검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 58

        21.
        2019.12 KCI 등재 구독 인증기관·개인회원 무료
        미국선녀벌레에 방제효과가 높은 3종 (데리스, 시트로넬라, 계피)의 식물추출물과 보조제 (잔탄검과 실리콘 계열 화합물)를 함유하는 조성물을 개발하였다. 이 조성물은 인삼 재배지에서 미국선녀벌레 방제효과가 90% 이상으로 높았다. 또한 다른 흡즙성 해충에도 살충률이 높아 PLS (positive list system) 전면 시행에 따른 대응방안으로 활용이 가능할 것으로 생각된다.
        27.
        2019.04 구독 인증기관·개인회원 무료
        The beet armywom, Spodoptera exigua Hübner, originated from Southeast Asia is one of important agricultural pests worldwide. The moth having no diapause mechanism has highly migratory capacity which contributes to population outbreaks and geographic expansion. Although the moth was first reported in 1926 from Korea, it has been important since the late 1980s. In July 2018, the species outbreaked in Gimje, Jeonbuk Province causing serious damage to soybean in several paddy fields. In this study, we investigate the genetic diversity of the outbreaking populations using a partial sequence of mitochondrial DNA COI gene. 37 COI sequences obtained from specimens collected at the fields of Gimje, Korea were compared with 249 COI sequences from GenBank. In total, 25 haplotypes were detected from 18 countries. Three haplotypes (H1, H2, and H5) found in Korea were all shared with those in China. Haplotypes H1 and H2 were prominent in Korea as well as in invasive regions worldwide. This suggest that outbreaking populations in Korea were invaded from China. The migration source was estimated using backward trajectory analysis, and found to be Zhejiang Province, China.
        28.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Excessive intake of red meat has been associated with colon carcinogenesis. The effect of hemin and zinc on colon carcinogenesis was investigated in male ICR mice. After acclimation for 1 week, five-week-old mice received three s.c. injections (0-2nd weeks of the experiment) of azoxymethane (AOM; 10 mg/kg b.w.) weekly and were treated by 2% dextran sodium sulfate (DSS) in drinking water for the next 1 week to induce aberrant crypt foci (ACF). Mice were fed on AIN-76A purified rodent diet for 6 weeks. There were three experimental groups; control, hemin, and hemin + zinc groups. The daily oral doses of hemin and zinc were 534 mg/kg and 55 mg/kg b.w., respectively. After staining colonic mucosa with 0.2% methylene blue, the ACF, aberrant crypts (AC), and polyps were counted. Lipid peroxidation in liver was evaluated by thiobarbituric acid-reactive substances (TBARS) assay. The numbers of AC, ACF, large ACF (i.e., ≥4 AC/ACF), and polyps in the hemin group were higher than those in the control group. In hemin + zinc group, the numbers of AC, ACF, large ACF were significantly lower compared to the hemin or control groups (p < 0.05), and the number of polyps was also significantly lower compared to that in the hemin group (p < 0.05). The TBARS level in the livers of the hemin + zinc group was significantly lower than that of the hemin group (p < 0.05). These results suggest that hemin enhances colon carcinogenesis and that co-treatment with zinc can protect against the induction of colon carcinogenesis.
        4,000원
        29.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Clostridium perfringens (C. perfringens) may cause diarrhea and enterotoxemia in adult and young livestock, leading to problems in the production and management of farms. Four hundred fecal samples were collected from 25 goat farms located in Gyeongsangbuk-do Province in the Republic of Korea. Sixteen C. perfringens strains were isolates from fecal samples, and the isolates were identified as type A (n=11) and type D (n=5). Additionally, α- and ε-toxin genes were detected in 16 and 5 strains by PCR, respectively, and the enterotoxin gene was presented in 2 strains. The antibiotic susceptibility test was performed using the disk diffusion method and E-test method. In the disk diffusion method, ampicillin (n=16) and chloramphenicol (n=15) were highly susceptible to 16 C. perfringens isolates. In the E-test method, ampicillin, amoxicillin, amoxicillin/clavulanic acid and meropenem were susceptible to more than 14 of 16 C. perfringens isolates. This study indicates that administration of antibiotics such as ampicillin, amoxicillin/clavulanic acid and meropenem can prevent and treat C. perfringens infections in goats.
        4,000원
        30.
