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Developmental Potentials of Clone Embryos Derived from Bovine Fetal Fibroblast Cells (소 태아섬유아세포 유래 복제란의 발육능에 관한 연구)

  • Cheong, H.T.;Kwon, D.J.;Park, Y.S.;Hwang, H.S.;Park, C.K.;Yang, B.K.;Kim, C.I.
    • Korean Journal of Animal Reproduction
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    • v.24 no.1
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    • pp.49-57
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    • 2000
  • This study was conducted to investigate the developmental potential of cloned embryos derived from bovine fetal fibroblast cells, and the effect of quiescent treatment, passage number and origin of donor cells on in vitro development of cloned embryos. Fetal skin and liver-derived fibroblast cells were transferred to enucleated oocytes after serum starvation or nontreatment (cycling). After electrofusion. reconstituted embryos were activated with $Ca^{++}$-ionophore and cycloheximide, and cocultured for 7~9 days with BRL cells. Some blastocysts were transferred to recipient cows 7~8 days post estrus. The development rate to the blastocyst stage of serum starved cell-derived embryos was higher (25.3%) than that of actively dividing cells-derived embryos (15.9%), The rates of blastocyst formation were 23.1~25.0% after transfer of cell passaged 4 to 6 times, and 23.8 and 25.2% after transfer of fetal skin and liver cells, respectively. After embryo transfer, 34.4% and 15.6% of recipient cows were pregnant on Day 60 and 120, respectively, and one male calf was produced from skin-derived vitrified blastocyst. The result of this study showed that the development of cloned embryos. was enhanced by quiescent treatment, but did not different among the cells passaged 4 to 6 times, and between skin and liver cells. This result also confirms that offspring can be obtained from the vitrified clone embryo derived from fetal skin cell.

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Physicochemical Characteristics of Ethanol Extracts from Each Part of the Pleurotus eryngii (새송이버섯(Pleurotus eryngii) 부위별 추출물의 이화학적 특성)

  • Ahn, Myung-Soo;Kim, Hyun-Jeung;Seo, Mi-Sook
    • Journal of the Korean Society of Food Culture
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    • v.21 no.3
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    • pp.297-302
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    • 2006
  • This study has examined the physicochemical properties of the Pleurotus eryngii, including their proximate components, amount mineral content, total dietary fiber, total sugar, reducing sugar and free sugar. Additionally, it measured the P. egii ethanol extracts and the total amounts of polyphenol compounds as well as its electron donating ability (EDA) of the substance fraction (SF). The P. eryngii powder's moisture content was 9.0% and each of the other element content such as carbohydrate, crude protein, crude ash and crude fat was found to be 63.06%, 20.70%, 5.20% and 2.0% respectively. Potassium (K) was shown to be the greatest inorganic content and manganese (Mn) was the lowest. Furthermore fructose, galactose, glucose lactose and maltose free sugar content was found in this order. 387 mg% of the total amounts of polyphenol was found in the P. eryngii whole body ethanol extract, 158 mg% in the stipe extract, 593 mg% in the pileus extract and 607 mg% in the substance fraction (SF). Electron donating ability (EDA) was highest at 91.12% in the whole body extract and lowest at 62.90% in the stipe extract. Additionally, the EDA for substance fraction (SF) 0.02%-0.1% was found to be 57.78-77.33%, which was lower than the 0.02%-tocopherol (93.92%) and BHT (96.72%). From these results, it can be assumed that P. eryngii offers superior antioxidative effects with its high content of fiber, inorganic materials and total amounts of polyphenol as well as high electron donating ability (EDA), thereby making it ideal for use in functional foods and industrial materials.

