• Title/Summary/Keyword: Generation 4

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Toxicity Assessment and Establishment Acceptable Daily Intake of Penthiopyrad (펜티오피라드(Penthiopyrad)의 독성평가와 일일섭취허용량 설정)

  • Jeong, Mi-Hye;Hong, Soon-Sung;Park, Kyung-Hun;Kim, Chan-Sub;Park, Jae-Eup;Hong, Moo-Ki;Im, Moo-Hyeog;Kim, Young-Bum;Han, Bum-Seok;Han, Jeung-Sul
    • The Korean Journal of Pesticide Science
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    • v.14 no.4
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    • pp.478-489
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    • 2010
  • Penthiopyrad is a fungicide agent in types of pyrazole which is showing the effect of prevention in fungal disease and powdery mildew. In order to register this new pesticide, reports of acute toxicity and chronic toxicity by animal study were examined to set acceptable daily intake to evaluate hazards of consumers. Acute toxicity was low in toxic, and it did not have the effect of acute dermal toxicity, acute eye irritation, or skin sensitization. As the result of the study in chronic toxicity, the common effect of chemical appeared in the liver and thyroid which was proven as a toxic effect. Two-generation reproduction toxicity, genotoxicity, and prenatal development toxicity were not proven. As the result of carcinogenic study, increase of thyiroid follicular adenoma in the rat and the frequency of liver hepatocellar adenoma in mice were also increased. However, it was decided that the threshold value on the effect in chemicals could be controlled through study liver enzyme induction. Therefore, the ADI for penthiopyrad is 0.081 mg/kg/ bw/day, based on the NOAEL of 8.10 mg/kg bw/day of twelve-months dogs study and applying an uncertainty factor of 100.

Study on the Estimation of Genetic Parameters and Selection Efficiency on Early Part-record for Improving Egg Production in Layer (산난계의 유전적 모수 추정과 조기선발효율에 관한 연구)

  • 이득환;오봉국
    • Korean Journal of Poultry Science
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    • v.15 no.3
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    • pp.211-218
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    • 1988
  • Data on egg number from time of first lay to 71 week of age were obtained from samples of single comb white leghorn breeder and brown layer breeder populations which were raised at manny breeding Co. These data were used to estimate the heritabilities of age at sexual maturity, early egg number, residual egg number and annual egg number. Also, the genetic correlation coefficients between these traits were estimated and selection efficiencies of each segment in early part record were estimated by use of the heritabilities and generic correlations. The estimated heritabilities and standard errors in two lines(W and B) were $0.30\pm0.07$ and $0.33\pm0.08$ at early records, $0.19\pm0.06$ and $0.18\pm$0.05 at residual records and $0.37\pm0.09$ and $0.49\pm0.10$ at time of first lay. Those at annual records were $0.24\pm0.06$ equally. The estimated correlation coefficients and standard errors between early record and annual record were $0.76\pm0.08$ and $0.77\pm0.07$. Those between early record and residual record were $0.46\pm0.15$ and $0.39\pm0.16$ respectively. At improving annual egg production per year, selection based on early part record(SM to 40 week of age) would be 69% more efficient than on annual record in line W and 80% more efficient than on annual record in line B. But, if it were considered that egg weight decreased due to sexual maturity and cost for data collection, use of selected segment from 35~40week of age in line W and from 31~40 week of age in line B would be desired in spite of a. small loss in relative selection efficiency. The generation interval would not be shortened.

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An Empirical Analysis of the Effects of Startup' Activities of Preparatory Stage and Early Stage on Performance (창업기업의 준비 및 초기단계 활동들이 기업 성과에 미치는 영향에 관한 연구)

  • Yoon, Byeong seon;Seo, Young wook
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.11 no.4
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    • pp.1-15
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    • 2016
  • Startups in Korea are experiencing for themselves the laws of survival through competition in the local and international market, and are performing active business movements based on these. Korea's economic growth rate is 2.6% due to the slump in the domestic demand and reduced exports brought by the MERSC incident in 2015. The Korea Development Institute has estimated the economic growth rate in 2016 to be around 3.0%. South Korea's economy is facing the crisis of low-growth solidification due to the decrease in economic growth, and it is forecasted that growth without employment and polarization will worsen. Startups in the high-tech industrial generation of a particular field wherein the market environment is rapidly changing must maintain a competitive advantage with the capabilities and functions exclusive to them. It is very important that they maintain a competitive edge by utilizing the capabilities exclusive to startup companies. Likewise, the accumulation of resources is also crucial in determining the success of a startup business. In a poor local startup ecosystem, majority of the startup companies are performing their business activities while striving for survival, rather than success. About 80% are struggling to survive and are failing to overcome the "Death Valley" faced 3-5 years after establishing the company. Since majority of the startups fail to achieve results during the initial stages of foundation, the importance of research on business activities and achievement during the early stages of establishment is being raised. In accordance to this, this research has performed an actual analysis on how the activities of startups during their preparation phase and early stages affect their achievements. A survey was done on the CEOs or executives (people in a position to make decisions) of local small and medium-sized enterprises that are considered start-ups, and 203 valid data were collected and analyzed. Results showed that the discoveries and utilized activities necessary for the businesses of startups have a significant impact on their achievement through the entrepreneur resources and external partners' cooperation; additionally, the related implications were discussed.

