• Title/Summary/Keyword: natural mortality

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Comparative Toxic Effects of Gramoxone in the D. melanogaster and its Sibling Species (노랑초파리(Drosophila melanogaster)와 그 동포종들에 있어서 Gramoxone의 독성에 관한 비교 연구)

  • Choi, Yung-Hyun;Lee, Won-Ho;Yoo, Mi-Ae
    • Journal of Environmental Science International
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    • v.1 no.2
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    • pp.1-13
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    • 1992
  • Physiological toxic and mutagenic effects of gramoxone in Drosophila melanogaster were invetigated. Gramoxone was highly toxic on the development, resulting in of lowering the viability and in prolongation of the developmental times. Adults treated with gramoxone during the developmental stages caused a lowering of the productivity and a little chinge in protein quantity. But the effect on the sex-linked lethal mutagenesis was found to be negative. The order of mortality causing ado리t stoa형e feeding to gramoxone in the D. melanogaster complex was like this ; D. mauritiana, D. sechellia, D. simulans and D. melanogasteu Two species of the D. yakuba complex were alike. Those results were more or less correlation with speciation of the D. melanogaster subgroup.

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Pharmacophore Based Screening and Molecular Docking Study of PI3K Inhibitors

  • Rupa, Mottadi;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.9 no.1
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    • pp.41-61
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    • 2016
  • Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. Phosphoinositide 3-kinases (PI3Ks) play important role in Non-Small Cell Lung Cancer. PI3Ks constitute a lipid kinase family which modulates the function of numerous substrates involved in the regulation of cell survival, cell cycle progression and cellular growth. Herein, we describe the ligand based pharmacophore combined with molecular docking studies methods to identify new potent PI3K inhibitors. Several pharmacophore models were generated and validated by Guner-Henry scoring Method. The best models were utilized as 3D pharmacophore query to screen against ZINC database (Chemical and Natural) and the retrieved hits were further validated by fitness score, Lipinski's rule of five. Finally four compounds were found to have good potential and they may act as novel lead compounds for PI3K inhibitor designing.

Chemical Components, Antitermite and Antifungal Activities of Cinnamomum parthenoxylon Wood Vinegar

  • ADFA, Morina;ROMAYASA, Ari;KUSNANDA, Arif Juliari;AVIDLYANDI, Avidlyandi;YUDHA S., Salprima;BANON, Charles;GUSTIAN, Irfan
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.1
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    • pp.107-116
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    • 2020
  • Termiticidal and fungicidal activities of wood vinegar from Cinnamomum parthenoxylon (CP) stem wood have been evaluated against Coptotermes curvignathus and wood rotting fungi (Schizophyllum commune and Fomitopsis palustris). The utilized CP wood vinegar was produced in the operating temperature range 250-300℃ pyrolysis. A no-choice test was applied for evaluating termiticidal activity with 33 active termites and antifungal activity using the agar media assay. The result showed that an increase in the concentrations of CP wood vinegar significantly raised the mortality of termite. CP wood vinegar showed high termiticidal activity, organic acids (acetic acid 42.91%, 3-butenoic acid 6.89%, butanoic acid, 2-propenyl ester 2.26%), and ketones (1-hydroxy-2-propanone 5.14%, 3-methylcyclopentane-1,2-dione 2.34%) might be largely contributed to termiticidal activity in addition to other minor components. Furthermore, CP wood vinegar exhibited significant inhibition of fungal growth. These data showed that CP wood vinegar was more toxic to white-rot fungi (S. commune) than brown-rot (F. palustris). The results suggested that phenolic compounds from lignin degradation were responsible for good antifungal activity.