Effects of Various Biodegradable Mulching Films on Growth, Yield, and Soil Environment in Soybean Cultivation (콩 재배지에서 다양한 생분해성 멀칭필름 종류별 작물 생육, 수량 및 토양환경에 미치는 영향)

  • Ye-Guon Kim;Yeon-Hu Woo;Hyun-Hwa Park;Do-Jin Lee;Yong-In Kuk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.69 no.1
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    • pp.34-48
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    • 2024
  • The objective of this study was to evaluate the safety of biodegradable mulching films in soybean (Glycine max) cultivation by measuring their effects on crop growth and yield, film decomposition and soil chemical and physical properties. In 2022 and 2023, plant height, branch number, chlorophyll contents, yield components, and yield of soybean did not vary significantly in areas using PE films and biodegradable mulching films. The light transmission rate of the biodegradable mulching films ranged from 6.4 to 15.8% when measured 112 days after soybean transplanting, and was higher, on average, in 2023 than in 2022. In both years, degradation of the biodegradable mulching films began 20 days after soybean transplantation and increased over time. In addition, remains of biodegradable mulching films were present in fields at soybean harvest and remained until 50 days after harvest. Decomposition rates of the biodegradable mulching films at 112 days after soybean transplanting ranged from 9.8 to 26.7% in 2022 and 13 to 36% in 2023. Although soil pH and EC varied based on the year and timing of measurements, there was no significant difference between areas that used biodegradable mulching films and PE films. Soil organic matter, nitrate and exchangeable cation contents such as Ca, Mg, and K were not significantly different in areas that used both PE films and biodegradable films. However, significantly higher levels of available phosphoric acid content were measured in areas that used biodegradable mulch films E, S, and T. Regardless of which films were used, there were no significant differences in the soil's physical properties. In 2022 and 2023, there was no difference between areas that used biodegradable mulch films and PE films. However, soil temperature in mulched areas was 2℃ higher and soil moisture was 5-15% higher than in non-mulched areas. Barley growth was not affected by being planted in soil that had been used for soybean cultivation with biodegradable films. Therefore, the biodegradable mulch films used in this study can be used without negatively affecting the growth, yield, and soil environment of soybeans.

Seedling - Emergence of Rice, Weedy Rice, and Echinochloa species Sown before Wintering and in the Early Spring (월동전(越冬前) 초춘(初春)에 파종(播種)한 재배(栽培)벼, 잡초성(雜草性)벼 및 피의 출현특성(出現特性))

  • Kwon, Y.W.;Lee, B.W.;Kim, D.S.
    • Korean Journal of Weed Science
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    • v.16 no.2
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    • pp.88-99
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    • 1996
  • In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice

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Dosimetric Effect on Selectable Optimization Parameters of Volumatric Modulated Arc Therapy (선택적 최적화 변수(Selectable Optimization Parameters)에 따른 부피적조절회전방사선치료(VMAT)의 선량학적 영향)

  • Jung, Jae-Yong;Shin, Yong-Joo;Sohn, Seung-Chang;Kim, Yeon-Rae;Min, Jung-Wan;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.23 no.1
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    • pp.15-25
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    • 2012
  • The aim of this study is to evaluate plan quality and dose accuracy for Volumetric Modulated Arc Therapy (VMAT) on the TG-119 and is to investigate the effects on variation of the selectable optimization parameters of VMAT. VMAT treatment planning was implemented on a Varian iX linear accelerator with ARIA record and verify system (Varian Mecical System Palo Alto, CA) and Oncentra MasterPlan treatment planning system (Nucletron BV, Veenendaal, Netherlands). Plan quality and dosimetric accuracy were evaluated by effect of varying a number of arc, gantry spacing and delivery time for the test geometries provided in TG-119. Plan quality for the target and OAR was evaluated by the mean value and the standard deviation of the Dose Volume Histograms (DVHs). The ionization chamber and $Delta^{4PT}$ bi-planar diode array were used for the dose evaluation. For treatment planning evaluation, all structure sets closed to the goals in the case of single arc, except for the C-shape (hard), and all structure sets achieved the goals in the case of dual arc, except for C-shape (hard). For the variation of a number of arc, the simple structure such as a prostate did not have the difference between single arc and dual arc, whereas the complex structure such as a head and neck showed a superior result in the case of dual arc. The dose distribution with gantry spacing of $4^{\circ}$ was shown better plan quality than the gantry spacing of $6^{\circ}$, but was similar results compared with gantry spacing of $2^{\circ}$. For the verification of dose accuracy with single arc and dual arc, the mean value of a relative error between measured and calculated value were within 3% and 4% for point dose and confidence limit values, respectively. For the verification on dose accuracy with the gantry intervals of $2^{\circ}$, $4^{\circ}$ and $6^{\circ}$, the mean values of relative error were within 3% and 5% for point dose and confidence limit values, respectively. In the verification of dose distribution with $Delta^{4PT}$ bi-planar diode array, gamma passing rate was $98.72{\pm}1.52%$ and $98.3{\pm}1.5%$ for single arc and dual arc, respectively. The confidence limit values were within 4%. The smaller the gantry spacing, the more accuracy results were shown. In this study, we performed the VMAT QA based on TG-119 procedure, and demonstrated that all structure sets were satisfied with acceptance criteria. And also, the results for the selective optimization variables informed the importance of selection for the suitable variables according to the clinical cases.

