• Title/Summary/Keyword: CO3

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Landscape Analysis of the Hallasan National Park in a Jeju Island Biosphere Reserve: Fragmentation Pattern (제주 생물권보전지역 내 한라산국립공원의 경관분석 : 단편화 현상)

  • Kang, Hye-Soon;Kim, Hyun-Jung;Chang, Eun-Mi
    • Korean Journal of Environment and Ecology
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    • v.22 no.3
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    • pp.309-319
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    • 2008
  • Roads are an indicator of anthropogenic activity causing ecosystem disturbances and often lead to habitat fragmentation, habitat loss, and habitat isolation. The Hallasan National Park(153.4$km^2$) on Jeju Island being distinguished for its unique geology, topography, and biota has also been designated as a core area of UNESCO Man and the Biosphere(MAB) Reserve. Although the high conservation value of this park has contributed to a rapid growth of tourists and road construction, landscape changes due to roads have not been examined yet. We used GIS systems to examine the fragmentation pattern caused by roads, in relation to its zonation, elevation, and vegetation. When a buffer was applied to roads(112m width for paved roads and 60m width for both legal and illegal trails), the park consisted of 100 fragments. The ten fragments generated after applying buffer to only paved roads and legal trails ranged from $0.002km^2$ to $38.2km^2$ with a mean of $14.2km^2$, and about 7% of both nature conservation zone and nature environment zone of the park were edge. Fragments in both east and west ends of the park and around the summit exhibited relatively high shape indices with means of 5.19(for 100 fragments) and 7.22(for 10 fragments). All five legal trails are connected to the pit crater of the mountain and vegetation changed from broadleaf forests and conifer forests to grasslands with elevation, consequently resulting in dramatic fragment size reduction in grasslands at high elevation, in particular above 1,400m, where endemic and alpine plants are abundant. These results show that in Hallasan National Park the risks of habitat deterioration and habitat loss due to fragmentation may be more severe in the nature conservation zone dominated by Baengnokdam than in the nature environment zone. Therefore, current road networks of the park appear to fall short of the goal of the national park for ecosystem conservation and protection. Considering that the entire Hallasan National Park also serves as a MAB core area, conservation efforts should focus, first of all, on park rezoning and road management to mitigate habitat fragmentation.

Evaluation of the Minimum Shear Reinforcement Ratio of Reinforced Concrete Members (철근콘크리트 부재의 최소전단보강근비의 평가)

  • Lee Jung-Yoon;Yoon Sung-Hyun
    • Journal of the Korea Concrete Institute
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    • v.16 no.1 s.79
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    • pp.43-53
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    • 2004
  • The current Korean Concrete Design Code(KCI Code) requires the minimum and maximum content of shear s in order to prevent brittle and noneconomic design. However, the required content of the steel reinforcement In KCI Code is quite different to those of the other design codes such as fib-code, Canadian Code, and Japanese Code. Furthermore, since the evaluation equations of the minimum and maximum shear reinforcement for the current KCI Code were based on the experimental results, the equations can not be used for the RC members beyond the experimental application limits. The concrete tensile strength, shear stress, crack inclination, strain perpendicular to the crack, and shear span ratio are strongly related to the lower and upper limits of shear reinforcement. In this research, an evaluation equation for the minimum content of shear reinforcement is theoretical proposed from the Wavier's three principals of the mechanics of materials.

A Study on Laboratory Treatment of Metalworking Wastewater Using Ultrafiltration Membrane System and Its Field Application (한외여과막시스템을 이용한 금속가공폐수의 실험실적 처리 및 현장 적용 연구)