Population Ecological Characteristics of the Soft-shelled Clam, Mya japonica in the Intertidal Zone of South Sea in Korea (한국 남해안 조간대에 서식하는 우럭, Mya japonica의 자원생태학적 특성)

  • 이선길;장창익
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.3
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    • pp.234-243
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    • 2000
  • This paper is to study population ecological characteristics, including growth parameters, survival rate, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the soft-shelled clam, Mya japonioa in the intertidal zone of South Sea in Korea. For describing growth of the clam a von Bertalanffy growth model was adopted, The von Bertalanffy growth curve had an additive error structure and the growth parameters estimated from a non-linear regression were SH/sub ∞/=79.83mm, K=0.26, and t/sub 0/= -0.01. Survival rate (S) of the soft-shelled clam was 0.26 (SD=0.02). The instantaneous coefficients of natural mortality (M) was estimated to be 0.78/year and fishing mortality (F) 0.57/year for the soft-shelled clam. The age at first capture (t/sub c/) was estimated as 2.69 year. The mean densities of the soft-shelled clam by bottom type were 3.40 inds./m²(SE=0.18) in the sand, 63.4 inds./m²(SE= 0.53) in the muddy sand, and 0 inds./m2 (SE=0) in the gravelly sand. The mean densities of the soft-shelled clam by 3 different areas were 4.88 inds./m²(SE=0.09), 2.61 inds./m²(SE=0.13), 7.20 inds./m²(SE=0.18), respectively and the biomass of the clam were estimated as 131mt, 121mt, 665mt, respectively. An yield-per-recruit analysis showed that the current yield-per-recruit of about 8.30g with F=0.57/year and the age at first capture (t/sub c/) 2.69 year, was lower than the maximum possible yield-per-recruit of 9.60g. Fixing to at the current level and increased fishing intensity (F) could produce an increase in the predicted yield-per-recruit from 8.30g to about 9.40. However, estimated yield-per-recruit increased to 1.30g by decreasing to from the current age (2.69 year) to age two with F fixed at the current level. Yield-per-recruit was estimated under harvest strategies based on F/sub max/ and F/sub 0.1/.

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Molluscicidal Effect of Eco-Friendly Agricultural Substances for Controlling Golden Apple Snails (Pomacea canaliculata, Lamarck)

  • Il Kyu Cho;Woo Young Cho;In Sun Cho;Heon Woong Kim;Seonghoon Hyeong;Jang Hyun Park;Young Sig Kim;Kil Yong Kim;Gi-Woo Hyoung
    • Korean Journal of Environmental Agriculture
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    • v.42 no.4
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    • pp.396-407
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    • 2023
  • The golden apple snail (Pomacea canaliculata) has been utilized as a natural and eco-friendly control of weeds in rice paddy fields. However, P. canaliculata can damage other crops. In this study, the effectiveness of plant extracts from various natural sources that are reportedly effective against pests in the control of P. canaliculata was investigated. The four plant extracts were effective against P. canaliculata and ranked in descending order as green tea seed (Camellia sinensis) > root of red spider lily (Lycoris radiata) > leaves of tobacco (Nicotiana tabacum) > root of sophora (Sophora flavescens). The mortality rate of P. canaliculata was increased using 200 to 2000 mg/kg of green tea seed powder. However, shrubby sophora root extract did not significantly increase the mortality rate. The LC50 and LC90 of green tea seed, tobacco leaves, shrubby sophora root, and red spider lily root were 900 and 2800 mg/L, 956 and 2320 mg/L, 2162 and 5325 mg/L, and 512 and 1054 mg/kg, respectively. The LC50 and LC90 of ground powder of C. sinensis, N. tabacum, S. flavescens and L. radiata were 248 and 646 mg/L, 403 and 733 mg/L, 409 and 905 mg/L, and 493 and 1141 mg/L, respectively. The findings indicate the remarkable control potency of green tea seeds against the golden apple snail. An organic material incorporating the four plant powders may help control green apple snail in an ecosystem-friendly manner.

The Study on the Sexual Difference in the Cause and the Time of Casualty and in the Size of the Fairy Pitta (Pitta nympha) through DNA Analysis in Republic of Korea (DNA 분석에 의한 팔색조의 암수 구분 및 암수별 피해 현황 그리고 크기 차이에 관한 연구)

