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        검색결과 123

        61.
        2017.04 구독 인증기관·개인회원 무료
        We performed a survey for flavivirus infection and distribution of Aedes albopictus that known as Zika and Dengue virus vector using black–light trap and BG-sentinel trap around urban area in Korea. Mosquitoes were collected in 27 cities during March to November (twice a month) year 2016. Total numbers of mosquitoes collected 102,102 including 19 species 8 genera during collecting period. Total 21,467 Ae. albopictus was collected that 20,961(24.3%) by BG-sentinel trap and 506 (3.2%) by Black-light trap in urban area. Trap index(trap/night) of Ae. albopictus was showed highest in Hamyang (TI:992.3) and lowest in Taebaek (TI:0.3) there was only collected by Black-light trap. A total of 894 pools from all collecting Ae. albopictus were performed a Flavivirus detection. Flavivirus was not detected during study period. This study may provide basic information for surveillance of imported diseases (include Zika virus) and vectors in Korea.
        62.
        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
        64.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Colorectal cancer is one of the most common types of cancer in men and women who consume a Western diet. We investigated the inhibitory effect of selenium (sodium selenite, Na2SeO3) and selenium nanoparticles (nano-Se) on experimental colon carcinogenesis in ICR mice. After a 1-week acclimation, 6-week-old mice received three intraperitoneal (i.p.) injections (experimental week 0-2) of azoxymethane (AOM, 10 mg/kg body weight, b.w.), followed by 2% dextran sodium sulfate (DSS)-containing drinking water for the next 1 week. The three groups (10 mice/group) were orally administered either distilled water (control), selenium (1.7 ppm), or nano-Se (1.7 ppm) daily for 8 weeks. The numbers of aberrant crypt foci (ACF), aberrant crypt (AC), and tumorous lesions were measured in colonic mucosa. Se and nano-Se treatments significantly decreased the number of ACF, AC, and tumorous lesions compared with the control. However, there was no significant difference between the selenium and nano-Se groups. The glutathione peroxidase (GSH-Px) activity in the liver and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in serum, were high in the selenium and nano-Se groups, while thiobarbituric acid reactive substance (TBARS) level was low in both Se and nano-Se groups when compared with that in the control group. These findings indicate that selenium and nano-Se showed similar protective effects against colon carcinogenesis by inhibiting the development of ACF and tumorous lesions in mice.
        4,000원
        65.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Iron-overload can cause harmful effects such as cancer and aging via promoting the production of free radicals. The effect of orally administered nano-Fe overload with ascorbic acid on colon carcinogenesis was investigated in male ICR mice. After a 1-week acclimation, 5-week-old mice received three intraperitoneal injections (experimental week 0-2) of azoxymethane (AOM, 10 mg/kg body weight) weekly, followed by 2% dextran sodium sulfate (DSS) in drinking water for the next 1 week to induce aberrant crypt foci (ACF). Animals were divided into four groups; carboxymethylcellulose (CMC) alone (control), CMC + ascorbic acid (AA), CMC + nano-Fe (NFe), and CMC + NFe + AA groups. Animals were fed an AIN-76A purified rodent diet and daily administrated oral doses of 450 ppm each of nano-Fe and AA combination for 6 weeks. The colonic mucosa was stained with 0.5% methylene blue, and then the ACF and polyps were counted. Lipid peroxidation in the serum and liver was evaluated using the thiobarbituric acid-reactive substances (TBARS) assay. Iron concentration in the liver was measured using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Iron concentration in the liver of the NFe-overloaded groups was higher than that of the control (p<0.05). AA treatment increased the iron concentration in the liver. The number of ACF was not significantly different among all the groups. The number of polyps in all the NFe-treated groups was slightly higher than that in the control group and AA only-treated group. The serum TBARS was not significantly different among all the groups, but that in the liver was higher in all the NFe-treated groups than it was in the control group (p<0.05). These results indicate that the additional NFe treatment did not affect the experimental colon carcinogenesis in mice regardless of the presence of ascorbic acid.