        2018.10 구독 인증기관·개인회원 무료
        Until recently, Thrips setosus Moulton, 1928 (Thysanoptera: Thripidae) has been regarded as endemic to Japan, occurring in open and greenhouse fields. The thrips causes direct feeding damage as well as transmits Tomato spotted wilt virus (TSWV) to agricultural vegetables and ornamentals. In 2014, it was found on Hydrangea in the Netherlands and then also confirmed as a invasive pest in the other European countries such as France and Germany. Interestingly, Hydrangea originated in Southern and Eastern Asia has not previously been recorded as a host plant. In Korea, since its first discovery in a commercial Hydrangea greenhouse in Gimje, Jeonbuk Province this year, the species was additionally found on the same crop in Jeonnam and Gyeonggi Provinces. Occording to the farmers, all Hydrangea plants has been imported from the Netherlands. Molecular phylogenetic study using COI partial gene strongly suggests that the thrips may have recurrently invaded with infested Hydrangea plants from Europe.
        31.
        2018.04 구독 인증기관·개인회원 무료
        Thrips setosus Moulton, 1928 (Thysanoptera: Thripidae), one of the Tospovirus vectors, was found at a commercial greenhouse in Korea. It damaged to leaves of hydrangea (Hydrangea macrophylla). The thrips widely distributes in Japan, being regarded as its origin. Recently, it invaded in Europe such as the Netherlands, France, and Germany. Unlike Japan, it was found on Hydrangea plants in European countries. In Korea, the thrips was recorded in 1974 by Woo. However, examination of voucher specimens reveals that the record is not true. According to the collection data since 2000, its distribution in Korea is rarely limited in Jeonbuk and Jeju. For identification, representative morphological characteristics and COI barcoding results are provided with possibility of introduction from Europe.
        32.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Colorectal cancer (CRC) is the third most prevalent cancer in the world, and heme iron is known to promote the CRC in an animal model. This study was conducted to investigate the effects of ascorbic acid in the presence of hemin on the formation of pre-neoplastic lesions induced by azoxymethane (AOM)/disodium sulfate (DSS) in mice. After acclimation for 1 week, five-week old mice received three s.c. injections (0-2 weeks of the experiment) of AOM [10 mg/kg body weight (BW)] weekly and were treated with 2% DSS in drinking water for the next week to induce aberrant crypt foci (ACF). All animals were fed the AIN-76A purified rodent diet for experimental period of 6 weeks. Experimental groups were then divided into three groups: carboxymethylcellulose (CMC) alone (control), CMC + Hemin, CMC + Hemin + ascorbic acid (AA). The CMC was used as a solvent for hemin. The daily doses were 534 mg/kg BW hemin and 246 mg/kg BW ascorbic acid administered orally. After the colonic mucosa were stained with methylene blue, aberrant crypt foci (ACF), aberrant crypt (AC) and polyps were counted. Lipid peroxidation in liver was evaluated by the thiobarbituric acid-reactive substances (TBARS) assay. The numbers of ACF, AC and large ACF (≥4 AC/ACF) per colon increased in the hemin group compared to the control group, while they decreased significantly in the hemin + ascorbic acid group compared to the control group or hemin group (p<0.01). The number of polyps/colon in the hemin + AA group was significantly decreased compared to the hemin group (p<0.05). In the liver, the TBARS value of the hemin group was significantly higher than that of the control group (p<0.01). Additionally, the TBARS value of the hemin + AA group decreased slightly compared to that of the hemin group. Taken together, these results suggest that hemin can promote colon carcinogenesis in a mouse model and that ascorbic acid has a protective effect against hemin-promoted colon carcinogenesis.
        4,000원
        33.
        2017.10 구독 인증기관·개인회원 무료
        The diamondback moth, Plutella xylostella is one of the world’s major pests. Economic cost to control this pest wasestimated between US$1.3 billion and US$2.3 billion based on management costs. Conservative estimate included yieldloss caused by 5% diamondback moth was estimated US$4 billion-US$5 billion. P. xylostella was managed by chemicalinsecticide such as organophosphates, carbamates and pyrethroids. But insecticide resistance which is caused by repeatedapplication makes it difficult to control this pest. For environmental friendly control of diamondback moth, entomopathogenicfungi could be used as alternative. We conducted bioassay to select high virulent isolate to larva of diamondback mothwith forty six entomopathogenic fungi which were isolated from soil samples by insect-bait method. As a result of bioassaytwelve isolates was selected as candidate. We investigated control efficacy of these twelve isolates with potted Chinesecabbage at laboratory and greenhouse.
        34.
        2017.04 구독 인증기관·개인회원 무료
        Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.
        35.
        2017.04 구독 인증기관·개인회원 무료
        Maruca vitrata larvae feed on flowers and pods of several leguminous crops, and can severely reduce seed yield. Adult emergence, mating and oviposition behaviors were observed in a 15h/9h=light/dark and 25℃ condition as a base study for monitoring. Emergence occurred mainly during the first five hours of scotophase. Mating occurred from the two days after emergence, and the mated females started to lay eggs from the next day. A maximal mating rate was observed in the night of five days. Mating occurred significantly more often during the time from 2 hours before to 3 hours after lights-off, but older females mated more frequently during the photophase. Electroanntennographic responses of males to some chemicals, and body extracts and volatile collections of females were measured
        36.
