, we concluded that a combination method of CO2 and cold temperature treatment yielded better results than that of a single cold-temperature(up to2 months) treatment. In conclusion, the findings of the present study indicated that the combined application of CO2 and cold temperature was a favorable method for the colony development of diapause-broken B. ignitus and B. terrestris queens compared with only CO2–narcosisorcoldtemperaturetreatments. A combination method of CO2 and cold treatment reduced the side effect of CO2–narcosis and shortened the duration of cold treatment by at least 1month.
        669.
        2014.10 구독 인증기관·개인회원 무료
        The insecticidal activities of materialsderived from Dryopteris crassirhizoma Nakai against third instar larvae of three species mosquitoes (Culex pipiens, Aedes albopictus and Anopheles sinnensis) were evaluated using a direct contact mortality bioassay. The methanol extracts of D. crassirhizoma showed 100%, 87.8% and 100% larvicidal activity at 1,000 ppm against Cx. pipiens, Ae. albopictus and An. sinensis, respectively. Hexane fraction showed 100% larvicidal activity three species mosquitoes at 500 ppm after 24 hrs. Purification of the biologically active constituents from the hexane extraction with larvicidal activity was done using silica gel column chromatography. H1 and H3 fractions gave 100% mortality to Cx. pipiens, Ae. albopictus and An. sinensis at 100 ppm. H1 fraction separated with methanol to give a H111 through centrifugation. Fraction of the biologically active constituents from the H3 fraction with larvicidal activity was done using methanol. H31 fraction was determined 100% mortality to Cx. Pipiens, Ae. albopictus and An. sinensis at 50 ppm, respectively. Two fractions were analyzed C14H22O (H111, MW206.0) and C11H14O4 (H31, MW210.08) by GC and GC-MS. D. crassirhizoma derived compounds described herein could be useful for managing filed populations as larvicide of Cx. pipiens, Ae. albopictus and An. sinensis.
        670.
        2014.10 구독 인증기관·개인회원 무료
        Temperature and insecticide are two important factors that affect survival, reproduction and other physiological processes of insects. To determine interactions of temperature and insecticide treatment on susceptible (S) and imidacloprid-resistant strains (IMI-R) of Aphis gossypii, adults were exposed to three temperatures (17, 22, and 28℃) or combinations of three temperatures (17, 22 and 28℃) and imidacloprid (LC20), and the expression of several genes (heat shock protein 70, cuticle protein, cytochrome P450, and elongation factor) were analyzed. The expression level at 17℃ of heat shock protein 70, cuticle protein, and elongation factor in S strain were up-regulated with increased time and higher than those of IMI-R strain. However, expression of cytochrome P450 was not affected by elevated temperature both S and IMI-R strain. Combined treatment of elevated temperature and imidacloprid were significantly up-regulated only cuticle protein in S strain and higher than those of IMI-R strain.
        671.
        2014.10 구독 인증기관·개인회원 무료
        This study compared the development, reproduction, and DNA damage in insecticide (acequinocyl, bifenazate, and etoxazole)-resistant (AR, BR, and ER) and -susceptible (S) strains of Tetranychus urticae by electron beam irradiation. When eggs were irradiated with 150 Gy, the egg hatching was completely inhibited in all strains. When nymphs were irradiated, their emergence rate was decreased with increasing doses of electron beam irradiation. When adults were irradiated, the longevity and the number of eggs was not affected at all target dose in all strains. However, hatchability of F1 generation was perfectly inhibited at 400 Gy in all strains. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. These results suggest that electron beam irradiation induced abnormal development and reproduction in S, AR, BR, and ER strains of T. urticae.
        672.
        2014.10 구독 인증기관·개인회원 무료
        A novel oxidant fumigation (NOF) is a commercial bleaching and disinfection agent. Recent study indicates its insecticidal activity. However, its exact mode of action to kill insects is not known. This study sets up a hypothesis that reactive oxygen species released from NOF is a main factor to kill insects. Plodia interpunctella is a lepidopteran insect pest infesting various stored grains. Both larvae and adults were susceptive to NOF. To test the hypothesis, we needed to identify antioxidant genes in P. interpunctella. Superoxide dismutase (SOD) and thioredoxin-peroxidase (Trx) were identified from P. interpunctella EST library using ortholog sequences of Bombyx mori. Both SOD and Trx were expressed in larvae of P. interpunctella expecially against oxidative stress induced by bacterial challenge. The bacterial challenge also induced some heat shock protein (HSP) genes. Similarly, different doses of NOF significantly induced both SOD and Trx genes. There results suggest that NOF at sublethal doses releases reactive oxygen species, which may be detoxified by the antioxidant activities of SOD and Trx of P. interpunctella.
