• Title/Summary/Keyword: condition factor (k)

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Optimal temperature conditions of Korean freshwater Cladoceran for development of standard toxicity test methods (표준생태독성시험법 개발을 위한 한국산 물벼룩의 최적사육온도 구명)

  • Kim, Byung-Seok;Park, Yoen-Ki;Park, Kyung-Hun;Shin, Jin-Sup;Kim, Jin-Hwa;Ahn, Young-Joon
    • The Korean Journal of Pesticide Science
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    • v.9 no.3
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    • pp.221-230
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    • 2005
  • Temperature is an important ambient factor affecting the physiology and metabolism of aquatic invertebrates. In this study, we studied about the survival, reproduction and growth effects of 4 different temperatures(16, 20, 24, $28^{\circ}C$) in four Korean cladoceran, Daphnia sp., Daphnia obtusa, Moina macrocopa, Simocephalus vetulus and Daphnia magna as an international standard species. All 5 water flea tested showed that molting time, fecundity and intrinsic rate of natural increase(r) in high temperature condition were higher than those in lower temperature. On the other hand, lower survivals and longer time to start of offspring were showed in high temperature. Our results suggest that the optimal temperatures of Daphnia sp.,, Moina macrocopa and Simocephalus vetulus seem to be about $20^{\circ}C$ except for Daphnia obtusa which as showed good survivals and reproductions in $16^{\circ}C$.

The Optimum Conditions for Screening of Salt Resistant Lines Through Embryo Culture in Panax ginseng C.A. Meyer (인삼 염류내성 계통의 선발을 위한 배배양 배지조건)

  • Yang, Deok-Chun;Lee, Eun-Kyung;Kwon, Woo-Saeng
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.2
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    • pp.161-166
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    • 2003
  • Korean ginseng(Panax gmseng C.A. Meyer) is very difficult to obtain stable production of qualified ginseng roots because of variable stresses in soil environments. In environment stresses, soil condition is the most important factor, among which nutrients, especially inorganic materials such as N, P, K, Ca, Mg, Fe, etc., influence greatly on the ginseng growth. However, present ginseng field soils in Korea contain so much amount of such inorganic materials that a variety of remarkable disorders were noted in many ginseng plantations, resulting in decrease of qualitative ginseng production. Therefore, it is required to search for genetic resources and genes tolerant to salt stress for the development of ginseng cultivars. Selection of stress-tolerant ginseng lines in fields is very difficult because it is almost impossible to control properly the environmental conditions of soil. On the contrary, it can be studied with ease to search for stress-tolerant ginseng lines through in vitro culture because of easy manipulation of stress conditions. Murashige & Skoog(MS) media with 2.5 folds of $KNO_3,\;NH_4NO_3,\;MgSO_4\;7H_2O,\;KH_2PO_4,\;and\;CaCl_2\;2H_2O$ was established for the selection of ginseng lines tolerant to salt stress under the embryo culture.

A Study on the $SO_2/CO_2/N_2$ Mixed Gas Separation Using Polyetherimide/PEBAX/PEG Composite Hollow Fiber Membrane (Polyetherimide/PEBAX/PEG 복합 중공사막을 이용한 $SO_2/CO_2/N_2$ 혼합기체 분리에 관한 연구)

  • Hyung, Chan-Heui;Park, Chun-Dong;Kim, Kee-Hong;Rhim, Ji-Won;Hwang, Taek-Sung;Lee, Hyung-Keun
    • Membrane Journal
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    • v.22 no.6
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    • pp.404-414
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    • 2012
  • In order to investigate $SO_2$ removal, PEI hollow fiber membranes were produced by a dry-wet phase inversion method. The membrane support layer on surface was coated with PEBAX1657$^{(R)}$ and PEG blending materials. Modules were prepared for the single gas permeation characteristics of composite membrane according to temperature and pressure. As a result, $SO_2$ permeance and $SO_2/N_2$ selectivity were 220~1220 GPU and 100~506 through operating condition, respectively. Moreover, $SO_2/CO_2/N_2$ mixture gas was used to compare the performance of separation properties according to temperature, pressure and retentate flow rate difference. $SO_2$ removal efficiency was increased with pressure and temperature.