A Study on Serum Lipid Levels in Elderly People in Wando Area - Based on Age, BMI, WHR - (완도지역 성인 및 노인의 혈청지질 수준에 관한 연구(I) - 연령, 신체 계측치를 중심으로 -)

  • Cha, Bok-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.1
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    • pp.68-77
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    • 2006
  • This study was peformed to document the association between nutrient intakes, body mass index (BMI), waist/hip ratio (WHR), and a major risk factor for chronic diseases. A three-day dietary intake survey, using a 24 hour recall method, was obtained from 187 subjects aged 46 to 84 (mean age 65.3) living in Wando island area. The average daily mean energy intakes were 1869.0 kcal for male and 1943.9 kcal for female, respectively. Daily intakes of protein for male and female were 28.0 and 30.4 g, and those of fat were 31.5 and 28.51 g, respectively Carbohydrate dependency was decreased with age. Protein dependency was increased with age. The mean intakes of energy, protein, Vit. A, Vit. D, Vit. E, Ca, Zn did not meet Korean RDA for elderly. The level of serum triglyceride was higher in males than in females and showed the tendency to increase with age in both sexes, whereas HDL-cholesterol tended to decrease with age in both sexes. The levels of serum total-cholesterol and LDL-cholesterol were significantly higher in males than in females, particularly in the age of $46\~59$ (p<0.05). The level of atherogenic index (AI) was significantly higher in females than in males, particularly in the age of 80 and over (p<0.05) Based on these results, it is evident that people in island area did not consume enough nutrient. Specially, dietary intake of protein was not adequate. This study implies that triglyceride, total-cholesterol, LDL-cholesterol, AI were increased with increasing age, BMI and WHR.

Studies on the Meat Production and Woolskin Processing of Sheep and Korean Native Goats for Increasing Farm Income as a Family Subsidiary Work (농가부업(農家副業)의 소득향상(所得向上)을 위한 양육생산(羊肉生産) 및 모피가공(毛皮加工)에 관(關)한 연구(硏究))