        2016.07 구독 인증기관 무료, 개인회원 유료
        Firms acquire customers using myriad forms of marketing media (Neslin & Shankar 2009), and different media strategies yield different results to the firms. Therefore, allocating media strategy given a firm’s spending raises important questions for managers. This is especially the case since the media landscape has changed dramatically, with new media channels incorporating online, mobile, and social media now being considered the mainstream. It is crucial to understand how each form of media influences consumers and how it operates alongside traditional media. Based on Stephen and Galak (2012), marketers distinguish earned media from paid media. Earned media is defined as media activity that a company does not directly generate, such as press mentions on the internet and online community posts in consumer-generated social media. On the other hand, paid media refers to the media activity which a company generates (for example, television, radio, print, and direct mail). It is common for firms to consider using earned media and paid media at the same time when developing marketing communication strategies. Despite the coexistence of paid and earned media channels, previous empirical findings focus either on paid media or earned media and suggest that these individually will increase a firm’s marketing outcomes. However, there is a lack of research that examines the question of whether the use of paid media and earned media at the same time is synergistic. The effects of a cross media synergy only focuses on the resource allocation within paid media (for example, TV–Radio (Edell & Keller 1989), TV–Magazine (Confer & McGlathery 1991), TV–Print (Dijkstra, Buijtels, & Van Raaij 2005), and TV, Radio, Print and Outdoor (Briggs, Krishnan, & Sheeran 2003)). Thus, by considering paid media and earned media concurrently, this study investigates whether the synergies between paid and earned media have a stronger effect on a firm’s long term profitability than the isolated effects of TV or word of mouth (WOM) alone. In addition, the research on earned media has focused on short-term outcomes such as customer actions (for example, website sign-ups) and sales growth, sales rank, cross-product sales, and ratings (Trusov, Bucklin, & Pauwels 2009; Li & Hitt 2008; Moe & Trusov 2011). Moreover, in the limited research on the relationship between earned media and long-term outcomes, the outcomes are restricted to those related to soft metrics of communication effectiveness (for example, attitude and brand awareness). Therefore, we use customer equity, which is regarded as a forward looking firm outcome variable, thereby enabling marketers to monitor and measure the long-term financial impact of marketing spending (Kumar & Shah 2015). Moreover, cross-media synergy can be accurately measured by customer equity, which incorporates both customer acquisition and retention. Based on Villanueva, Yoo, and Hassens (2008), customers acquired through paid media focus more on trials, whereas customers acquired through earned media provide the firm with more repeats. In other words, paid media plays a key role in the acquisition of customers, while, on the other hand, earned media increase the retention of customers. Thus, it is appropriate to measure the cross-media synergy with the customer equity (long term profitability) that can capture the customer acquisition and retention simultaneously. Regarding the long term impact of the firm’s media strategy, previous research has used the economic impact of traditional marketing channel (for example, television, radio, magazine or newspaper, advertisement, e-mail links, and direct mail) versus that of WOM (for example, links from Web sites, magazine, or newspaper articles, referrals from friends or colleagues, referrals from professional organizations or associations, and referrals from search engines) on customer equity. Traditional marketing had a stronger effect than WOM in the short term, while WOM is a quiet, gradual-impact, long lasting driver (Villanueva, Yoo, & Hassens 2008). This result can be attributed to the different characteristics of each media channel. Although earned media, including WOM, is not entirely controlled by the firm, earned media may be more likely to last longer for various reasons. One of the reasons for this phenomenon is that earned media has greater credibility than conventional marketing activities that are implemented by the firms, and is therefore more persuasive than conventional advertising (Brown & Reingen 1987, Villanueva, Yoo, & Hassens 2008). In other words, considering the impact of each type of media in itself, earned media is more effective in increasing long-term profitability. However, the interaction effect of earned and paid media has not been empirically tested yet. Thus, it is conceivable that a cross-media synergy (incorporating the implementation of earned media and paid media at the same time) will last longer than the implementation of each isolated media. As Armelini and Villanueva (2010) pointed out, earned media and paid media have complementary effects. For example, offline advertising increases website visitation by influencing consumer awareness, while online advertising directly leads to website traffic (Ilfeld & Winer 2002). The consumer buying process involves distinct stages such as awareness, consideration, and purchase (Lavidge & Stener 2000) and each media influences customer buying behavior in a different way. Hence, it enhances the effectiveness in terms of long-term profitability to utilize the cross-media effect properly. For example, in the car industry, 64 % new car buyers become aware of the features and benefits of a car by obtaining information online, even though they purchase their cars from an offline dealership (J.D. Power and Associates 2004). This finding implies that a firm’s implementation of both paid and earned media properly will maximize the customers’ arousal of the target brands. Furthermore, converging paid media and earned media is expected to proliferate the growth of a firm’s profitability, such as sales, revenue, and customer’s equity, at an exponential rate. For example, the effects of TV advertising execution can be enhanced by press mentions that a company does not directly generate; this is because press mentions support the credence of TV advertising. Inversely, since paid media activities reach the audience relatively more than WOM (due to the high audience penetration share), the online share of press mention can proliferate rapidly with the execution of paid media activities. Therefore, the interaction between earned media and paid media has a greater effect on customer equity than isolated media implementation. The impact of a media synergy has more positive effect and last longer than isolated media implementation (and our model is displayed in Fig. 1). We collect data on marketing efforts, word-of-mouth circumstance, and performance of a telecommunication company. Based on customer equity models and quarterly marketing and performance data, we first estimate the lifetime value of the newly acquired and existing customers. Thereafter, we determine the customer equity of the company over each period. We develop and employ a time-series model for examining the relationship between cross media efforts (paid media vs. earned media) and the estimated firm’s customer equity. Finally, we examine the synergistic effect of cross media on the firm’s long-term profitability.
