• Title/Summary/Keyword: Rate of growth

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Population of Biology of Short-encked clam (Ruditapes philippinarum: Bivalvia) in Kwangyang Bay, Southern Coast of Korea. II. Population Dynamics and Secondary Production (광양만산 바지락(Ruditapes philippinarum: Bivalvia)의 개체군 생물학. II. 성장과 서식환경)

  • 신현출;신상호
    • The Korean Journal of Malacology
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    • v.15 no.1
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    • pp.31-39
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    • 1999
  • This study was aimed to describe the population dynamics and secondary production of Tapes philppinarum on Chohwa and Toksan tidal flats in Kwangyang Bay, from June 1994 to July 1995. The size distributions in shell length showed bimodal patterns from June 1994 to April 1995. Thereafter the distribution changed to the passage of time, indicating an increase in shell length. The mean densities decreased gradually with month. Chohwa A sustained highestdensity, followed by Chohwa B, Toksan C, and Toksan D. The recruitment of new year class occurred first on the upper tidal flat, and then moved to the lower tidal flat. The mean biomass in flesh dry weight of each year class increased in spring just before the spawning period, and thereafter decreased progressively. Annual mean biomass wasrecorded as 170.7 g m$\^$-2/ at Chohwa A, 220.7 g m$\^$-2/ at Chohwa B, 21.8 g m$\^$-2/ at Toksan C, and 45.2 g m$\^$-2/ at toksan D. Annual productions of Ruditapes philippinarum were estimated as 259.72 g m$\^$-2/ yr$\_$-1/ at Chohwa A, 359.79 g m$\^$-2/ yr$\_$-1/ at Chohwa B, 45.02 g m$\^$-2/ yr$\_$-1/ at Toksan c, 68.88 g m$\^$-2/ yr$\_$-1/ at Toksan D. Annual productions were much higher on Chohwa tidal flat than those on Toksan tidal flat. While P:B ratio were higher on Toksan tidal flat as 1.70 than those on Chohwa tidal flat as 1.58. In conclusion, the Chohwa tidal flat showed higher biomass and producion of Ruditapes philippinarum, whereas the Toksan tidal flat showed higher P:B ratio. The total amount of potential food might influence on the density, biomass nad produciton, whereas the amount of food and space per individual might influence on the growth rate and P:B ratio.

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Effect of Slow-release Fertilizer Levels of Rice in Different Cultural Methods (벼 재배양식에 따른 유효성 비료의 시용량이 생육과 수량에 미치는 영향)

  • 정진일;최원영;최민규;이선용
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.6
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    • pp.747-756
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    • 1995
  • To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.

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Effects of Pearl Barley on the Growth and Development of Albino Rats (율무쌀의 경구투여(經口投與)가 백서(白鼠)의 성장(成長)에 미치는 영향(影響))

  • Cho, Soo-Yeul;Park, Myeung-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.6 no.1
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    • pp.41-47
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    • 1977
  • This study was designed to evaluate the nutritive value of pearl barley. Forty males and the same number of females of albino rats, the Leuise strain, weighing from 52.1g to 59.1g were divided into eight experimental groups, five males and females were composed of one group. A group: casein 15%+starch 75%+oil 8%+vitamin mixture 1%+salt mixture 1% B group: pearl barley 98%+vitamin mixture 1%+salt mixture 1% C group: rice 98%+vitamin mixture 1%+salt mixture 1% D group: barley 98%+vitamin mixture 1%+salt mixture 1% E group: rice 49%+pearl barley 49%+vitamin mixture 1%+salt mixture 1% F group: rice 73.5%+pearl barley 24.5%+vitamin mixture 1% +salt mixture 1% G group: barley 49%+pearl barley 49%+vitamin mixture 1% +salt mixture 1% H group: barley 73.5%+Pearl barley 24.5%+vitamin mixture 1%+salt mixture 1% The rats were kept in an individual cage and were fed 8 different diets for 7 weeks and fed by ad-libitum feeding method. The results of this study were eluciated as followings. 1. B group was significantly lower in weight gain than the other groups. 2. Polished pearl barley showed higher digestion rate in protein and carbohydrate than brown pearl barley but lower in fat. 3. Liver weight was obserbed significant differences between B group and C group. but no significant differences between the others. 4. B group was significantly lower in the total protein content of liver and A/G ratio in plasma than other groups. 5. B group was also the lowest in the hematocrit and hemoglobin contents among the experimental groups. 6. Free amino acid composition in plasma was similar to those in diet.