  • Kwon, Soon-Ki;Kim, Jong-Woo;Han, Sung-Wook;Lee, Kyu Seung
    • Korean Journal of Agricultural Science
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    • v.5 no.2
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    • pp.93-114
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    • 1978
  • The purpose of the study was to find out possible ways for increasing farm income through the sheep and Korean native goats farming, and to investigate meat productivity, wool productivity; woolskin utility, physiological characteristics and correlation between economical college animal farm of the Chungnam National University and sample farms in the suburbs of Dae jeon City were selected for feeding 20 heads of Corriedale wethers and another 20 heads Korean native kids as research materials for the periods of 5th May-26th November, 1977. The data such as growth rate, carcass, viscera weight, blood picture and plamsa components, hebage intake and economic traits were obtained and analysed. The result of the study are summarized as follows: 1. Meat production and quality 1) After 196days of feeding, the body weight of sheep and Korean native goats was increased by two times of those at the beginning of the trial, i.e. 20kg and 8kg respectively. 2) There was no significance of growth rates of sheep in housing and grazing. 3) The growth rate of Korean native goats were excellent at the mountainous areas of Gong ju-Gun where infectious diseases were not found 4) Accroding to the body measurements of 18-month-old sheep, percentages of hip height, body length, rump length, chest depth, chest width, hip width, chest girth and forearm circumference to the withers height were 103,%, 104%, 33%, 44%, 31%, 23%, 135% and 15% respectively, and those of hip height, body length, chest depth and chest girth of 8-month-old native goats to the withers height were 106%, 109%, 46% and 122,% respecitively. As a result, it was found that the percentage of hip height, body length and chest depth of Korean native goats were higher than those of sheep while that of the chest girth of goats was lower. 5) In the carcass data, 47, $52{\pm}2.27%$ of carcass percentage, $34.61{\pm}1.62%$ of lean meat, $26.07{\pm}2.51%$ of viscera, $9.75{\pm}1.4%$ of bone, and $20.95%{\pm}2.14%$ of woolskin for sheep, and $45.58{\pm}5.63%$ of carcass percentage, $27.62{\p}3.81%$ of meat, $34.86{\pm}4.16%$ of viscera, $11.66{\pm}1.83%$ of bone, $3.63{\pm}1.61%$ of skull and $9.26{\pm}2.41%$ of woolskin for native goats were obtained. 6) The contents of moisture, crude protein, crude fat and crude ash in native goat meat were much similar in both plots of housing and grazing. It was, however, known that the contents of moisture and protein were higher in grazinrg than in housing, while fat content was lower in grazing plots. 7) The weights of visceral organs shown similar tendency for both of sheep and native goats. For the weights of liver, heart, kidney and spleen, significance was not reconized among the treatments. Those of rumen, reticulum, small and large intestine were heavier in grazing than in housing, while the amount of visceral fat was heavier in housing. 2. Wool productivity and woolskin 1) The wool production of sheep for 7 months was $3.88{\pm}1.02kg$, and wool percentage, staple length, straighten length, wool growth per day and number of crimps were $9.27{\pm}1.48%$, 8. $47{\pm}1.00cm$, $10.63{\pm}0.99cm$, $0.40{\pm}0.04cm$ and $2.78{\pm}0.40$ respecitively. 2) The tensile strength and tear strength of woolskin treated by alum tanning were highest on the skin obtained from rump, i.e. $1,351kg/mm^2$ and $2,252kg/mm^2$ respectively, and they are in order of loin and shoulder. 3. Utilization and improvement of pasture. 1) The difference of herbage intake of native goats was not recognized between grazing and tethering, but the intake in the afternoon was s lightly higher than that in the morning. However the hervage intake of sheep was superior in grazing and in the afternoon. 2) The cultivation effect was lower in the native goat plots due to their cultivation abilities, in other words, the establishment rates of pasture by hoof cultivation were 60.25% in the goat plots and 77.35% in the sheep plots. 4. Correlation among economical traits. 1) The correlation between live weight of sheep and daily gain was higher. On the other hand, the correlation between other traits was not significant except that live weight, daily gain and lean meat percentage to the length of thoracic vertebrae. The live weight of native goats and meat production were highly correlated, and high correlation was also found between weights of carcass and meat. However, negative correlation was shown between viscera weight and live weight as well as daily gain. 2) The correlatoin between fleece weight of sheep and other traits such as live weight, daily gain and fleece percentage is very high at the 1% siginficant level, and this means that rapid-growth individuals can produce much fleece. 3) The correlation between the factors such as weights of live body, lean meat and viscera of sheep and body measurements, i. e. chest girth and body length was highest, and weights, of carcass and lean meat was highly correlated to chest width and depth. It will be therefore reasonable that the meat productivity estimates will have to be made on the basis of chest girth and body length. The meat production traits of native goats were highly correlated to the most of body measurement data, and the correlation coefficient between chest girth and weights of live body, carcass, lean meat and bone percentage was very high, i. e. 0.992-0.974 in particular. The correlations of meat production traits to chest depth, forearm circumference, body length were 0.759-0.911, 0.759-0.909 and 0.708-0.872 respectively. Therefore, the meat production of native goats will have to be estimated on the basis of chest data. 5. Blood picture and plasma components. 1) The number of erythrocyte and MCHC of native goats were $12.93{\times}10^6/mm^3$ and 36.14%, and those of sheep were $10.68{\times}10^6/mm^3$ and 36.26 respectively. The values of native goats were significantly higher than those of sheep. 2) The hemoglobin concentration, PVC, MCV and MCR of native goats were 10.92 g/100ml, $23.40{\mu}^3$ and 10.94 pg, and those of sheep were 11.73 g/100ml, 36.25 ml/100ml, $33.97{\mu}^3$ and 30.2 ml/100ml 8.43 pg respectively. The values of native goats were significantly lower those of sheep. 3) The number of leukocytes of native goats was significantly higher than that of sheep, that is, $11.64{\times}10^3/mm^3$ in native goats and $9.32{\times}10^3/mm^3$ in sheep. 4) In differential count of leukocyte, neutrophil was significantly high in native goats while lympocyte in sheep. On the other hand, the basophil, eosinophil and monocyte were not significant between native goats and sheep. 5) The amounts of total protein and glucose in the plasma of native goats were 6.2g/100ml and 53.6mg/100ml, and those of sheep were 5.6g/100ml and 45.7mg/100ml, which means that the values of native goats were significantly higher that those of sheep. The amount of total-lipid of native goats(127.6mg/100ml) was significantly than that of sheep(149.6mg/100ml). 6) The amount of non-protein nitrogen, cholesterol, Ca, P, K, Na and Cl were not different between native goats and sheep. 6. Economic analysis. 1) The gross revenue of a farm which fed native goats and sheep was 4,000won per head and the optimum size for feeding them in a farm as a subsidiary work is 5-10 heads. 2) Since there was no difference between housing and grazing, they can be fed in group for farm's subsidiary work. 3) They can be also fed by youths and house wives in the suburbs of cities, because labour requirement is estimated as only two hours per days for feeding 5 heads of native goats and sheep.