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Photoimmunology -Past, Present and Future-

  • Daynes, Raymond A.;Chung, Hun-Taeg;Roberts, Lee K.
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.3
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    • pp.311-329
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    • 1986
  • The experimental exposure of animals to sources of ultraviolet radiation (UVR) which emit their energy primarily in the UVB region (280-320nm) is known to result in a number of well-described changes in the recipient's immune competence. Two such changes include a depressed capacity to effectively respond immunologically to transplants of syngeneic UVR tumors and a markedly reduced responsiveness to known inducers of delayedtype (DTH) and contact hypersensitivity (CH) reactions. The results of experiments that were designed to elucidate the mechanisms responsible for UVR-induced immunomodulation have implicated: 1) an altered pattern of lymphocyte recirculation, 2) suppressor T cells(Ts), 3) deviations in systemic antigen presenting cell (APC) potential. 4) changes in the production of interleukin-1-like molecules, and 5) the functional inactivation of epidermal Langerhans cells in this process. The exposure of skin to UVR, therefore, causes a number of both local and systemic alterations to the normal host immune system. In spite of this seeming complexity and diversity of responses, our recent studies have established that each of the UVR-mediated changes is probably of equal importance to creating the UVR-induced immunocompromised state. Normal animals were exposed to low dose UVR radiation on their dorsal surfaces under conditions where a $3.0\;cm^2$ area of skin was physically protected from the light energy. Contact sensitization of these animals with DNFB, to either the irradiated or protected back skin, resulted in markedly reduced CH responses. This was observed in spite of a normal responsiveness following the skin sensitization to ventral surfaces of the UVR-exposed animals. Systemic treatment of the low dose UVR recipients with the drug indomethacin (1-3 micrograms/day) during the UVR exposures resulted in a complete reversal of the depressions observed following DNFB sensitization to "protected" dorsal skin while the altered responsiveness found in the group exposed to the skin reactive chemical through directly UVR-exposed sites was maintained. These studies implicate the importance of EC as effective APC in the skin and also suggest that some of the systemic influences caused by UVR exposure involve the production of prostaglandins. This concept was further supported by finding that indomethacin treatment was also capable of totally reversing the systemic depressions in CH responsiveness caused by high dose UVR exposure (30K joules/$m^2$) of mice. Attempts to analyze the cellular mechanisms responsible established that the spleens of all animals which demonstrated altered CH responses, regardless of whether sensitization was through a normal or an irradiated skin site, contained suppressor cells. Interestingly, we also found normal levels of T effector cells in the peripheral lymph nodes of the UVR-exposed mice that were contact sensitized through normal skin. No effector cells were found when skin sensitization took place through irradiated skin sites. In spite of such an apparent paradox, insight into the probable mechanisms responsible for these observations was provided by establishing that UVR exposure of skin results in a striking and dose-dependent blockade of the efferent lymphatic vessels in all peripheral lymph nodes. Therefore, the afferent phases of immune responses can apparently take place normally in UVR exposed animals when antigen is applied to normal skin. The final effector responses, however, appear to be inhibited in the UVR-exposed animals by an apparent block of effector cell mobility. This contrasts with findings in the normal animals. Following contact sensitization, normal animals were also found to simultaneously contain both antigen specific suppressor T cells and lymph node effector cells. However, these normal animals were fully capable of mobilizing their effector cells into the systemic circulation, thereby allowing a localization of these cells to peripheral sites of antigen challenge. Our results suggest that UVR is probably not a significant inducer of suppressor T-cell activity to topically applied antigens. Rather, UVR exposure appears to modify the normal relationship which exists between effector and regulatory immune responses in vivo. It does so by either causing a direct reduction in the skin's APC function, a situation which results in an absence of effector cell generation to antigens applied to UVR-exposed skin sites, inhibiting the capacity of effector cells to gain access to skin sites of antigen challenge or by sequestering the lymphocytes with effector cell potential into the draining peripheral lymph nodes. Each of these situations result in a similar effect on the UVR-exposed host, that being a reduced capacity to elicit a CH response. We hypothesize that altered DTH responses, altered alloresponses, and altered graft-versus-host responses, all of which have been observed in UVR exposed animals, may result from similar mechanisms.