Effect of Storage Condition on the Germination of Scrophularia buergeriana and Scrophularia takesimensis (현삼 및 섬현삼 종자의 저장조건에 따른 발아특성 연구)

  • Lee, Jeong Hoon;An, Chanhoon;Lee, Yun Ji;Kim, Seong Chul;Jung, Chan Sik;Kim, Seong Min
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.5
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    • pp.393-400
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    • 2016
  • Background: This study was conducted to investigate the effects of germination temperature, storage container and storage temperature on Scrophularia buergeriana and Scrophularia takesimensis seeds. Methods and Results: Seed lengths of both species were 0.8 mm, while seed width differed, with S. buergeriana measuring 0.5 mm and S. takesimensis measuring 0.4 mm. The seeds of S. buergeriana were packaged in paper containers under room temperature ($15^{\circ}C$), cold temperature ($4^{\circ}C$), and freeze temperature ($-20^{\circ}C$). These seeds exhibited around 80% germination rate at temperatures between $15^{\circ}C$ and $30^{\circ}C$. The germiantion rate of S. takesimensis, on the other hand, differed significantly at different germination temperatures. Seeds of S. takesimensis which were packaged in vinyl and paper containers and stored under room and cold temperatures, exhibited around 80% germination rate at $15^{\circ}C$. However, the germination rate of freeze-stored seeds were decreased to lower than 20% at germination temperatures of $15^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ germiantion conditions. The rate of germination showed a low positive to a significantly negativie correlation with the other factor that were determined to evaluate the germination performance. Conclusions: This study elucidates the most suitable germination and storage conditions to increase the germination rate for the two species of Scrophularia buergeriana and Scrophularia takesimensis needs to be stored in paper containers under cold temperature and requires a temperature of $20^{\circ}C$ for germination. On the other hand, S. takesimensis in vinyl containers need to be stored at room temperature and those in paper containers at cold temperature, and a temperature of $15^{\circ}C$ is required for germination.

A Geochemical Study on Pyrophyllite Deposits and Andesitic Wall-Rocks in the Milyang Area, Kyeongnam Province (경남 밀양지역 납석광상과 안산암질 모암의 지구화학적 연구)

  • Oh, Dae-Gyun;Chon, Hyo-Taek;Min, Kyoung-Won
    • Economic and Environmental Geology
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    • v.25 no.1
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    • pp.27-39
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    • 1992
  • Several pyrophyllite deposits occur around the Milyang area where Cretaceous andesitic rocks and spatially related granitic rocks are widely distributed. Pyrophyllite ores consist mainly of pyrophyllite, and quartz with small amount of sericite, pyrite, dumortierite, and diaspore. The andesitic rocks and spatially related granitic rocks in this area suggest that they could be formed from the same series of a calc-alkaline magma series. The contents of $SiO_2$, $Al_2O_3$, LOI(loss on ignition) are enriched, and $K_2O$, $Na_2O$, CaO, MgO, $Fe_2O_3$ are depleted in altered andesitic rocks and ores. Enrichment of As, Cr, Sr, V, Sb and depletion of Ba, Cs, Ni, Rb, U, Y, Co, Sc, Zn are characteristic during mineralization. The pyrophyllite ores can be discriminated from the altered-and unaltered wall-rocks by an increasing of $(La/Lu)_{cn}$ from 4.18~22.13 to 8.98~55.05. In R-mode cluster analysis, Yb-Lu-Y, La-Ce-Hf-Th-U-Zr, $TiO_2-V-Al_2O_3$, Sm-Eu, $CaO-Na_2O-MnO$, Cu-Zn-Ag, $K_2O-Rb$ are closely correlated. In the discriminant analysis of multi-element data, $P_2O_5$, As, Cr and $Fe_2O_3$, Sr are helpful to identify the ores from the unaltered-and altered wall-rocks. In the factor analysis, the factors of alteration of andesitic rocks and ore mineralization were extracted. In the change of ions per unit volume, $SiO_2$, $Al^{3+}$ and LOI are enriched and $Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Mn^{2+}$ and $Fe^{3+}$ are depleted during the alteration processes. The Milyang and the Sungjin pyrophyllite deposits could be mineralized by hydrothermal alteration in a geochemical condition of low activity ratio of alkaline ions to hydrogen ion with reference to spatially related granitic rocks.

