• 제목/요약/키워드: Mosquito

검색결과 242건 처리시간 0.031초

Assessment of Organic Compounds Emission from Consumer Products in an Environmental Chamber System

  • Jo, Wan-Kuen;Lee, Jong-Hyo;Lim, Ho-Jin;Kwon, Ki-Dong;Jeong, Woo-Sik
    • Journal of Korean Society for Atmospheric Environment
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    • 제23권E2호
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    • pp.39-46
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    • 2007
  • In order to present the scientific information of organic emissions from consumer products available, the current study examined the emissions composition for three different types of consumer products being used in Korea in an environmental chamber: air freshener (AF), mosquito repellents (MSQR), and moth repellents (MTHR). Emission rates were evaluated by determining emission rates of the target compound from the selected products using an electropolished stainless steel (SS) test chamber $(40{\times}25{\times}50cm^3)$. A time-dependent empirical relationship developed in this study agreed well with the test results. As same with the emission concentrations, MSQR exhibited the highest emission rate for all target compounds except for limonene and naphthalene. MTHR ($9,200\;{\mu}g\;h^{-1}$) showed the highest emission rate of naphthalene followed by MSQR ($8,300\;{\mu}g\;h^{-1}$). Moreover, the concentrations in residential bedroom conditions for target compounds emitted from three types of consumer products were estimated. This estimation suggests that the uses of consumer products can elevate indoor levels of target compounds. In particular, any types of the consumer products may increase the indoor level of m, p-xylene.

The Public Perception and Attitude on the Medical Insects and Pest Control in Korea

  • Lyu, Eun-Soon;Kang, Hye-Sook;Lee, Dong-Kyu
    • Korean Journal of Health Education and Promotion
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    • 제1권1호
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    • pp.1-13
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    • 1999
  • A study has been performed on perception of citizens about the medical insects (house flies, mosquitoes, cockroaches) in Chang Won city. A total of 375 subjects (male: 180, female: 195) was surveyed in October 1997. Cockroaches were the most dislike of medical insects to the dwellers. At a residence, cockroaches were the most troubled insects although mosquitoes were the most frequently appeared insects. Also, the most troubled insects were the cockroaches at hospitals, departments, coffee shops, and bars; the mosquitoes at theaters and parks; and the house flies at restaurants in the city. The cockroaches had the highest negative opinion score as a 4.4 point of a 5.0 point. About half of the subjects had extremely suffered from the mosquitoes (52.8%) and cockroaches (51.8%). House residents controlled house flies using fly swatters (50.0%) and insecticide sprayers (38.9%), but apartment residents controlled them using the sprayers (50.8%) and fly swatters (36.5%). The mosquitoes were controlled by using the sprayers (51.6%) and mosquito coils (36.4%). The cockroaches were controlled by using toxic baits (32.9%) and the sprayers (31.5%). Only 10% of the subjects were satisfied control management against the medical insects. The subjects wanted to more effectively control against cockroaches (39.9%) and mosquitoes (37.9%).

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Essential role of tryptophan residues in toxicity of binary toxin from Bacillus sphaericus

  • Kunthic, Thittaya;Promdonkoy, Boonhiang;Srikhirin, Toemsak;Boonserm, Panadda
    • BMB Reports
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    • 제44권10호
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    • pp.674-679
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    • 2011
  • Bacillus sphaericus produces mosquito-larvicidal binary toxin composed of BinA and BinB. While BinB is expected to bind to a specific receptor on the cell membrane, BinA interacts to BinB or BinB receptor complex and translocates into the cytosol to exert its activity via unknown mechanism. To investigate functional roles of aromatic cluster in BinA, amino acids at positions Y213, Y214, Y215, W222 and W226 were substituted by leucine. All mutant proteins were highly produced and their secondary structures were not affected by these substitutions. All mutants are able to insert into lipid monolayers as observed by Langmuir-Blodgett trough and could permeabilize the liposomes in a similar manner as the wild type. However, mosquito-larvicidal activity was abolished for W222L and W226L mutants suggesting that tryptophan residues at both positions play an important role in the toxicity of BinA, possibly involved in the cytopathological process after toxin entry into the cells.

180° 곡관덕트의 출구영역에 연결된 직관덕트에서 층류유동의 속도분포와 2차유동 (Axial Velocity Profiles and Secondary Flows of Developing Laminar Flows in a Straight Connected Exit Region of a 180° Square Curved Duct)

  • 손현철;이행남;박길문
    • 대한기계학회논문집B
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    • 제29권10호
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    • pp.1092-1100
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    • 2005
  • In the present study, characteristics of steady state laminar flows of a straight duct connected to a 180$^{o}$ curved duct were examined in the entrance region through experimental and numerical analyses. For the analysis, the governing equations of laminar flows in the Cartesian coordinate system were applied. Flow characteristics such as velocity profiles and secondary flows were investigated numerically and experimentally in a square cross-sectional straight duct by the PIV system and a CFD code(STAR CD). For the PIV measurement, smoke particles produced from mosquito coils. The experimental data were obtained at 9 points dividing the test sections by 400 3m. Experimental and numerical results can be summarized as follows. 1) Reynolds number, Re was increased, dimensionless velocity profiles at the outer wall were increased due to the effect of the centrifugal force and secondary flows. 2) The intensity of a secondary flow became stronger at the inner wall rather than the outer wall regardless of Reynolds number. Especially, fluid dynamic phenomenon called conner impact were observed at dimensionless axial position, x/D$_{h}$=50.