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Limno-Biological Investigation of Lake Ok-Jeong (옥정호의 육수생물학적 연구)

  • SONG Hyung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.1
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    • pp.1-25
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    • 1982
  • Limnological study on the physico-chemical properties and biological characteristics of the Lake Ok-Jeong was made from May 1980 to August 1981. For the planktonic organisms in the lake, species composition, seasonal change and diurnal vertical distribution based on the monthly plankton samples were investigated in conjunction with the physico-chemical properties of the body of water in the lake. Analysis of temperature revealed that there were three distinctive periods in terms of vertical mixing of the water column. During the winter season (November-March) the vertical column was completely mixed, and no temperature gradient was observed. In February temperature of the whole column from the surface to the bottom was $3.5^{\circ}C$, which was the minimum value. With seasonal warming in spring, surface water forms thermoclines at the depth of 0-10 m from April to June. In summer (July-October) the surface mixing layer was deepened to form a strong thermocline at the depth of 15-25 m. At this time surface water reached up to $28.2^{\circ}C$ in August, accompanied by a significant increase in the temperature of bottom layer. Maximum bottom temperature was $r5^{\circ}C$ which occurred in September, thus showing that this lake keeps a significant turbulence Aehgh the hypolimnial layer. As autumn cooling proceeded summer stratification was destroyed from the end of October resulting in vertical mixing. In surface layer seasonal changes of pH were within the range from 6.8 in January to 9.0 in guutuost. Thighest value observed in August was mainly due to the photosynthetic activity of the phytoplankton. In the surface layer DO was always saturated throughout the year. Particularly in winter (January-April) the surface water was oversaturated (Max. 15.2 ppm in March). Vertical variation of DO was not remarkable, and bottom water was fairly well oxygenated. Transparency was closely related to the phytoplankton bloom. The highest value (4.6 m) was recorded in February when the primary production was low. During summer transparency decreased hand the lowest value (0.9 m) was recorded in August. It is mainly due to the dense blooming of gnabaena spiroides var. crassa in the surface layer. A. The amount of inorganic matters (Ca, Mg, Fe) reveals that Lake Ok-Jeong is classified as a soft-water lake. The amount of Cl, $NO_3-N$ and COD in 1981 was slightly higher than those in 1980. Heavy metals (Zn, Cu, Pb, Cd and Hg) were not detectable throughout the study period. During the study period 107 species of planktonic organisms representing 72 genera were identified. They include 12 species of Cyanophyta, 19 species of Bacillariophyta, 23 species of Chlorophyta, 14 species of Protozoa, 29 species of Rotifera, 4 species of Cladocera and 6 species of Copepoda. Bimodal blooming of phytoplankton was observed. A large blooming ($1,504\times10^3\;cells/l$ in October) was observed from July to October; a small blooming was present ($236\times10^3\;cells/l$ in February) from January to April. The dominant phytoplankton species include Melosira granulata, Anabaena spiroides, Asterionella gracillima and Microcystis aeruginota, which were classified into three seasonal groups : summer group, winter group and the whole year group. The sumner group includes Melosira granulate and Anabaena spiroides ; the winter group includes Asterionella gracillima and Synedra acus, S. ulna: the whole year group includes Microtystis aeruginosa and Ankistrodesmus falcatus. It is noted that M. granulate tends to aggregate in the bottom layer from January to August. The dominant zooplankters were Thermocpclops taihokuensis, Difflugia corona, Bosmina longirostris, Bosminopsis deitersi, Keratelle quadrata and Asplanchna priodonta. A single peak of zooplankton growth was observed and maximum zooplankton occurrence was present in July. Diurnal vertical migration was revealed by Microcystis aeruginosa, M. incerta, Anabaena spiroides, Melosira granulata, and Bosmina longirostris. Of these, M. granulata descends to the bottom and forms aggregation after sunset. B. longirostris shows fairly typical nocturnal migration. They ascends to the surface after sunset and disperse in the whole water column during night. Foully one species of fish representing 31 genera were collected. Of these 13 species including Pseudoperilnmpus uyekii and Coreoleuciscus splendidus were indigenous species of Korean inland waters. The indicator species of water quality determination include Microcystis aeruginosa, Melosira granulata, Asterionelta gracillima, Brachionus calyciflorus, Filinia longiseta, Conochiloides natans, Asplanchna priodonta, Difflugia corona, Eudorina elegans, Ceratium hirundinella, Bosmina longirostris, Bosminopsis deitersi, Heliodiaptomus kikuchii and Thermocyclops taihokuensis. These species have been known the indicator groups which are commonly found in the eutrophic lakes. Based on these planktonic indicators Lake Ok-Jeong can be classified into an eutrophic lake.