  • Kim, Eun-Mi;Jeon, Yeon-Seon;Jeong, Gil-Sang;Kim, Se-Jae;Kang, Chang-Wan;Oh, Mi-Rea;Noh, Pu-Reum;Won, Hyun-Kyu
    • Journal of Environmental Science International
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    • v.23 no.8
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    • pp.1447-1453
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    • 2014
  • The differentiation of sex is important for species preservation. However, Fairy Pitta is sexually monomorphic and sex of an individual is indistinguishable with its external characteristics. We determined the sex of Fairy Pitta through DNA analysis and investigated the causes and time of injury and mortality and the size based on sex. We collected 21 samples at Jeju Island, Korean Peninsula from 2004 to 2013 and extracted DNA from them and amplified chromo helicase DNA-binding gene from Z and W chromosomes through Polymerase Chain Reaction (PCR). We confirmed their sex with the banding pattern through Agarose gel electrophoresis, i.e. male (ZZ): one banded and female (ZW) two banded. We distinguished the sex of 17 of 21 samples resulting in 9 males and 8 females. Most casualties were recorded in adult of both sexes. Causes of injury and mortality proved that female casualties occurred from window strikes, dehydration, car accident, predation by natural enemies, and male occurred from window strikes, car accident and dehydration. The time of injury and mortality in adults differ by sex. There was no difference between sexes in any of the six size parameters. As the time of injury and mortality differ by sex, the survey on the role and ecological nature by sex in breeding season must be carried out in the future. External measurements may not be reliable for sexing of Fairy Pitta and other traits such as vocal or characteristics are required to identify the sex of individuals in the field.

Analyses on Environment-friendliness of Waterproof Materials Based on Fish Toxicity Test (어독성 실험에 따른 방수재 친환경 특성 분석)

  • Kim, Sung-Kyun;Woo, Ji-Keun;Lee, Im-Gyu;Yoo, Hy-Ein;Jeong, Jae-Wook
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.1
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    • pp.57-68
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    • 2010
  • The purpose of this study is to analyze the characteristics of environment-friendliness of waterproof materials based on comprehensive experiments on waterproofness in terms of coefficients of permeability, harmfulness of waterproof materials and fish toxicity of Oryzias latipes mortality to verify eco-toxicity of each method of construction and waterproof material, which are to be applied by taking eco-toxicity into account when building ecological flows in upper areas on natural and artificial grounds. As a result, the following conclusions have been reached in this study: 1. In regard of the harmfulness analyzed, each material showed a different result of analytical value in each lab tank. Compared to input water, pH, COD, SS, T-P, and T-N values increased a little, but DO value decreased. The value of turbidity analyzed independent of the water quality standard of aquatic ecosystem set forth by the Ministry of Environment increased a little compared to the value in input water. 2. In the experiment of fish toxicity, compacted quicklime, cement fluid waterproof material, cement mortar waterproof material and bentonite powder were found to have 100% of fish mortality, respectively, and membrane waterproof material showed 83.3% of mortality, indicating strong fish toxicity. Improved asphalt sheet (63.3%) and synthetic rubber sheet (53.3%) were analyzed to have medium fish toxicity, while bentonite sheet (6.7%), Hwang-toh (6.7%) and clay (3.3%) showed relatively lower mortality and fish toxicity. 3. Regarding the analysis on waterproofness in terms of the coefficient of permeability of each waterproof material, improved asphalt sheet, synthetic rubber sheet, membrane waterproof material, cement fluid and mortar waterproof material and bentonite sheet were found impervious in case no leakage takes place in construction. Bentonite powder was found practically impervious based on the analytical results from the experiment done in compliance with weight ratios. So were the clay and Hwang-toh from the experimental results. To sum up such results as found in the experiment mentioned so far, the values of harmfulness and waterproofness analyzed were different in each lab tank, but there was absolutely little correlation with the mortality gained from the experiment on fish toxicity. In the experiment of fish toxicity, environment-friendly waterproof materials were analyzed, and it was found that clay, Hwang-toh and bentonite sheet are highly environment-friendly. In contrast, synthetic rubber and improved asphalt sheets were found to have medium-level environment-friendliness. Also, membrane water-proof materials, compacted quicklime, cement fluid and mortar waterproof material and bentonite powder were analyzed to have low environment-friendliness.