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Single-Dose Oral Toxicity in Rat and Bacterial Reverse Mutation Assay of Psoralea corylifolia L. Extracts (파고지 추출물의 렛트에 대한 단회 경구 투여 독성 및 복귀돌연변이능 평가)

  • Kim, Sun-A;Lim, Sun-Hye;Ahn, Ji-Yun;Kim, Sung-Ran;Ha, Tae-Youl
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.8
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    • pp.960-964
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    • 2007
  • This study was performed to examine the toxicity of Psoralea corylifolia L. by the single-dose oral toxicity tests in rat and bacterial reverse mutation assay. In single-dose oral toxicity tests, 5 mL ethanol extract of P. corylifolia L. were directly injected into 10 rats (5 males and 5 females) at a dosage of 2 g/kg. Death practice was not detected during breeding periods (14 days), and $LD_{50}$ was calculated over 2 g/kg. No difference were observed with control group in the growth rate and histological observations. In bacterial reverse mutation assay, his(-) Salmonella Typhimurium TA98, TA100, TA1535, TA1537 and trp(-) Escherichia coli WP2uvrA (pKM101) were used for assessing the toxicity of ethanol extracts of P. corylifolia L.. No significant difference in formation of the colonies and no dose-dependent increase was observed regardless of the addition of S9 mix. The results showed that ethanol extracts of P. corylifolia L. did not have single-dose oral toxicity and mutagenic toxicity.

A Study on Physical Properties About Velvet Antler of the Elk(Cerus canadensis) (엘크 녹용의 물성 특성에 관한 연구)

  • Sung, S.H.;Han, J.H.;Kim, Y.M.;Kim, B.K.
    • Journal of Animal Environmental Science
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    • v.13 no.3
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    • pp.201-210
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    • 2007
  • In this study, physical properties of Elk antler was investigated to develop the optimum drying and packaging methods for improving the antler quality as well as deal with diversify of demand. After the antler was sliced with 5 mm thickness, and the compressive, shear, and tensile stresses were measured at the center and velvet parts of pre-dried and dried antlers after the contained water rate of the dried antlers was maintained below 10%. The results are as follows. 1. Considering the center of pre-dried antlers, the compressive stresses were $60.73\;g/mm^2$, $145.65\;g/mm^2$, and $260.97\;g/mm^2$, respectively at the upper, middle, and lower parts while $70.67\;g/mm^2$, $811.90\;g/mm^2$, $3,235.52\;g/mm^2$, respectively for velvet layer. Considering the center of dried antlers, the compressive stresses were $190.43\;g/mm^2$, $445.81\;g/mm^2$, and $705.86\;g/mm^2$, respectively at the upper, middle, and lower parts while $734.01\;g/mm^2$, $1,238.40\;g/mm^2$, $4,134.03\;g/mm^2$, respectively for velvet layer. 2. For the pre-dried, the shear stresses were $50.24\;g/mm^2$, $294.44\;g/mm^2$, and $423.47\;g/mm^2$, respectively, and $124.14\;g/mm^2$, $367.69\;g/mm^2$, and $425.86\;g/mm^2$, respectively for the dried antlers. 3. The tensile stresses were $13.59\;g/mm^2$, $62.85\;g/mm^2$, and $112.07\;g/mm^2$, respectively for the pre-dried and $77.24\;g/mm^2$, $175.87\;g/mm^2$, and $184.06\;g/mm^2$, respectively for the dried antlers. 4. In the case of drying antlers, the physical characteristics of the antlers was. changed such as moisture evaporation, contraction, and surface hardening. For the center part, the changes of the physical characteristics were more significant at the lower part while at the upper part for the velvet layer. 5. The stress changes of Elk antlers was shown very remarkably according to growth point. Moreover, the stress was clearly higher at velvet layer part to the center part, base parts compared to the upper parts.