  • Bae, Jae Heum;Hwang, In-Gook;Jeon, Sung Duk
    • Korean Chemical Engineering Research
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    • v.43 no.4
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    • pp.487-494
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    • 2005
  • Nowadays a large amount of wastewater containing metal working fluids and cleaning agents is generated during the cleaning process of parts working in various industries of automobile, machine and metal, and electronics etc. In this study, aqueous or semi-aqueous cleaning wastewater contaminated with soluble or nonsoluble oils was treated using ultrafiltration system. And the membrane permeability flux and performance of oil-water separation (or COD removal efficiency) of the ultrafiltration system employing PAN as its membrane material were measured at various operating conditions with change of membrane pore sizes and soil concentrations of wastewater and examined their suitability for wastewater treatment contaminated with soluble or insoluble oil. As a result, in case of wastewater contaminated with soluble oil and aqueous or semi-aqueous cleaning agent, the membrane permeability increased rapidly even though COD removal efficiency was almost constant as 90 or 95% as the membrane pore size increased from 10 kDa to 100 kDa. However, in case of the wastewater contaminated with nonsoluble oil and aqueous or semi-aqueous cleaning agent, as the membrane pore size increased from 10 kDa to 100 kDa and the soil concentration of wastewater increased, the membrane permeability was reduced rapidly while COD removal efficiency was almost constant. These phenomena explain that since the membrane material is hydrophilic PAN material, it blocks nonsoluble oil and reduces membrane permeability. Thus, it can be concluded that the aqueous or semi-aqueous cleaning solution contaminated with soluble oil can be treated by ultrafiltration system with the membrane of PAN material and its pore size of 100 kDa. Based on these basic experimental results, a pilot plant facility of ultrafiltration system with PAN material and 100 kDa pore size was designed, installed and operated in order to treat and recycle alkaline cleaning solution contaminated with deep drawing oil. As a result of its field application, the ultrafiltration system was able to separate aqueous cleaning solution and soluble oil effectively, and recycle them. Further more, it can increase life span of aqueous cleaning solution 12 times compared with the previous process.

A survey on the EMF Levels of Study and Electric Appliances in Korea (국내 전철 및 가전제품을 대상으로 한 전자장 수준 실태조사)

  • Jang, Seong Ki;Cho, Yong Sung;Lee, Seok Jo;Yoo, Seong Wha;Jung, Kyung Mi;Lim, Jun Ho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.15 no.1
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    • pp.71-81
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    • 2005
  • The purposes of this study was to collect, analyze, and describe the MF exposure levels from subways in Korea and to measure and evaluate the MF levels generated from electric appliances used at general homes. The target subway lines were Seoul Metropolitan Line 1 to Line 8, Bundang Line, Incheon Line, Daegu Line, Gwangju Line, and Busan Line 1 and Line 2. We measured at each station in those subway lines and, all the train types (pantograph-equipped, motor-equipped, and common), and platform types(facing and isolating) were investigated by the distance(80, 200, 400 cm) from the train on 19 targeted subway lines using 3 magnetic field measuring devices (EMDEXII, Enertech Co.) during the survey from January till October, 2004. On the other hand, the levels of the 60Hz magnetic fields generated from 14 items of home electric appliances such as electric blankets, hair dryers, electric razors, etc. were measured at 10 general homes using 5 EMDEXII meters with a sampling interval of 1.5 second by the distance(surface, 30, 50, 100, 300cm ) from the target electric appliances. The survey results in the whole subway lines examined in this study were as follows; Seoul Metropolitan Line 4 using AC(alternating current) power source showed the highest mean value of $2.85{\mu}T$, followed by Seoul Metropolitan Line 1 running between Seoul and Incheon using AC($2.78{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Uijongbu using AC($2.73{\mu}T$), Bundang Line using AC($1.79{\mu}T$), Seoul Metropolitan Line 1 connected from Yongsan using AC($1.67{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Suwon using AC($0.79{\mu}T$), and so on. In general, the intensity of the magnetic field in the subway systems in Korea was significantly higher when using AC($2.14{\pm}0.91{\mu}T$) than when using DC($0.29{\pm}0.44{\mu}T$) power source. Among the home electric appliances examined, microwave ovens showed the highest mean value of $7.69{\mu}T$, followed by hair dryers($6.47{\mu}T$), vacuum cleaners($5.27{\mu}T$), televisions ($2.26{\mu}T$), electric blankets($1.38{\mu}T$), personal computers ($0.81{\mu}T$), and so on. Two items of electric appliances showed the excess value of $0.2{\mu}T$ at the distance of 30cm in the MF exposure level; electric razors $1.58{\pm}2.13{\mu}T$ and vacuum cleaners $0.48{\pm}0.44{\mu}T$. As a whole, this study showed a tendency that the shift of the MF levels according to the increase of distance from the electric appliances was lower than those of the results surveyed in UK and USA. As a result, this study is expected to suggest meaningful data for the future study in exposure assessment of magnetic fields and for the establishment of guidelines for subways and electric appliances in Korea. More detailed and large scaled exposure assessment studies should be performed continuously to get the various and useful information on health risk assessment of MFs in Korea.