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Prevalence and Risk Factors of Vancomycin-Resistant Enterococci (VRE) Colonization in Neonates (신생아에서 Vancomycin 내성 장구균의 감시 및 위험인자 분석)

  • Lee, Hwa Yun;Kim, Gi Hwan;Choi, Jin Su;Kim, Sun Hee;Choi, Young Youn;Hwang, Tai Ju
    • Clinical and Experimental Pediatrics
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    • v.48 no.9
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    • pp.946-952
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    • 2005
  • Purpose : Vancomycin-resistant enterococci(VRE) are now nosocomial pathogens in Korea. But little is known about the prevalence of stool colonization with VRE in neonates in Korea. So we studied the prevalence and risk factors of VRE colonization in the Neonatal Intensive Care Unit(NICU). Methods : From January 2000 to December 2004, the medical records of 294 neonates(127 cases of VRE group and 167 cases of non-VRE group, according to the results of stool culture) were reviewed retrospectively. We studied the annual prevalence of VRE and risk factors of VRE colonization in neonates. Results : From 2000 to 2003, the prevalence rate of VRE in NICU increased. After preventing VRE transmission, the prevalence rate of VRE has decreased. Conclusion : VRE colonization increased recently. Risk factors of VRE colonization were prematurity, lower birth weight, longer hospitalization and use of vancomycin or 3rd generation cephalosporin, compared with the non-VRE group. To prevent VRE transmission among newborns, aggressive infection control strategies by NICU staffs must be implemented immediately for all babies.

Reduction of Carbon-Dioxide Emission Applying Carbon Capture and Storage(CCS) Technology to Power Generation and Industry Sectors in Korea (국내 전력 발전 및 산업 부문에서 탄소 포집 및 저장(CCS) 기술을 이용한 이산화탄소 배출 저감)

  • Wee, Jung-Ho;Kim, Jeong-In;Song, In-Sung;Song, Bo-Yun;Choi, Kyoung-Sik
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.9
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    • pp.961-972
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    • 2008
  • In 2004, total emissions of Greenhouse Gases(GHGs) in Korea was estimated to be about 590 million metric tons, which is the world's 10th largest emissions. Considering the much amount of nation's GHG emissions and growing nation's position in the world, GHG emissions in Korea should be reduced in near future. The CO$_2$ emissions from two sub-sections of energy sector in Korea, such as thermal power plant and industry section(including manufacturing and construction industries), was about 300 million metric tons in 2004 and this is 53.3% of total GHG emissions in Korea. So, the mitigation of CO$_2$ emissions in these two section is more important and more effective to reduce the nation's total GHGs than any other fields. In addition, these two section have high potential to qualitatively and effectively apply the CCS(Carbon Capture and Storage) technologies due to the nature of their process. There are several CCS technologies applied to these two section. In short term, the chemical absorption technology using amine as a absorbent could be the most effectively used. In middle or long term, pre-combustion technology equipped with ATR(Autothermal reforming), or MSR-$H_2$(Methane steam reformer with hydrogen separation membrane reactor) unit and oxyfuel combustion such as SOFC+GT(Solid oxide fuel cell-Gas turbine) process would be the promising technologies to reduce the CO$_2$ emissions in two areas. It is expected that these advanced CCS technologies can reduce the CO$_2$ avoidance cost to $US 8.5-43.5/tCO$_2$. Using the CCS technologies, if the CO$_2$ emissions from two sub-sections of energy sector could be reduced to even 10% of total emissions, the amount of 30 million metric tons of CO$_2$ could be mitigated.

Study on Tiangui(天癸)Focusing on the ${\ulcorner}$Neijing${\lrcorner}$(內經) commentators' views (천계(天癸)에 대한 연구 -내경(內經) 주석가(注釋家)들의 견해(見解)를 중심으로-)