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Persistence and Dislodgeable Residues of Chlorpyrifos and Procymidone in Lettuce Leaves under Greenhouse Condition (상추의 생산단계별 Chlorpyrifos 및 Procymidone의 잔류허용기준 설정)

  • Kim, Young-Sook;Park, Ju-Hwang;Park, Jong-Woo;Lee, Young-Deuk;Lee, Kyu-Seung;Kim, Jang-Eok
    • Korean Journal of Environmental Agriculture
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    • v.21 no.2
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    • pp.149-155
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    • 2002
  • Two pesticides commonly used for lettuce cultivation including chlorpyrifos and procymidone were subjected to a field residue trial to ensure safety of terminal residues in the harvest. After pesticides were applied at standard and double rates in a foliar spray, leaf persistence of their residues was investigated far 10 days prior to harvest. Even though far exceeded the tolerances, initial leaf residues were rapidly dissipated with time and remained only 0.4$\sim$7.2% of the residues in the harvest. As well fitted by the first-order kinetics, biological half-lives of the pesticide residues in lettuce leaves ranged 1.2$\sim$2.6 days. Slow dissipation of the residues in the harvest was observed during storage at room temperature and 4$^{\circ}C$ for 7 days. Portions of dislodgeable residues which resided in detergent washings decreased as time elapsed. Patterns in dissipation and distribution of dislodgeable residues were not largely affected by the application rate of pesticides. It is concluded that timing of pesticide application, that is, pre-harvest interval would be the first factor to determine the terminal residue level in edible portions of lettuce.

The Improved Antigen-binding Activity of Biosimilar Remicade ScFv Antibodies by Fusion of the Leucine Zipper Domain (Leucine zipper도메인의 융합에 의한 바이오시밀러 레미케이드 Single-chain Fv 항체의 항원 결합력 개선)

  • Kim, Jin-Kyoo;Kim, Tae Hwan
    • Journal of Life Science
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    • v.30 no.11
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    • pp.1012-1020
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    • 2020
  • Remicade is a therapeutic biosimilar natural antibody in which the mouse variable domain has been linked to the human constant domain. It is a chimeric monoclonal antibody specific to tumor necrosis factor-alpha (TNF-α) and has been developed for the treatment of rheumatoid arthritis. To investigate the biological activity of the Remicade antibody, we carried out a bioinformatics study using a protein data bank to characterize the TNF-α antigen binding mechanism of the Remicade natural antibody. Because the production of the Remicade antibody is often limited by genetic instability of the natural antibody-producing cell, we generated a Remicade single-chain variable domain fragment antibody (Remicade) in which a heavy chain variable domain (VH) is joined with a light chain variable domain (VL) by a polypeptide linker. Furthermore, Remicade was fused to a leucine zipper (RemicadeScZip) for higher production and higher antigen-binding activity than Remicade. The Remicade and Remicade ScZip were expressed in Escherichia coli and purified by a Ni+-NTA-agarose column. As expected, the purified proteins had migrated as 28.80 kDa and 33.96 kDa in sodium dodecyl sulfate-polyacrylamide electrophoresis. The TNF-α antigen binding activity of Remicade was not observed by ELISA and western blot. In contrast, RemicadeScZip showed antigen-binding activity. Additional bio-layer interferometry analysis confirmed the antigen-binding activity of RemicadeScZip, suggesting that the leucine zipper stabilized the folding of RemicadeScZip in a denatured condition and improved the TNF-α antigenbinding activity.