        673.
        2014.10 구독 인증기관·개인회원 무료
        The two spotted mite, Tetranychus urticae Koch, is a global pest, and has developed severe resistance to several types of acaricides. Acequinocyl-resistant strain and bifenazate-resistant strain of T. urticae showed higher relative activity level of glutathion-S-transferases (GSTs) than susceptible strain. Studies of resistance in T. urticae have focused on classical detoxifying enzyme system, such as GSTs. We examined the expression of six GSTs genes in T. urticae belong to five different cytosolic classes, including two in delta, one in omega, one in mu, one in zeta, and one mitochondrial GSTs class, kappa. RT-qPCR results showed that, among these six GSTs genes, the relative expression level of delta 1 was significantly higher in bifenazate-resistant strain than in other strains (susceptible, abamectin, acequinocyl, etoxazole and pyridaben strain). Expression level of the delta 2 was also higher in acequinocyl-resistant strain than in other strains. The elevated GSTs gene transcripts following exposure to acequinocyl, bifenazate might be one of the mechanisms involved in detoxification of these acaricide. These results may be caused by different mechanisms in the resistance development of T. urticae to these two different types of acaricides.
        674.
        2014.10 구독 인증기관·개인회원 무료
        A novel oxidant fumigation (NOF) has been considered as alternative fumigant to replace methyl bromide that is a serious ozone depleter. Its high oxidative activity has been used as a bleaching or sanitary agent. Though some reports an insecticidal activity of NOF, its insecticidal action is yet to be understood. This study was conducted with an observation of an insecticidal activity of NOF against Plodia interpunctella, which is a stored grain insect pest. Cytotoxicity test was performed by using MTT assay, NOF gave a significant cytotoxicity on both Sf9 cells and HiFive insect cell lines. Sf9 cells were higher susceptible (IC50 = 43.2+ 3.5 ppm) to chloride dioxide than HiFive cells (IC50 = 174.6 + 5.9 ppm). To understand its cytotoxic effect on P. interpunctella, the larval hemocytes were incubated in vitro with different doses of NOF for 40 min at room temperature. In a dose-dependent manner, NOF gave a significant toxicity to the hemocytes. When NOF was injected to larvae of P. interpunctella, it significantly reduced total hemocyte counts compared to control. These results indicate that NOF has cytotoxic effect against hemocytes of P. interpunctella. This hemolytic activity of NOF can be regarded as a lethal factor to the stored grain insect pest.
        675.
        2014.10 구독 인증기관·개인회원 무료
        To date there have been only two species in genus Pogonus and subgenus Europhilus of genus Agonum recognized from Korean insect fauna: Pogonus itoshimaensis Habu, 1954 and Agonum (Europhilus) bellicum Lutshnik, 1934. In the present study one additional species for each genus is newly recognized from Korea: Pogonus (Pogonus) japonicus Putzeys, 1875 and Agonum (Europhilus) gratiosum nipponicum Habu, 1972. A key to adults, redescription, diagnostic photos of adult and male and female genitalia are provided.
        676.
        2014.10 구독 인증기관·개인회원 무료
        In the present study, we report two lepidopteran pests on the cones of Abies koreana E. H. Wilson; Cydia sp. of Tortricidae and Dioryctria abietella Denis et Schiffermüller of Pyralidae. Larvae of these species bored tunnels inside the immature cones of the host plant. Damaged cones are easy to spot by reddish brown excretion from the pest entry holes, and the cones severly damaged by the larvae becomes crooked. Damage rate on the cones reached up tp 71% from the collection site. Regarding the two pests, some basic information such as collection records, morphological characters, and ecology were provided.
        677.
        2014.10 구독 인증기관·개인회원 무료
        Insect pollinators of the endanger orchid Cypripedium japonicum were surveyed and identified during two years, as a part of a conservation project of the orchid at Jukyeup-san and Hwaak-san (Mt.), South Korea. In total 40 individuals of 16 species in 4 families were identified. The dominant family was Halictidae, and Lasioglossum exiliceps Vachal visited the most frequently C. japonicum during the surveys. The average visiting frequency was 2.5 individuals per hour and the highest 4.3, from 12:00 – 13:00 in a day. After 15:00 insects did not visit the flowers at all. However, all of the visiting insects were found to not carry a pollinium or pollens of the orchard on their bodies; pollen carryover by any of the visiting insects did not occur at all. The orchid seems to require certain pollinators in particular body thickness due to its unique pollination mechanism. The orchid has two exit route openings, around 1 cm in diametre, where the entrapped insects can exit and an anther is situated just in front of each opening. It was inferred that a pollen carrier should be around 1 cm in body thickness. Therefore, the candidate species as the proper pollen carriers can be Tetralonia nipponensis Perez, Xylocopa appendiculata circumvolans Smith and Bombus consobrinus Dahlbom among the surveyed visitors.