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A Comparative Study on the Chemical Methods for the Determination of Available Phosphorus in Korean Soils (한국토양(韓國土壤)의 유효인산량(有效燐酸量) 검정(檢定)을 위한 화학적(化學的) 방법(方法)에 대한 연구(硏究))

  • Lim, Sun-Uk;Chung, Jong-Bae;Sa, Tong-Min
    • Applied Biological Chemistry
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    • v.29 no.1
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    • pp.62-72
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    • 1986
  • At present, the definition and chemical analysis method of available soil phosphorus for plants have not been standardized because of the complexity of crop and soil characteristics in Korea and many analysis methods have been suggested with different extraction conditions. Suitable analytical method of available soil P should be established by the trial of various methods based on crop nutrition and soil conditions. To establish the most suitable analysis method of available soiIP, a pot experiment with young maize was conducted over 44 different upland soils collected over the land of Korea. The amount of uptaken P by the plant was determined by ten different chemical methods for the available soil P. The results obtained were as follows: 1. Total phosphorus content in the sample soils ranged ranged $533{\sim}4917\;ppm$, and showed significant positive correlation with the content of organic matter. 2. The P content was relatively low in the acid sulfate soil and very high in the volcanic ash soil although both types of soil contained high level of orgic matter. 3. The amount of extractable P determined by ten different methods were varied more or less, and the ratios of the extractable P to the total soil P were in the range of $1{\sim}48%$. 4. The relative values to the amount of extractable soil P by different methods were in the order of $H_2O(5\;min.)\;1.0\;<\;H_2O(60min.)\;2.27\;<\;NH_4HCO_3\;5.57\;<\;NaHCO_3\;7.42\;<\;Double\;lactate\;9.71\;<\;Bray\;No.1\;12.53\;<\;Lancaster\;17.63\;<\;Nelson\;25.96\;<\;AcOH\;27.6\;<\;CAL-method\;50.27$ 5. The amount of extractable P determined by all of applied methods was very low in acid sulfate soil, volcanic ash soil and coarse textured soil. 6. Soil pH and total soil P generally showed significant positive correlation with the chemically extracted P, and soil organic matter was negatively correlated with the determined by Nelson-and CAL-method. Olsen method which showed significant correlation with exchangeable calcium seemed to be recommendable for calcareous soils. 7. Total amount of uptaken P by Young maize through continuos twice cropping was 4.05% of total soil P in average, and the uptake in the second cropping was twice as much as that of the first cropping. 8. Three determination methods, i.e. Soltanpour-, Double lactate and Bray No. 1-method seemed to be more suitable than Lancaster method which is widely practiced at present in Korea. However, further study should be carried out with other crops and soils to most adequate chemical method for determination of available soil P.