        4,000원
        66.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 7년(2009-2015)간 한반도 주변을 통과한 태풍의 이동 경로에 따른 수온의 변동을 분석하였다. 자료는 위성관측 수온영상, 동해 연안의 양양, 강릉, 삼척, 영덕에서 실시간 계류부이에서 관측한 수온과 기상청에서 제공한 바람을 분석하였다. 위성 영상을 이용한 태풍 통과 전후의 근해 수온의 차이는 태풍의 이동 경로에 따른 바람의 방향뿐만 아니라 해면 가열과 해면 상승의 시기와도 관계가 깊게 나타났다. Muifa, Chanhom, Nakri, Tembin과 같은 태풍들의 오른쪽에 위치한 동해 연안의 수온은 남풍계열의 바람에 의한 연안 용승으로 표층뿐만 아니라 15m, 25m의 수온까지 하강하는 것을 알았다. 특히, 태풍 Chanhom과 Tembin에 의한 수온의 하강은 각각 8-11℃와 16℃ 하강하였다. 한편 그 반대편에 태풍이 위치할 때는 외해쪽에 있는 고온의 해수를 연안쪽으로 이동하여 침강시킴으로서 중층과 저층의 수온이 상승하였다. 또한, 태풍 통과 이후에 동해 연안에서 남풍(북풍)계열의 바람에 의한 하강(상승)된 수온의 혼합은 1-2일 및 4일간 지속되었다.
        4,500원
        67.
        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
        68.
        2016.04 구독 인증기관·개인회원 무료
        Beet armyworm, Spodoptera exigua, diamondback moth, Plutella xylostella and tobacco cutworm, Spodoptera litura are the three most serious pests of many economically important crops such as cruciferous crops, various vegetables and ornamental plants. Because these pests are known to be resistant to lots of chemical insecticides, integrated control using both or either entomophathogen and/or natural enemy is thought to be an attractive alternative for effective control. One of the obstacles using and expanding mycopesticide is narrow host ranges. At commercial farms, cultivating crops are seriously damaged by various Lepidopteran pests. Farmers want to use a microbial control agent which can control various host insects to reduce cost and labor. In previous study, we selected two entomopathogenic fungi, Metarhizium anisopliae and Paecilomyces fumosoroseus, which shown high virulence against beet armyworm. For wide use of the isolates in farm, we tested its host ranges, especially to diamondback moth and tobacco cutworm, which also are serious pest in Korea. The two isolates were shown a good control effect in leaf disc bioassy.
        69.
        2016.04 구독 인증기관·개인회원 무료
        Pheromone biosynthesis-activating neuropeptide (PBAN), produced in subesophageal ganglion, is known to stimulate pheromone biosynthesis in Plutella xylostella. The pheromone production is more active in the scotophase than in the photophase, which suggests that there may be changes of gene expression in the pheromone glands. To analyze gene expression involving in pheromone biosynthesis for 24 hrs, we performed transcriptomes of pheromone glands which were isolated at every 4 h. Eleven pheromone biosynthesis-related genes, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, Δ9 desaturase, Δ11 desaturase, fatty acid reductase (FAR), alcohol oxidase, aldehyde oxidase, and aldehyde reductase were identified. Among these genes, ACC, FAS and chain shortening enzymes involving in early stage of pheromone biosynthesis exhibited their highest expression between AM9 and PM5. Desaturases, Δ9 and Δ11, showed the peak of expression at PM1 and AM5 or PM5, respectively. Interestingly, FAR expression was the highest at AM1, active reproductive period. These results suggest that genes involving in pheromone biosynthesis can be sequentially regulated for their biological roles.
        70.
        2015.10 구독 인증기관·개인회원 무료
        The pheromone biosynthesis in Plutella xylostella is stimulated a neuropeptide, pheromone biosynthesis activating neuropeptide which is produced in subesophageal ganglion. The pheromone production is more active in the scotophase than in the photophase, which suggests that there may be changes of gene expression in the pheromone glands. To analyze gene expression related to pheromone biosynthesis, we performed transcriptomes of pheromone glands which were isolated at every 4 h. Eleven pheromone biosynthesis-related genes, acetyl-CoA carboxylase, fatty acid synthase, acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, Δ9 desaturase, Δ11 desaturase, fatty acid reductase, alcohol oxidase, aldehyde oxidase, and aldehyde reductase were identified. Among these genes, the expression of aldehyde reductase and aldehyde oxidase were relatively higher in the scotophase than in photophase, which may affect increase of pheromone production in the scotophase. Expression of signal genes involving in pheromone biosynthesis such as acyl-CoA desaturase, FAR, PBAN receptor, fatty acid transporter and acyl-CoA binding protein did not exhibited any significant difference.