  • Lee, Yong-Beom;Heo, Gi-Hoe
    • Journal of Korean Medical classics
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    • v.13 no.2 s.17
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    • pp.174-188
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    • 2000
  • The meaning of Tiangui(天癸) in $Suwen{\cdot}Shanggutianzhenlun\;素問{\cdot}上古天眞論$ is very important because it has the cause of 'having a child' and it shows the signs to being healthy. But until now there have been many arguments about what the correct meaning of Tiangui is. The most important thing in these arguments is to compare and analyze Neijing(內經) commentators' views, and to understand differences between their views. So I compared and analyzed by focusing on Neijing(內經) text, the other books with explanatory notes, and other commentators' views, and, after that. I got the following results. 1. On the meaning of Tian(天), Wangbing(王氷) and Mashi(馬蒔) considered that it is inborn. Zhangjiecong(張志聽) considered it as the Yang(陽) producing Yin(陰) Zhangjiebin(張介賓) regarded it as the Yang(陽) of Gua symbol. On the meaning of the Gui(癸). Zhangjiebin(張介賓) said that it is Yin qi(陰氣) which is the prior step to Xing(形). Mashi(馬蒔) and Zhangzhicong(張志聽) said that it is spirit or Jingxue(spiritual sanguine) which is the concrete constituents in our body. 2. On the relation bet ween Tian(天) and Gui(癸), Mashi(馬蒔) and Zhangzhicong(張志聽) said that Gui(癸) is made from Tian(天), and Zhangjiebin(張介賓) said that Tian is intrinsic in Gui(癸). 3. On the relation between Tiangui(天癸) and Jingxue(精血), Yangshangshan(楊上善). Wangbing(王氷), and Zhangjiebin(張介賓) regarded Tiangui(天癸) as a concrete matter which is the prior step to becoming Jingxue(精血). Mashi(馬蒔) and Zhangjiecong(張志聽) considered Tiangui(天癸) as a concrete matter. Mashi(馬蒔) considered Tiangui(天癸) as Jing(精)which is directly related to pregnancy. Zhangjiecong(張志聽) regarded Tiangui(天癸) as Jingxue(精血) which controls general physiology of men and women. 4. On the function of Tiangui(天癸), Yangshangshan(楊上善) and Wangbing(王氷) considered that Tiangui (天癸) has relation to menstruation. pregnancy. and, production and extinction of Jing(精). Zhangjiecong(張志聽) argued that Tiangui(天癸) strengthens and warms muscle and derma. and controls differential physiology between men and women, and said that the maintenance of its activity is based on the acquired spirit of food. A book of 『Huangti Neijing Yanjiu Dacheng(黃帝內經硏究大成)』 said that the function of Tiangui(天癸) is to promote generation, to develop the second sexual symbol, and to make growing and aging in body. It also said that Tiangui(天癸) has some relation to kidney and other organs, Chong Meridian, Ren Meridian, Du Meridian, and Dai Meridian. 5. Other commentators of 『Neijing(內經)』 accepted the meaning of Tiangui(天癸) as the prior step of both man's spiritual overflowing and woman's menstruation. 6. On the relation between Tiangui(天癸). and, Cheng and Ren Meridians, Yangshangshan(楊上善) and Zhangjiecong(張志聽) said that Tiangui(天癸) has direct relation with two meridians. Wangbing(王氷) said that Tiangui(天癸) and two meridians have no direct relation. Now I compared commentaors' views of Tiangui(天癸) and studied the differences between their views. I concluded that on the concept of Tiangui(天癸), Zhangjiebin(張介賓)'s explanations express well its connotative meaning. And on the function of Tiangui (天癸), Zhangjiecong(張志聽)'s explanations are excellent because he organized well his seniors' views, and extended its meaning by showing Neijing(內經)'s phrases related to Chong and Ren Meridians. Also, Mashi(馬蒔) suggested that if Tiangui(天癸) comes earlier than normal. people will die soon. But I think that more studies on male and female bodies are needed as to Mashi(馬蒔)'s argument.

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Development of nutrition quotient for Korean preschoolers (NQ-P): Item selection and validation of factor structure (취학전아동 대상 영양지수 개발 : 평가항목 선정과 구성 타당도 검증)

  • Lee, Jung-Sug;Kang, Myung-Hee;Kwak, Tong-Kyung;Chung, Hae Rang;Kwon, Sehyug;Kim, Hye-Young;Hwang, Ji-Yun;Choi, Young-Sun
    • Journal of Nutrition and Health
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    • v.49 no.5
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    • pp.378-394
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    • 2016
  • Purpose: Screening of preschool-age children for nutrition programs to improve dietary intake and behaviors requires cost-effective and easily administered validated assessment tools. The purpose of this study was to develop a parent/caregiver-administered instrument for measuring diet quality and behaviors of preschoolers as a nutrition quotient for preschoolers (NQ-P). Methods: Development of NQ-P was carried out in three steps: item generation, item reduction, and validation. The 24-h dietary record was selected as the gold standard reference tool. The 38 items of the NQ-P checklist were derived from a systematic literature review, expert in-depth interviews, statistical analysis of the fifth Korean National Health and Nutrition Examination Survey data, and national nutrition policies and recommendations. Self-administered questionnaires were delivered to parents who recorded 24-h dietary intakes of 100 responders aged 3~5 yr. Pearson's correlation was used to measure the level of agreement between questionnaires. Item reduction was performed, and 20 items were selected based on survey results, expert reviews, and priorities of national nutrition policy and recommendations. The 412 nationwide subjects sampled through daycare centers completed the 20-item checklist questionnaire. The construct validity of the NQ-P was assessed using confirmatory factor analysis, LISREL. Results: After analyses of exploratory factors, NQ-P items identified three dimensions of diet (balance, moderation, and environment). The three-factor structure accounted for 49.28% of the total variance. Standardized path coefficients were used as weights of the items. The NQ-P and three-factor scores of the subjects were calculated by the obtained weights of the questionnaire items. Conclusion: A food behavior checklist for preschoolers' NQ would be a useful and suitable instrument for evaluating nutrition adequacy and dietary quality of Korean preschoolers.