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Prophylactic and therapeutic studies on intestinal giant-cystic disease of the Israel carp caused by Thelophanellus kitauei II. Effects of physical and chemical factors on T. kitauei spores in vitro (향어의 장포자충(Thelohanellus kitauei)증의 예방 및 치료에 관한 기초적 연구 II. 물리화학적 요인이 장포자충 포자에 미치는 영향)

  • Lee, Jae-Gu;Kim, Jong-O;Park, Bae-Geun
    • Parasites, Hosts and Diseases
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    • v.28 no.4
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    • pp.241-252
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    • 1990
  • In a basic attempt to develop the prophylactic and therapeutic measures on intestinal giantcystic disease of the Israel carp, C), prinks carpio nudum, the effects of physical and chemical factors on viability or survival of the spores of Thelchcnellus kiteuei were checked in vitro by means of extrusion test on the polar filament. When the fresh spores suspended with 0.45% and 0.9% scdium chloride solution and distilled water were laid at $5^{\circ}C$ and $28^{\circ}C$ for short terms, the extrusion rates increased until the 3rd day, meanwhile when son;e of them were suspended with Tyrode's solution at $-70^{\circ}C$ the rates increased gradually until the 8th day. Viabilities of the spores suspended with 0.9% saline and added antibiotics to the suspension at $5^{\circ}C$ for long terms lasted for 997 days and 1, 256 days (presumed values) at maximum, respectively. The spores suspended with distilled water at $28^{\circ}C$ for long terms survived 152.4 days, but the spores suspended with Tyrode's solution at $-70^{\circ}C$ for long terms showed almost the same viable pattern as early freezing stages up to 780 days. The spores suspended with Tyrode's solution, frozen at $-70^{\circ}C$ and thawed at $5^{\circ}C$, showed the highest rate of extrusion of the polar filament. In the case of frozen spores, the extrusion rates during heating tend to become higher in accordance with the increase of frozen period, and the critical points of 180 day-frozen spores to be killed were generally 78.5 hr. at $60^{\circ}C$, 23.4 hr. at $70^{\circ}C$, 189.1 min. at $80^{\circ}C$ or 10.5 min. at $90^{\circ}C$. The longer the spores were frozen, the more time was needed for the death of spores after thawing; 20 days-17.4 days, 100 days-33.2 days, and 400 days-37.8 days. The longer the spores were frozen, the more time was needed for the death of spores at a conventional when they were dried air drying condition, 540 days-23.5 days, 160 days-21.0 days, and 20 days-14.4 days. On the other hand, the longer the spores were frozen, the more spores were dead rapidly when they were irradiated with 10W UV-ray; 100 days-26.0 hr, 300 days-21.9 hr, and 540 days-13.9 hr. The time needed for killing 200 days-frozen spores by various disinfectants at 1, 000 ppd was 5.2 min. by calcium oxide, 10.4 min. by potassium permanganate, 27.8 min. by malachite green and 14.3 hr. by formalin. Transient inhibitory effects of the extrusion of the polar filament were observed by various antiprotozoal and antifungal agents in the descending order of ketoconazole. metronidasole and dapsone. The above results presume that full drying, followed by spraying CaO and maintaining sunny condition for a few days on the concrete bottoms of knish farm may be an effective method for the prevention of intestinal giant.cystic disease.

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