        3,000원
        37.
        2014.10 구독 인증기관·개인회원 무료
        The insecticidal activity of cinnamon essential oils, cinnamon bark, cinnamon technical, cinnamon green leaf oils and their constituents and structurally related compounds against citrus flatid planthopper, Metcalfa pruinosa, was examined using a direct contact application. At 500 mg litre-1 very strong mortality (100%) was observed in cinnamon technical, cinnamon bark, cinnamon green leaf, mortality against flatid planthopper M. pruinosa. The cinnamon oils constituents were identified by GC-MS. The active principles were determined to be hydrocinnamic acid (24 h LC50, 30.66 mg/L), geranic acid (24 h LC50, 31.23 mg/L), cinnamaldehyde (24 h LC50, 32.65 mg/L), hydrocinnamaldehyde (24 h LC50, 39.11 mg/L) and trans-cinnamaldehyede (24 h LC50, 39.54 mg/L) were the most toxic against both nymph and adult of citrus flatid planthopper, M. pruinosa. The moderate activity was observed with cinnamyl acetate, dibutyl pthalate, anethole, α -cyano cinnamic acid, cinnamyl alcohol, methyl cinnamaldehyde, eugenol, 2.4-dihydrocyl cinnamic acid, bornyl acetate (24 h LC50, 53.35- 97.17 mg/L) respectively. The other constituents were showed less or no activity against adult of M. pruinosa. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the active cinnamon oils active principles act as potential insecticides for the control of M. pruinosa populations as direct spray with contact action.
        40.
        2012.06 구독 인증기관 무료, 개인회원 유료
        Iron is an essential trace element for normal functions of the body. Restriction of iron availability directly limits erythropoiesis. The objective of this experiment was to compare the bioavailability of iron nanoparticles (Fe-NPs) with iron-microparticles (Fe-MPs) in anemic mice. There were four experimental groups, including the normal control group, iron-deficiency anemia (IDA) group, Fe-NPs group, and Fe-MPs group. Animals in the normal group fed on an adequate iron-containing diet (45 ppm Fe). Meanwhile, animals in the other three groups fed on a low Fe diet (4.5 ppm Fe) for seven weeks. Double deionized water was supplied as drinking water ad libitum. After feeding for three weeks with the low Fe diet, animals in the Fe-NPs and Fe-MPs groups received oral administration of Fe-NPs or Fe-MPs at a daily dose of 40 mg/kg for four weeks. The IDA group showed markedly decreased red blood cell (RBC) count, hematocrit (Hct), and hemoglobin (Hb) values compared with the normal group throughout the experimental periods. Treatments with Fe-NPs or Fe-MPs for four weeks resulted in restoration of the decreased RBC count and hematological values similar to normal values. The Fe-NPs group showed faster restoration in values than Fe-MPs with passage of time. The iron contents of the upper small intestine in the Fe-NPs and Fe-MPs groups were higher than in the normal group at weeks 2 and 4. Treatment with Fe-NPs and Fe-MPs resulted in a significant increase in hepatic iron contents and lipid peroxidation, compared with the IDA group with passage of time. The iron contents in liver and ferritin deposits in spleen were identified in the Fe-NPs and Fe-MPs groups, similar to the normal group. These results indicate that oral administration of both Fe-NPs and Fe-MPs can result in recovery from anemia and Fe-NPs is more absorbable and available in the body than Fe-MPs.
        4,600원
        1 2 3