Effects of Root Zone Applications of Some Systemic Insecticides for Control of the Brown Planthopper, Nilaparvata lugens ($St{\aa}l$) (Homoptera: Delphacidae) (벼멸구에 대한 여러 가지 침투성 살충제의 근부처리 효과)

  • Pham, Hong-Hien;Kim, Jong-Kyu;Choi, Byeong-Ryeol;Song, Yoo-Han
    • The Korean Journal of Pesticide Science
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    • v.12 no.3
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    • pp.236-242
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    • 2008
  • Laboratory and greenhouse experiments were conducted to evaluate the effect of root zone application of some systemic insecticides for control of the brown planthopper (BPH), Nilaparvata lugens, as one of the management option to minimize the adverse effects and maximize the efficacy of insecticide application. Five systemic insecticides, namely, carbofuran, carbosulfan, diazinon, ethoprophos and imidacloprid, as granular formulation were placed in the root zone and measured the mortality, fecundity, and nymphal survivorship of the planthopper. Diazinon and ethoprophos did not show the significant mortality of the BPH. When the BPH were inoculated at the day of carbofuran treatment, adult mortality was shown almost 100% at seven days after treatment and BPH nymphs were remained very few on rice at 25 days after treatment. When carbofuran were placed 10 days before the BPH inoculation, it showed almost 100% adult mortality after one day, and no nymphs were found until 25 day after inoculation. Efficacy of carbofuran on BPH when applied in 10 day-old rice was higher than in 30 day-old rice. These results indicated that the root zone application of carbofuran can control N. lugens effectively with less adverse effect to the natural enemies inhabited on rice plants.

Effects of Changes in Fishing Effort on Yield of Kuwait's Commercial Fish Stocks

  • LEE J. U.
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.6
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    • pp.475-483
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    • 1990
  • An assessment of Kuwait's commercial fish stocks: hamoor (Epinephelus tauvina), zobaidy (Pampus argenteus), nakroor (Pomadasys argenteus) and sheiry (Lethrinus nebulosus), was conducted using length-frequency data, mean growth and mortality estimates obtained during 1981$\~$1988. The length-cohort analysis indicated that increases in fishing effort would not lead to long-term gains in yield of the stocks at the current estimate of natural mortality rate (M). At high M which was assumed arbitrarily, some benefit in yield could be obtained, especially for hamoor and sheiry. At low M, the yield of all stocks decreased with increased fishing effort. Increases in fishing effort resulted in significant dec-line in spawning stock size for all the stocks. Yield-per-recruit analysis indicated that, un-der low M assumption, a higher yield can be obtained for zobaidy and nakroor by reducing fishing effort. At moderate M, decreases in fishing effort brought gains in yield per recruit of the stocks, but it was not substantial compared with the present level of M. At high M, most of the stocks reached the maximum yield-per-recruit. Overall, increased fishing effort either will not be associated with large long-term gains in yield or, in some stocks, might cause a decline from the present level.

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Ecologically Sustainable Management of Short-necked Clam, Ruditapes philippinarum, on the Coast of Yeongi at Tongyeong, Korea (통영 연기해역의 바지락자원 적정관리에 관한 연구)

  • Cho, Sang-Man;Jeong, Woo-Geon;Lee, Sang-Jun
    • The Korean Journal of Malacology
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    • v.24 no.3
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    • pp.189-197
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    • 2008
  • In order to develop the sustainable ecological management, short-necked clams, Ruditapes philippinarum, were collected from Yoengi coast in Tongyoeng, Korea. The growth of the clam was estimated as: $L_f=68.08{\cdot}(1-e^{-0.145(t+0.324)})$ from ring radius composition of shell. Instantaneous co-efficiency of total mortality and natural mortality were calculated as: 0.991/year and 0.494/year, respectively. The age of the clams from the first capture was estimated to be 3.28. The total biomass was estimated to be 212 MT in the fisheries area (6.4 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit were calculated to be 649.5 individual/$m^2$ and $0.7\;g/m^2$, respectively. The current fishing intensity was much lower for maximum sustainable yield and acceptable biological catch. Although higher yield per recruit could be achieved by increasing fishing intensity, it is favorable to retain the current fishing intensity because of the unique fishing attitude on Yeongi coast in Tongyoeng, Korea.

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