        71.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To determine the movement of degradable HGC nanoparticles in the body, 20 mg/kg of lutetium177-labeled HGC (Lu177-HGC) with the size ranging from 320 to 400 nm was injected intravenously into ICR mice, and the amount of radioactivity remaining in blood and several organs was measured at various time points during the period of 5 days. In the pharmacokinetics analysis using the Lu177 radioisotope, the free Lu177 was mainly distributed and accumulated in the order of kidney>liver>lung at 1 day after the injection of the radioisotope. However, the Lu177-HGC showed a high distribution of nanoparticles in the order of liver>spleen>kidney during the experimental period of 5 days. These results would provide a basic pharmacokinetics for the use of HGC as a drug carrier in drug delivery system.
        4,000원
        72.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ultimate goal of this study is to assess the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To understand the movement of degradable nanoparticle HGC in the body, we intravenously injected a dose of 20 mg/kg of Cy5.5-labeled HGC with size ranging from 320 to 400 nm into ICR mice, and measured the amount of fluorescence remaining in blood and several organs at various time intervals. In blood, the level of Cy5.5-labeled HGC was the highest at 15 min, then after 30 min it decreased rapidly and reached a plateau form 30 min to 28 days. In the tissue we confirmed the presence of nanoparticles at high levels in the order of kidney>liver>submandibular gland until 28 days after injection. However, we did not find the presence of the particles in the brain or testes. These results will provide basic information on HGC as a drug delivery agent.
        4,000원
        73.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Landscape and natural monuments protection policy in North Korea is rarely understood because of lack of information in scientific and legislative fields. Legislative system is very important to protect landscape and natural monuments, which are described at “Landscape and natural monuments protection law (LNMPL)” in North Korea. Cabinet of North Korea has authorities to lead the Central Agency for Landscape and Natural Monuments Protection (CALNMP). Designation and managements of landscape and natural monuments are regarded as CALNMP’s and local governments’ responsibilities. There are many differences between South and North Koreas’ landscape and natural monuments protection system. Especially legislation system has profound differences in its legal structure. North Korea’s Labor Party is superior to the Cabinet and Labor Party’s administrative order has at least the same authority to regulate and manage the national policy and means. With LNMPL, CALNMP organizes the national plan for landscape and natural monuments protection and regulate the activities of the Agencies for landscape and natural monuments protection in the aspects of action plan for each administrative agency, budget and other resources. For the reunification in the future and economic cooperation, legislative and administrative system of landscape and natural monuments protection in North Korea should be understood.
        4,300원
        74.
        2015.04 구독 인증기관·개인회원 무료
        The pheromone biosynthesis in Plutella xylostella is more active in the scotophase than in the photophase, which suggests that there may be changes of gene expression in the pheromone glands. To identify genes contributing to change in pheromone production, we analyzed transcriptomes from pheromone glands of both decapitated females in the photophase and normal ones in the scotophase. Comparative analysis were performed with transcriptomes of pheromone glands from non-decapitated (PG) females and decapitated ones for identification and expression of putative genes associated with pheromone biosynthesis pathway. Deep sequencing for mRNAs in the pheromone gland yielded approximately 7.5Gb and totally 17265 transcript were constructed under a homology cutoff of 10-6 Evalue. Genes putatively involved in pheromone biosynthesis were identified such as acetyl-CoA carboxylase, acetyl-CoAdehydrogenase, fatty acid synthase (FAS), desaturases (Δ9 and Δ 11) and fatty acid reductases (FAR) including pgFAR, alcohol oxidase, aldehyde oxidase and aldehyde reductase, etc. Expression of 6 signal genes involving in pheromone biosynthesis such as acyl-CoA desaturase, FAR, PBAN receptor, fatty acid transporter, acyl-CoA binding protein did not exhibited ant significant different in both transcriptomes. Quantitative RT-PCR revealed that expressions of FAS, Δ11 desaturase and pgFAR were higher in PG than that in ΔPG. Based on results, Δ11 desaturase and pgFAR may have a crucial role in sex pheromone biosynthesis of P. xylostella.
        75.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 북한의 「바다오염방지법」에 대해 법적․경제적 함의에 대해 분석하였다. 이를 위해 북한의 관련법령과 우리 나라의 법률, 제한적인 정보와 기존 연구문헌을 통해 비교분석하였다. 「바다오염방지법」은 북한의 해양환경관련법령 중에서 기본법의 성격을 가지고 있다. 그러나 남한의 관계 법률과 달리, 「바다오염방지법」은 환경권이나 행복권 추구라는 민주시민의 기본권리 보장보다는 해양오염방지를 통한 자원의 확보를 강조하고 있다. 또한 각급 국토환경보호기관(관련기관, 기업체, 단체 포함)의 실질적인 정책시행 등에 대한 제반규정이 적다. 북한의 법령체계의 특수성을 고려한다고 하더라도, 실행체계에 대한 미비로 인해 법의 실효성에 문제가 있을 것으로 판단된다. 이 법의 경제효과분석을 위해서는 자료축적이 필요하다. 향후 통일을 대비한 남북한의 법령제도통합을 위해서는 비교적 이념중립적인 환경관련법령을 통한 접근이 중요하다.