The Effect of Taipet-F and Bactokil on Retarding Lipid Oxidation in Boiled-dried Anchovy (Taipet-F와 Bactokil처리가 마른멸치의 산패방지에 미치는 효과)

  • Lee, Eung-Ho;Kim, Jin-Soo;Ahn, Chang-Bum;Park, Hee-Yeol;Jee, Seung-Kil;Joo, Dong-Sik;Lee, Seung-Won;Lim, Chi-Won;Kim, Il-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.18 no.2
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    • pp.181-188
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    • 1989
  • The present study has been carried out to investigate the effect of Bactokil(made from didecyldimethyl ammonium chloride isopropanol and water) and Taipet-F (made from natural vitamin E, L-ascorbic acid, glyceride and gallic acid) on retarding lipid oxidation in boiled-dried anchovy. To process boiled-dried anchovy, boiled anchovy dried in cabinet drier $(dry-bulb\;temperature\;40^{\circ}C)$ for 1 hour were fronted with the Bactokil, the Taipet-F and mixture of Bactokil and Taipet-F, respectively. Anchovy fronted with chemicals were redried for 8 hours, packed in polyethylene film bag, and then stored at room temperature $(24{\pm}3^{\circ}C)$. These products were compared with control(untreated with chemicals) during storage. The changes in volatile basic nitrogen of each product was negligible during storage. The thiobarbituric acid and peroxide values of each product increased up to 10 days of storage, and then decreased. In color value of each product, L value increased, while n, b and ${\bigtriangleup}E$ values decreased during storage. The changes in brown pigment formation of each product increased up to final stage of storage. From the results of chemical analysis and sensory evaluation, the product treated with Taipet-F(0.5%, v/v) was the most effective on retarding lipid oxidation of the boiled -dried anchovy, followed by the product treated withthe mixture of Bactokil (0.04%, v/v) and Taipet-F (0.5%, v/v), the product treated with Bactokil(0.04%, v/v) and control, in the order named.

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Organizational Factors Facilitating the Internationalization of Korean Franchising Companies (해외진출 국내 프랜차이즈기업의 조직특성)

  • Lim, Young-Kun;Lee, Dong-Whuy;Kim, Hee-Jung
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.2
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    • pp.40-52
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    • 2009
  • Franchising is one of the fastest growing types of business. It is already popular and well-known in the U.S., and has been growing in many other countries including Korea. Furthermore, many Korean franchising companies have expanded their business overseas actively. According to the data by the Ministry of Industry and Resource, 82 companies out of a sample of 500 franchising companies are already operating in many foreign countries and 48% of them have started their foreign business since 2006. This clearly indicates the fast growing current trend of foreign operation by Korean franchising companies. In spite of the fast growing trend of foreign expansion in the industry, academic research on internationalization of franchising companies is extremely difficult to find. Accordingly, academic research on the issue is necessary and urgent in Korea. Among the various research questions on internationalization of franchising business, this study intends to investigate the difference in organizational factors between the franchising companies doing foreign operation and those doing business only domestically. More specifically, this research has the following purposes. First, considering the lack of theoretical basis of previous studies, resource-based theory and agency theory are employed as the theoretical bases. Second, this study explains the difference in internationalization based on organizational factors such as company size, history and growth rate. Third, the five hypotheses regarding the difference in organizational factors are presented and tested empirically, which is the first attempt in the area of this topic. Finally, the study attempts to clarify the conflicting implications among theories regarding some organizational factos such as growth rate. As the theoretical background, resource-based theory and agency theory are discussed. According to resource-based theory, a firm can grow continuously when it has competence and resource, and also the ability to develop them. The competence and resource can include capital, human resource, management skill, market information, ability to manage risk, etc. Meanwhile, agency theory views the relationship between franchisor and franchisee as an agency relationship. In agency theory, bonding capability and monitoring capability are the two key factors which promote internationalization of franchising companies. Based on the two theories, a conceptual model is designed. The model consists of two groups of variables. One is organizational factors including size, history, growth rate, price bonding and geographic dispersion. The other is whether a franchising company is operating overseas or not. We developed the following five research hypotheses basically describing the relationship between organizational factors and internationalization of franchising companies. H1: The size of franchising companies operating overseas is larger than that of franchising companies operating domestically. H2: The history of franchising companies operating overseas is longer than that of franchising companies operating domestically. H3: The growth rate of franchising companies operating overseas is higher than that of franchising companies operating domestically. H4: The price bonding of franchising companies operating overseas is higher than that of franchising companies operating domestically. H5: The geographic dispersion of franchising companies operating overseas is wider than that of franchising companies operating domestically. Data for the analyses are obtained from 2005 Korea Franchise Survey data co-generated by Ministry of Industry and Resource, GS1 Korea, and Korea Franchise Association. Out of 2,804 population companies, 2,489 companies are excluded for various reasons and 315 companies are selected as the final sample. Prior to hypotheses tests, validity and reliability of the measures of size, history, growth rate and price bonding are examined for further analyses. Geographic dispersion is not validated since it is measured using nominal data. A series of independent sample T-tests is used to find out whether there exists any significant difference between the companies internationalized and those operating only domestically for each organizational factor. Among the five factors, size and geographic dispersion show significant difference, growth rate and price bonding do not reveal any difference and, finally, history factor shows conflicting results in the difference depending on how to measure it.

