• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.827-841
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• 2019

The effect of genetically engineered rice Bt-9 on the diversity and abundance of plant-dwelling insects and spiders was tested under field conditions. Genetically engineered rice Bt-9, expressing mCry1Ac1 from Bacillus thuringiensis, confers resistance to rice leaf roller (Cnaphalocrocis medinalis) and provides tolerance to the herbicide glufosinate (PPT). The study compared Bt-9 and two non-GM reference varieties, Ilmi-byeo and Dongjin-byeo, at LMO isolated fields in Gunwi (Kyungpook National University) and Jeonju (National Institute Agricultural Sciences) in Southern Korea in 2016 - 2017. A total of 40,817 individuals from 62 families and 11 orders were collected from the two living modified organism (LMO) isolated fields. From the three types of rice fields, a total of 13,982, 14,105, and 12,730 individuals from the Bt-9, Ilmi-byeo and Dongjin-byeo were collected, respectively. Throughout the study, the analysis of variance indicated no significant differences (p < 0.05). Multivariate analysis showed that the abundance and diversity of plant dwelling insects were similar. The data on insect species population densities were subjected to principal component analysis (PCA), which did not distinguish among the three varieties, Bt-9 and the non-GM, reference cultivars, during the cultivation years. However, the results of the PCA analysis were completely divided into four groups based on the yearly survey areas. Therefore, there was no evidence for a negative impact of Bt-9 on the above-ground insects and spiders.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.511-520
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• 2022

Insect-resistant transgenic rice (Bt-T) expresses a toxic protein (mcry1Ac1) derived from the soil bacterium Bacillus thuringiensis found in the rice cultivar Dongjin with an insecticidal property against rice leaf roller (Cnaphalocrocis medinalis). In this study, to investigate the impact of Bt-T on non-target organisms, the feed and oviposition preferences and biological parameters of brown planthopper (Nilaparvata lugens Stål) were comparatively analyzed in four rice cultivars: Dongjin (parent variety), Ilmi (reference cultivar), Chinnong (brown planthopper resistant cultivar) and Bt-T. In the Bt-T and Dongjin cultivars, the feed preferences were 32.4 ± 8.3 and 34.1 ± 6.8%, and the oviposition preferences were 32.5 ± 5.1 and 30.0 ± 5.3% respectively, and there was no statistical significance between these rices. Additionally, in the Bt-T and Dongjin cultivars, the total lifespans from egg to adult were 39.5 ± 6.9 and 40.0 ± 5.8 days, and the weights of adult females were 1.78 ± 0.14 and 1.72 ± 0.16 mg, respectively. Therefore, there was no statistical difference in the biological parameters between these two varieties. Overall, the results indicate that the insect-resistant transgenic rice (Bt-T) did not negatively affect the reproduction and life cycle of brown planthopper, a non-target organism.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.385-391
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• 2006

In Korea, different kinds of genetically modified (GM) crops are under development, including GM-rice expressing insecticidal crystal (Cry) proteins of Bacillus thuringiensis (Bt) modified to change a single amino acid. In this study, amino acid (aa) sequences of modified Cry proteins were compared to that of known allergens, and Cry proteins expressed in GM-rice were identified by using Cry protein specific polyclonal antibody. The antigen-antibody reactions were compared between GM and commercial rice to assess the allergic risk of Cry proteins. This analysis showed no known allergen to have more than 35% aa sequence homology with modified Cry proteins in Bt rice over an 80 aa window or to have more than 8 consecutive identical aa. Sera from allergic patients showed some IgE reactivity via immunoblotting and enzyme-linked immunosorbent assay (ELISA), although no differences were seen between GM and commercial rice. Based on these results we conclude that GM rice with modified Cry proteins has no differences in its protein composition or allergenicity relative to commercial rice.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.296-302
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• 2011

Insect-resistant transgenic rice was developed by inserting the mCry1Ac1 a modified gene from the soil bacterium Bacillus thuringiensis (Bt). For biosafety assessment, we studied the effects on survival of cantor Daphnia magna, a commonly used as a model organism in ecotoxicological studies. D. magna fed on Bt rice and its near non-genetically modified (GM) counterparts (Nakdong) grown in the same environment (100% ground rice suspension). The Bt rice was comfirmed to have the insertion of T-DNA and protein expression by the polymerase chain reaction and ELISA analysis. Feeding study showed similar cumulative immobility and abnormal response of D. magna between Bt rice and non-GM counterparts. 48 h-$EC_{50}$ values of Bt rice and non-GM rice showed 4,429 and 2,889 mg/L respectively. The rice no observed effect concentration (NOEC) values for D. magna was suggested 1,000 mg/L. We conclude that the tested Bt-rice and Nakdong similar cumulative immobility for D. magna the widely used model organism. We found out that there is strong possibility that the growth of Bt rice didn't affect to non-target insects.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.180-189
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• 2017

Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by global agricultural companies. Until now, GM crops have not been cultivated commercially in Korea. Commercialization of GM crops requires a compulsory assessment of environmental risk associated with the release of GM crops. This study was conducted to evaluate the frequency of pollen mediated gene flow from Bt transgenic rice (Agb0101) to japonica non-GM rice (Nakdongbyeo), indica non-GM rice (IR36), and weedy rice (R55). A total of 729,917, 596,318 and 230,635 seeds were collected from Nakdongbyeo, IR36, and R55, respectively, which were planted around Agb0101. Selection of the hybrids was determined by repeated spraying of herbicide and Cry1Ac1 immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using specific primer. The hybrids were found in all non-GM rice and out-crossing ranged from 0.0005% at IR36 to 0.0027% at Nakdongbyeo. All of hybrids were located within 1.2 m distance from the Agb0101 rice plot. The meteorological elements including rainfall and temperature during rice flowering time were found to be important factors to determine rice out-crossing rate. Consideration should be taken for many factors like the meteorological elements of field and physiological condition of crop to set up the safety management guideline to prevention of GM crops gene flow.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.193-197
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• 2014

Transgenic crops that produce insecticidal toxins have a great potential for controlling target pest insects, but there is a growing concern about unintended influences on non-target species. In the present study, the preferences and performance of non-target green peach aphid, Myzus persicae (Sulzer), on transgenic cabbages (Brassica oleracea) that produce Bt toxin (Cry1Ac1) and untransformed control plants were investigated as a part of risk assessment. In a free-choice situation, the number of nymphs larviposited by 10 winged adults over 3 days was $21.9{\pm}1.8$ and $22.5{\pm}2.2$ on transgenic and the control plants, respectively, indicating that the aphids did not discriminate between the two types of plants. In a performance assay, the development time (D) and intrinsic rate of increase (rm) of wingless aphids reared on transgenic and control plants were also similar (D, $5.8{\pm}0.2$ and $5.9{\pm}0.1$ (days) and rm, $0.7{\pm}0.1$ and $0.8{\pm}0.1$, for transgenic and control plants, respectively). These results suggest that M. persicae is not significantly affected by transgenic Bt cabbage.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.355-363
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• 2022

This paper presents the modeling for islanded hybrid AC/DC microgrid and the verification of the proposed supervisory controller for energy management for this microgrid. The supervisory controller allows the microgrid system to operate in different power flows through the proposed control algorithm, it has several roles in the management of the energy flow between the different components of the microgrid for reliable operation. The proposed microgrid has both essential objectives such as the maximum use of renewable energies resources and the reduction of multiple conversion processes in an individual AC or DC microgrids. The microgrid system considered for this study has a solar photovoltaic (PV), a wind turbine (WT), a battery (BT), and a AC/DC loads. A small islanded hybrid AC/DC microgrid has been modeled and simulated using the MATLAB-Simulink. The simulation results show that the system can maintain stable operation under the proposed supervisory controller when the microgrid is switched from one operating mode of energy flow to another.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.118-119
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• 2003

Baculovirus occlusion bodies have been recently engineered to incorporate foreign protein such as the Bacillus thuringiensis (Bt) CrylAc protein for improvement of insecticidal activity. In this study, polyhedrin, cylAc, egfp and crylCa genes were fused to produce occlusion bodies that contain novel recombinant crystal protein by homologous recombination between cylAc and crylCa genes in insect cells. (omitted)

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.162-166
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• 1998

Synthetic fluid, class 7 group 2, as an insulating and cooling material is selected as. specimen, arid it is studied for the physical and electrical properties. Also, Benzotriazole(following as BT A) known as a suppressant of streaming electrification is added to it, and the change of physical and electrical properties by addition of BT A is investigated. From the spectrum of FT-IR, it is confirmed that the absorption peak in wavenumbers $3400{\sim}3450[cm^{-1}]$ is small or disappears when BTA is added. AC breakdown strength and volume resistivity of each specimen are investigated. It is considered that the effective content of BTA is about 10[ppm] for the suppression of electrification in this experiment.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.81-82
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• 2013

HVDC 시스템은 초고압 직류 송전 시스템으로써, AC를 DC로 변환하여 장거리 송전에 유리한 시스템이다. 현재 대륙간 송전 및 주파수 변환을 위한 BtB Topology에 많이 응용되고 있다. HVDC 시스템의 장점은 일정 송전거리 이상이 되면, DC가 AC에 비하여 손실율이 적고 유리한 장점이 있다. 해당 HVDC Valve는 전력을 AC-DC-AC로 변환하려면, HVDC Valve(Module)이라고 불리는 전력 변환 장치가 필수적이다. 해당 Valve를 현장에 설치하기 전에 IEC 60700-1 또는 CIGRE 같은 국제 표준 규격에 맞추어 Type Test를 진행 후에 통과 시 현장에 설치되어야 한다. 해당 Type Test는 크게 2가지로 분류되며, 절연 성능을 시험하기위한 Dielectric Test 그리고, 실제 Thyristor Valve의 동작을 가혹 한 조건에서 시험하기위한 Operational Test가 필요하다. 본 논문은 IEC 규격 (IEC 60700-1)에 의거 사이리스터 밸브에 대한 Operational Test 중 단락시험방법과 시험내용을 기술하고, 시험결과로 검증한다.