        4,000원
        76.
        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.
        77.
        2013.10 구독 인증기관·개인회원 무료
        The insecticidal activity of 120 plant essential oils and control efficacy of six experimental spray formulations (SF) containing the oils (SF-0.25, 0.5, 1, 2.5, 5 and 10% sprays) against both nymph and adult of citrus flatid planthopper, Metcalfa pruinosa, was examined using a direct contact application. Reponses varied according to dose (1000 mg litre-1 and 500 mg litre-1). Based on 24 h exposure in leaf dipping assay at 1000 mg litre-1 strong mortality was observed in more than 19 essential oils among 130 was screened. At 500 mg litre-1 very strong mortality (100%) was observed in cinnamon technical, cinnamon green leaf, cinnamon #500, cassia tree, citronella java and penny royal followed by origanum, thyme white, grape fruit, savory, fennel sweet, aniseed and cinnamon bark (93.3- 80%) showed considerable moratality against nymphs of M. pruinosa. The moderate mortality was found in thyme red, tagette, calamus, lemoneucalptus and geranium (73.3-60%). The other oil has low or very low mortality against M. pruinosa. The oil applied as SF-10% sprays provided 100% mortality against adult M. pruinosa. In particular cinnamon technical showed very strong (>SF-0.5= 100%) effect followed by cinnamon #500 (>SF-2.5=100%), cinnamon green leaf (>SF-2.5=100%) and penny royal (>SF-2.5=100%) respectively. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the active essential oils as potential larvicides for the control of M. pruinosa populations as direct spray with contact action.
        79.
        2013.06 구독 인증기관 무료, 개인회원 유료
        Clay dispersion has been applied in Korean coasts since 1996 to minimize fisheries impact by Cochlodinium polykrikoides blooms. Understanding of spreading and sedimentation pattern of yellow clay in the sea after dispersion would be helpful for the counter measure of possible impact on marine environment and ecosystem by the clay. Tidal current movement and sedimentation of clay targeted on Obido island, Tongyong, Korea where clay had been frequently introduced to control red tide was calculated based on numerical model. The tidal current in the Obido channel showed northwestward flow during flood tide and southeastward flow during ebb tide with the highest water velocity of 15 cm/s, particularly, in the west mouth of the channel. Overall, the velocity of residual current in Obido channel with the highest value of 10 cm/s was higher than that between Obido and Mireukdo showing 1~3 cm/s of velocity with westward flow. Spreading and sedimentation of clay by the application of numerical model in the Obido channel was calculated under the assumption that 360 tons of clay had been introduced every day for 20 days in the area during red tide period in 2003. Clay particle spreaded toward westward in the channel and subsequently northward in the outside of the channel from the release point located in the center of the channel. It was calculated that 1.5 km2 in total nearby Obido area could be affected by the clay water with more than 1 mg/L of clay concentration within five tidal cycle after dispersion. The majority of the clay particle could be settled within 100 m from the release point with the sedimentation height of 10 mm. Also, it was calculated that the clay could show 0.2 mm of sedimentation height in the west and east mouth of Obido channel.
        4,500원
        80.
        2013.04 구독 인증기관·개인회원 무료
        Sweetpotato whitefly (Bemisia tabaci), especially Q biotype, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the conidia production of entomopathogenic fungus Isaria javanica Pf04, which had been reported high virulence isolate against Q biotype of B. tabaci, using grain. Brown rice was most suitable for conidia mass production of the isolate of I. javanica. Conidia was produced high at 25 ~ 27.5℃. The isolate produced more spores when conidia suspension directly inoculated onto media than two-phase fermentation. When concentration of inoculum was high spore production was high, but increasing rate of conidia production was highest at low inoculum concentration (1×105 conidia/ml) as 6,700 times increase compared with 20 times increase at high inoculum concentration (1×108 conidia/ml). These results indicated that the isolate can produce more conidia with cheap agricultural product and can develop as a microbial pesticide to control sweetpotato whitefly.
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