    shows the summary statistics for hypotheses testing. In conclusion, the results show that the size and history, which are the key variables in resource-based theory, have a significant relationship with internationalization and that geographic area, which belongs to agency theory, also has a strong relationship with internationalization. The results support the findings of extant research and, therefore, prove the usefulness of resource-based theory and agency theory in explaining internationalization of franchising companies. However, growth rate and price-bonding do not show a clear difference between the two types of companies. Accordingly, these two factors need further attention in the future research. Although this study shows meaningful findings theoretically and practically, it has several limitations. First, only organizational factors are considered even if there are various environmental factors influencing franchising firm's internationalization. Second, only being internationalized or not is considered. That is, modes of entry and the size of foreign operations are not included in the study. Third, internationalization strategy is often determined based on the desire for business expansion and higher profitability and egoistical reasons of the CEOs. However, this type of factors belonging to behavioral science is not discussed in the study. Finally, organizational ecology perspective is usefully applicable in explaining the survival and performance of internationally operating companies. Accordingly, research propositions based on this perspective need to be developed and tested.

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  • Particulate Matter Removal of Indoor Plants, Dieffenbachia amoena 'Marianne' and Spathiphyllum spp. according to Light Intensity (광량에 따른 실내식물 디펜바키아와 스파티필럼의 미세먼지 제거능)

    • Kwon, Kei-Jung;Park, Bong-Ju
      • Journal of the Korean Institute of Landscape Architecture
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      • v.46 no.2
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      • pp.62-68
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      • 2018
    • This study investigated the effect of light intensity on the removal of particulate matter by Dieffenbachia amoena 'Marianne' and Spathiphyllum spp.. An acrylic chamber ($600{\times}800{\times}1200mm$, $L{\times}W{\times}H$) modeled as an indoor space and a green bio-filter ($495{\times}495{\times}1000mm$, $L{\times}W{\times}H$) as an air purification device were made of acrylic. The removal of particulate matter PM10 and PM1, the photosynthetic rate, stomatal conductance, and number of stomata of Dieffenbachia amoena 'Marianne' and Spathiphyllum spp. were measured according to three different levels of light intensity (0, 30 and $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$). Regarding the length of time taken for PM10 to reach $1{\mu}g$, the Dieffenbachia amoena 'Marianne' showed a significant difference according to the presence or absence of light, and there was no significant difference shown between light intensity of 30 and $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. As for the Spathiphyllum spp., there was no significant difference between 0 and $30{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$, while a significant difference was shown at $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. After 90 minutes, the PM1, PM10, and $CO_2$ residuals of the Spathiphyllum spp. were lowest at $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. The remaining amount of PM1 and PM10 was lower with the Spathiphyllum spp. than with the Dieffenbachia amoena 'Marianne', even at $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. With both plants, the higher the light intensity, the higher the photosynthetic rate, while the stomatal conductance did not show any significant difference. Spathiphyllum spp. showed a higher photosynthetic rate and stomatal conductance and a greater number of stomata than Dieffenbachia amoena 'Marianne', and stomata were observed in both the front and back sides of the leaves. The air purification effect of Spathiphyllum spp. is considered to be better than Dieffenbachia amoena 'Marianne' at the same light intensity due to such plant characteristics. Therefore, in order to select effective indoor plants for the removal of particulate contamination in an indoor space, the characteristics of plants such as the photosynthetic rate and the number and arrangement of stomata according to indoor light intensity should be considered.