Length and Weight Relationship for Two Dominant Antarctic Notothenioid Fishes Caught in the Coastal Water off King Sejong Station, King George Island, Antarctica (남극, 킹조지섬, 세종과학기지 연안에 우점하는 남극암치아속 어류 두 종의 길이와 무게의 관계)

  • Park, Hyun;Kim, Il-Chan;Kang, Seunghyun;Kim, Bo-Mi;Han, Dong-Won;Kim, Jin-Hyoung
    • Korean Journal of Ichthyology
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    • v.29 no.2
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    • pp.146-150
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    • 2017
  • Length and weight relationship (LWR) for dominant Antarctic fishes was determined in two species of the family Nototheniidae; black rockcod (Notothenia coriiceps) and marbled rockcod (Notothenia rossii). Samples were caught in the offshore sea around King Sejong station located on King George Island, Antarctica in January, 2017. A total of 30 N. coriiceps and 7 N. rossii were caught by fishing rod and hook. Average total length was 266.0 mm for N. coriiceps and 275.4 mm for N. rossii. Average total weight was 283.1g for N. coriiceps and 290 g for N. rossii. In terms of LWR and b value, the results showed that both two species had positive allometries (b>3) in good health. This size information of two dominant Antarctic fishes would be useful for future physiological studies to understand of adaptation mechanism and biological pathway of Antarctic marine organisms.

Effect of Soil Salinity and Soil-wetting by Summer-Rising of Water Table on the Growth of Fruit Trees Transplanted at the Saemangeum Reclaimed Tidal Land in Korea (새만금간척지의 토양염농도와 지하수위의 하계 상승이 이식한 과수의 생육에 미치는 영향)

  • Sohn, Yong-Man;Jeon, Geon-Yeong;Song, Jae-Do;Lee, Jae-Hwang;Kim, Doo-Hwan;Park, Moo-Eon
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.1
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    • pp.8-15
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    • 2010
  • The effect of soil salinity and soil-wetting by rise of water table on the growth of fruit trees was studied to obtain information for orchard establishment in the Saemangeum reclaimed tidal land. Survival ratio of trees was 85%for grape, 31%for fig, 15%for apple and pear, and near zero for peach and blueberry. Wet injury induced by water-logged or flooded condition, rather than salt injury(soil EC was lower than 3.0dS $m^{-1}$ during growing period) is thought to be more responsible for low survival ratio of fruit trees transplanted in Saemangeum area. During the summer raining season in the reclaimed areas, the soil salinity tends to be decreased by natural rainfall effect, and the rainfall acceptable capacity(RAC) of soils dramatically is reduced(10-24 mm) as rainfall is continued to occur. In spite of high hydraulic conductivity(121 cm $day^{-1}$) of soils across the area, low RAC of soils might be due to high soil saturation and elevated water table during summer raining season. Therefore, the installation of effective drainage system should be the primary factor determining successful establishment of orchard in the Saemangeum reclaimed tidal land.

An Experimental Study on the Evaluation of Smear Effect Considering In-situ Conditions (현장여건을 고려한 스미어 영향 평가에 관한 실험적 연구)

  • Park, Yeong-Mog
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.8
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    • pp.85-94
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    • 2012
  • Evaluation of the smear effect caused by mandrel penetration into soft ground for a vertical drain installation is very important to predict the consolidation time of soft ground improvement. 30 kinds of laboratory model tests considering in situ conditions were conducted to investigate the formation of a smear zone and the decrease of coefficient of permeability in the disturbed zone. Three types(C(clay):M(silt)=1:1, 0.5:0.5, and 0:1) of reconstituted samples were used for 3 dimensional smear zone test. An experimental study was performed focusing on length of mandrel penetration, mandrel shape and size, earth pressure, and ground condition(unit weight and grain size distributions). Laboratory test results show that the length of mandrel penetration is the most critical factor for the formation of smear zone. As a result, the ratio between diameter of the smear zone($d_s$) and that of mandrel($d_m$) at field using long mandrel becomes larger than conventional $d_s/d_m$. The ratio between $d_s$ and $d_m$ ranges from 1.89 and 2.48 with the sample at C:M=1:0. It was also found that the $d_s/d_m$ value with the round shape of the mandrel is smaller than that of diamond one. The value of $d_s/d_m$ decreased with larger mandrel size, lower unit weight, and higher earth pressure. However, higher silt content led to increase of $d_s/d_m$. The ratio between coefficient of horizontal permeability in the smear zone($k_{hs}$) and that of undisturbed zone($k_{ho}$) ranged from 0.70 to 0.85. The test results imply that factors and values affecting $k_{hs}/k_{ho}$ show similar tendency with $d_s/d_m$.