A Proposal for Promotion of Research Activities by Analysis of KOSEF's Basic Research Supports in Agricultural Sciences (한국과학재단의 농수산분야 기초연구지원 추이분석을 통한 연구활동지원 활성화 제언)

  • Min, Tae-Sun;Choi, Hyung-Kyoon;Kim, Seong-Yong;Bai, Sung-Chul;Kim, Yoo-Yong;Yang, Moon-Sik;Chung, Bong-Hyun;Hwang, Joon-Young;Han, In-Kyu
    • Applied Biological Chemistry
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    • v.48 no.1
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    • pp.23-33
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    • 2005
  • Agricultural sciences field in South Korea has many strong points such as numerous researchers, establishment of research infra-structure, excellence in research competitiveness and high technological level. However, there are also many weaknesses including insufficient leadership at related societies and institutes, deficiency of the next generation research group, and insufficiency in research productivity. There are many opportunities including increasing the importance of the biotechnological industry, activating international cooperation researches, and exploring the multitude of possible research areas to be studied. However, some threats still exist, such as pressure from the government of developed countries to open the agricultural market, the decrease of specialized farms, and intensification for researches to gratify economic and social demands. To encourage research activities in the agricultural sciences field in Korea, the following actions and systems are required: 1) formulation of a mid- and a long-term research master plan, 2) development of a database on the man power in related fields, 3) activation of top-down research topics, and associated increase of individual research grants, 4) development of special national programs for basic researches in agricultural sciences, 5) organization of a committee for policy and planning within the related societies, and 6) system development for the fair evaluation of the research results.

Characteristics of Resistance to Chlorpyrifos in Diamondback-moth (Plutella xylostella L.) (Chlorpyrifos 저항성 배추좀나방(Plutella xylostella L.)의 살충제 저항성 특성)

  • Kim, Kyung-Ju;Kim, Sung-Su;Kim, Song-Mun;Hur, Jang-Hyun
    • The Korean Journal of Pesticide Science
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    • v.7 no.4
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    • pp.288-295
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    • 2003
  • To determine the mechanism of the resistance to organophosphorus insecticide, chlorpyrifos, in diamondback-moth (Plutella xylostella L.), activities of esterases, glutathione-S-transferase (GST) and AChE insensitivity which were known for causing factor of resistance were measured. Also, the relationship between AChE insensitivity and the resistant ratio was investigated to inquiry the cross-resistance. The resistant ratio of chlorpyrifos-resistant strain (CRS) of diamondback-moth at the 6th generation was developed 160 fold compared to susceptible strain (SS) one. Activity of GST that are extracted from CRS was 1.7-fold higher than that from SS. However, activity of total esterases from CRS was similar to that from SS. In AChE insensitivity test, CRS was 11.8-fold less sensitive than that from SS. CRS was ranged from 17.6 to 33.6-fold less sensitive than SS to other insecticides having same target site with chlorpyrifos such as dichlorvos, dimethylvinphos and carbofuran. Insensitivity of AChE to phenthoate-oxon, however, was 1.7-fold. Resistance of CRS was 82-fold, 47-fold and 42-fold higher than SS to dichlorvos, dimethylvinphos and carbofuran, respectively, but 2.3-fold to phenthoate and then we could identify that the resistance development of insecticide might have a lot of difference among the chemicals with the same target site. The relationship between the AChE insensitivity and the resistant ratio was significantly correlated$(r=0.9951^{**},\;p^{(0.01)}$. This result indicates that AChE insensitivity was associated with insecticide resistance. Overall, these results suggest that insensitivity of AChE was an important factors to chlorpyrifos resistance in diamondback-moth, and the slightly increased activity of GST may also have contributed to that.