    Shear Strength Evaluation on Multiple High-Shear Ring Anchors Using Shear Strength Model of a Single High-Shear Ring Anchor (단일 고전단 링앵커의 전단강도 모델을 이용한 다수 고전단 링앵커의 전단강도 평가)

    • Kim, Mun-Gil;Chun, Sung-Chul;Kim, Young-Ho;Sim, Hye-Jung;Bae, Min-Seo
      • Journal of the Korea Concrete Institute
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      • v.28 no.4
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      • pp.463-471
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      • 2016
    • A shear strength model for the high-shear ring anchor consisting of a steel ring and a rod was developed based on the shear tests on single high-shear ring anchors. The shear strength was found to be proportional to $f_{ck}{^{0.75}}$ which is a similar characteristic to the strength of shear connectors used in composite structures. The effects of the compressive strength of concrete, edge distance, and embedment length of rod are included in the proposed model. Comparison with 22 tests shows that the average and the coefficient of variation of test-to-prediction ratios are 1.01 and 7.57%, respectively. Push tests on the specimens having four high-shear ring anchors at each face were conducted and the measured shear strengths were compared with the predictions by the proposed model. For the specimen with an edge distance of 100 mm, a splitting failure occurred and for the specimens with an edge distance of 150 mm, a failure mode mixed with splitting and bearing occurred, which were very similar to the failures of shear tests on single high-shear ring anchors. In case of a splitting failure, the overlap of failure surfaces could be prevented by providing the longitudinal spacing of 400 mm which is four times of the edge distance. In case of a bearing failure, the failure area is less than 150 mm from the center of the anchor and therefore the overlap of failure surfaces could be prevented by providing the longitudinal spacing of 200 mm. The average of the test-to-prediction ratios of Push tests is 98%, which means that the proposed mode can be applied to predict the shear strength of the multiple high-shear rings.

    Evaluation of Long-term Data Obtained from Seawater Intrusion Monitoring Network using Variation Type Analysis (변동유형 분석법을 이용한 해수침투 관측망 자료 평가)

    • Song, Sung-Ho;Lee, Jin-Yong;Yi, Myeong-Jae
      • Journal of the Korean earth science society
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      • v.28 no.4
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      • pp.478-490
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      • 2007
    • With groundwater data of seawater intrusion monitoring network in coastal areas of Korea's main land, we analyzed types of seawater intrusion through the coastal aquifer. The data including groundwater level, temperature and electrical conductivity obtained from 45 monitoring wells at 25 watershed regions were evaluated. Based on statistical analysis, correlation analysis and variation type analysis, groundwater levels were mainly affected by rainfall and artificial pumping. About 78% of the monitoring wells showed average temperature higher than $15^{\circ}C$ and about 58% of them showed minimum variations less than $0.2^{\circ}C$. Electrical conductivities showed a large magnitude of variation and irregular characteristics compared with groundwater levels and temperatures. Average electrical conductivities lower than $2,000\;{\mu}S/cm$ were observed at 28 monitoring wells while those of higher than $10,000\;{\mu}S/cm$ were done at 9 monitoring wells. From the cross-correlation analysis, groundwater levels were mostly affected by precipitation while temperature and electrical conductivity showed very low correlation. Meanwhile tidal variations strongly affected the groundwater levels comparing to precipitation. We classified the long-term monitoring data according to variation types such as constant process, linear trend, cyclic variation, impulse, step function and ramp. Impulse type was dominant for variations of groundwater level, which was largely affected by rainfall or artificial pumping, the constant process was dominant for temperature. Compared with groundwater level and temperature, electrical conductivities showed various types like linear trend, step function and ramp. According to the discrepancy of variation characteristics for monitoring data at each well in the same region, periodical analysis of monitoring data is essentially required.

    Effects of Bt Cabbage (Brassica oleracea) on the Host Preference and Performance of the Green Peach Aphid, Myzus persicae Sulzer (Hemiptera: Aphididae) (Bt 양배추가 복숭아혹진딧물의 발육과 기주선택에 미치는 영향)

    • Nam, Ki Jung;Kim, Young-Joong;Moon, Doo-Bum;Nam, Kyong-Hee;Pack, In Soon;Park, Jung-Ho;Jeong, Soon-Chun;Harn, Chee Hark;Kim, Chang-Gi
      • 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.


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