        678.
        2014.10 구독 인증기관·개인회원 무료
        A partial sequence of the mitochondrial cytochrome oxidase subunit I (COI) gene is widely used as a molecular marker for species identification in animals, also termed a DNA barcode. However, the presence of more than one sequence type in a single individual, also known as heteroplasmy, is one of the shortcomings of barcode identification. In this study, we examined the extent and divergence of COI heteroplasmy, including nuclear-encoded mitochondrial pseudogenes (NUMTs), at the genomic-DNA level from 13 insect species, including four individuals of orthopteran Anapodisma miramae. Furthermore, a long fragment of mitochondrial DNA (~13.5 kb) and cDNA from A. miramae were used as a template for COI PCR to compare the patterns of heteroplasmy between DNA sources and to investigate a possible way to avoid ambiguity in DNA barcoding. When multiple numbers of clones originated from genomic DNA were sequenced, heteroplasmy was prevalent in all species (3~16 heteroplasmic copies), with a varying degree of maximum sequence divergence (<1% in 7 species, <4% in 3 species, <6% in 2 species and 2.15-8.03% in four A. miramae individuals). In five species, NUMTs also were observed when genomic DNA was used as a template. Long fragment DNA also is a source of heteroplasmic amplification, but the divergent haplotypes and NUMTs obtained in the genomic DNA-based PCR were not detected in A. miramae. On the other hand, cDNA was heteroplasmy-free, without NUMTs when multiple numbers of clones were sequenced. Consistently, one dominant haplotype was always obtained from the genomic DNA-origin clones in all species and also from the long fragment- and cDNA-origin clones of A. miramae. Furthermore, the dominant haplotype was identical in sequence, regardless of the DNA source. Thus, one possible solution to avoid the barcoding problem in relationship to heteroplasmy could be the acquisition of multiple numbers of barcoding sequences to determine a dominant haplotype that can be assigned as barcoding sequence for a given species.
        679.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A voltammetric investigation of Au assay was conducted at a low cost, using Nafion and DNA immobilized on a graphite Pencil working electrode (NDP) with a black lead counter and reference. The following optimal parameters were found: 0.4 V amplitude, 500 Hz frequency, -0.7 V initial potential, and 0.015 V increment potential. These optimal conditions were also applied to sand obtained from the river site. The aforementioned technique is simpler and less costly compared to the common voltammetry and spectrophotometric methods.
        4,000원
        680.
        2014.07 구독 인증기관·개인회원 무료
        Social media users today have become active producers of information but how sharing brand-related information affects the attitude of other users is an important and unexplored path. Narayan et al. (2011) mentioned that User’s attitude towards the brand is shaped not just by the attributes of the products but also the preferences of other consumers, such as peers. Zhu et al. (2012), through their study concluded, user’s opinions significantly sway other user’s own choices or are likely to reverse their attitudes. Dawson et al. (1990) have supported that delivering experiences that are pleasurable and relevant will linger in the memory and influence the user’s attitudes and purchase intentions. Although previous studies researched the attitude of the users towards social media advertising, the effect of social media advertising on the user’s attitude towards the brand is yet to be examined. By applying the Uses & Gratification theory, stimulus-Organism-Response theory and the Theory of Reasoned Action, this study aims at evaluating the effects of information sharing, peer pressure, entertainment and emotional connection in a social media setting on the user’s attitude toward a brand present in social media thereby influencing their purchase intentions from the brand. An online survey was developed using items adopted from previous study and administered to college students, who are regular users of social media, such as Facebook, Twitter, and YouTube. Of 271 valid responses, 21% were males and 79% were females. Multiple regression analyses results supported all hypotheses. The results are consistent with the previous research, confirming user’s choice of media is influenced by their information seeking, entertainment and status needs (Tan, 198). Marketing via social media may offer content that have specific relevance or may offer entertainment for users (Chi, 2011) and may result in the establishment of an emotional connection with the brand. The more frequently brands interact with the users/fans/followers, the stronger will be the emotional connection which will affect the user’s purchase intentions from the brand. MaKenzie, Lutz & Belch (1986) in their study supported that the marketing patterns can influence the attitude of the users towards the brands which in turn affects the purchase intentions from the brand. The findings of this study confirmed that social media is a very important marketing tool. The marketers needs to ensure that they a) have a presence and social media, b) devise effective online marketing strategies and c) employ dedicated social media staff to continually interact, entertain and engage the users.