Pesticidal Constituents Derived from Piperaceae Fruits

  • Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • 제48권2호
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    • pp.65-74
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    • 2005
  • Fungicidal, insecticidal, and mosquito larvicidal activities of piperidine alkaloids, pipernonaline and piperoctadecalidine, and isobutylamide alkaloids, pellitorine, guineensine, pipercide, and retrofractaminde A, derived from Piperaceae fruits were studied. Pipernonaline and piperoctadecalidine showed potent fungicidal activities against Puccinia recondita with 91 and 80% control values at 500 ppm. Against Phytophthora infestans, pipernonaline showed strong fungicidal activity with 91 and 80% control values at 1,000 and 500 ppm. $LD_{50}$ values of pipernonaline and piperoctadecalidine against Plutella xylostella were 125 and 95.5 ppm, respectively, and that of piperoctadecalidine against Tetranychus urticae was 246 ppm. Against larvae of Aedes aegypti and Culex pipiens pallens, $LD_{50}$ values of pipernonaline were 0.35 and 0.21 ppm, respectively. Highest larvicidal activities of pipercide and retrofractamide A were found against A. aegypti, A. togoi, and C. pipiens pallens. $LD_{50}$ values of pipercide and retrofractamide A were 0.10 and 0.039 ppm against A. aegypti, 0.26 and 0.01 ppm against A. togoi, and 0.004 and 0.028 ppm against C. pipiens pallens, respectively. Based upon these results and earlier findings, bioactive components derived from Piperaceae fruits may be valuable for development of useful lead product of possibly safer fungicidal, insecticidal, and mosquito larvicidal agents.

Larvicidal Activity of Chamaecyparis obtusa and Thuja orientalis Leaf Oils against Two Mosquito Species

  • Jeon, Ju-Hyun;Lee, Sang-Hyun;Kim, Moo-Key;Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • 제48권1호
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    • pp.26-28
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    • 2005
  • Evaluation of larvicidal activities of Chamaecyparis obtusa and Thuja orientalis oils against 4th-instar larvae of Aedes aegypti and Culex pipiens pallens revealed larvicidal activities of leaf oils extracted from C. obtusa and T. orientalis were significantly higher than those of stem, fruit, and seed oils. Strong mortality was observed in age class II of C. obtusa and T. orientalis against Ae. aegypti and Cx. pipiens pallens larvae. These results show both leaf part and age class II of C. obtusa and T. orientalis have strong larvicidal activity against Ae. aegypti and Cx. pipiens pallens. Leaf oils of C. obtusa and T. orientalis leaves show promise as natural larvicides against Ae. aegypti and Cx. pipiens pallens.

모기유충 방제균 Bacillus sphaericus 1593의 형질전환 조건 (Transformation of Mosquito Larvicidal Bdillus sphaericus 1593 by Plasmid pGB215-110$\Delta$B)

  • 한길환;김상달
    • 한국미생물·생명공학회지
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    • 제23권2호
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    • pp.156-163
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    • 1995
  • Bacillus sphaericus 1593 is pathogenic to the larvae of a number of mosquito species that are known as important vectors for the transmission of certain human and animal diseases. As a preliminary experiment for developing a multfunctional B. sphaericus 1593 as a potent antagonist, we investigated the conditions for the protoplast transformation system of B. sphaericus 1593 using the plasmid pGB215-110$\Delta$B. The protoplast of B. sphaericus 1593 were obtained most efficiency by treating the cells with 500 $\mu$g/ml of lysozyme in the SMM buffer containing 0.5 M sucrose at pH 8.0 and 40$\circ$C for 60 minutes. The cell wall was regenerated on the plate containing 1.2% agar and 0.8 M mannitol. Under the best condition for protoplast formation and regeneration established in the work the highest frequency of transformation was achieved with the 40% PEG (M.W 4,000) treatment for 15 minutes of incubation at 4$\circ$C, and subsequently for 120 minutes incubation at 30$\circ$C for phenotypic expression. The highest transformation efficiency were observed at 1.0 $\mu$g/ml of the final concentration of the plasmid DNA and the plasmids were found to be fairly stable since about 70% of the plasmids were maintained after 8 successive daily transfers onto the fresh medium.

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정사각단면 곡관덕트에 연결된 직관덕트에서 층류유동의 속도분포 (A Study on the Axial Velocity Profile of Developing Laminar Flows in a Straight Duct Connected to a Square Curved Duct)

  • 손현철;이행남;박길문;이홍구
    • 대한기계학회논문집B
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    • 제28권9호
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    • pp.1058-1065
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    • 2004
  • In the present study, characteristics of steady state laminar flows of a straight duct connected to a 180$^{\circ}$ curved duct were examined in the entrance region through experimental and numerical analyses. For the analysis, the governing equations of laminar flows in the Cartesian coordinate system were applied. Flow characteristics such as velocity profiles, and secondary flows were investigated numerically and experimentally in a square cross-sectional straight duct by the PIV system and a CFD code(STAR CD). For the PIV measurement, working fluid produced from mosquito coils smoke. The experimental data were obtained at 9 points dividing the test sections by 400 mm. Experimental and numerical results can be summarized as follows. Critical Reynolds number, Recr which indicates transition from laminar steady flow to transition steady flow was 2,150. As Reynolds number, Re, was increased, dimensionless velocity profiles at the outer wall were increased due to the effect of the centrifugal force and the secondary flows. The intensity of a secondary flow became stronger at the inner wall rather than the outer wall regardless of Reynolds number.