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A New Medium-late Maturity Rice Cultivar, "Hwanggeumnodeul" Suitable for Direct Seeding and with Multiple Disease Resistances (벼 중만생 복합내병 담수직파 및 이앙재배 겸용 신품종 "황금노들")

  • Ko, Jong-Cheol;Kim, Bo-Kyeong;Baeck, Man-Ki;Nam, Jeong-Kwon;Ha, Ki-Yong;Kim, Ki-Young;Ko, Jae-Kwon;Lee, Jae-Kil;Kang, Hyun-Jung;Kim, Young-Doo;Cheong, Jin-Il;Shin, Mun-Sik;Son, Ji-Young;Kim, Woo-Jae;Noh, Gwang-Il;Park, Hyun-Su;Baek, So-Hyeon;Shin, Woon Chul;Kim, Kyeong-Hoon;Shin, Seo Ho;Kim, Chung-Kon
    • Korean Journal of Breeding Science
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    • v.40 no.3
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    • pp.328-331
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    • 2008
  • Hwangeumnodeul is a new japonica rice cultivar developed from a cross between Milyang165 and HR15151-B-21-3 at Honam Agricultural Research Institute (HARI), NICS, RDA, in 2007. This cultivar has short grains and about 139 days of growth duration from direct seeding to harvesting in the southern plain areas. Culm length of this cultivar is 78 cm and the number of spikelet per panicle is similar to that of the check cultivar, Nampyeongbyeo, while filled grain rate is lower than the check variety. This cultivar is moderately resistant to leaf blast, bacterial blight pathogens of $K_1$, $K_2$ and $K_3$ and stripe virus but susceptible to major virus diseases and insect pests. Milled kernel of Hwanggeumnodeul is translucent with non-glutinous endosperm. This cultivar has about 5.7% and 18.6% of protein and amylose contents, respectively. Palatability of cooked rice of Hwanggeumnodeul is similar to Nampyeongbyeo. Its milling recovery and head rice were 75.6% and 90.0%, respectively. Hwanggeumnodeul yielded 5.69 and 5.61 MT/ha in milled rice at the under wet-direct and dry-direct seeding conditions, respectively which are 17% and 12% higher than the check variety, Juanbyeo. It yielded 5.86 MT/ha, 8% higher than Nampyeongbyeo at the standard fertilizer level of the ordinary transplanting cultivation. "Hwanggeumnodeul" would be adaptable for ordinary transplanting as well as direct seeding in the southern plain including Chungcheong province.

Effects of Phenolic Compounds of Persimmon Leaves on Antioxidative System and Miscellaneous Enzyme Activities Related to Liver Function in Ethanol-Induced Hepatotoxicity of Rats (감잎의 Phenolic Compounds가 에탄올을 투여한 흰쥐의 항산화계 및 기타 효소활성에 미치는 영향)

  • 정창주;윤준식;이명렬
    • Food Science and Preservation
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    • v.11 no.1
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    • pp.79-87
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    • 2004
  • To investigate antioxidative effects of phenolic compounds separated from persimmon leaves(PL)(Diospyros kaki Thunb.) on the ethanol-induced hepatotoxicity in rat, Sprague-Dawley rats weighing 100-150 g were divided into 5 groups; control group(CON), PL(70 mg/kg) administered group(PEl), ethanol(5 mL/kg, 25%) administered group(ETH), PL(70 mg/kg) and ethanol administered group (PE2), and PL(140 mg/kg) and ethanol administered group(PE3), respectively. The antioxidative activity of persimmon leaves decreased in order of ethylacetate>interphase materials>n-butanol>chloroform>n-hexane>water fraction. The growth rate and feed efficiency ratio decreased by ethanol were gradually increased to the adjacent level of CON by administering PL. The serum activities of ALT, alkaline phosphatase and lactic acid dehydrogenase elevated by ethanol were decreased significantly. It was also observed that the activities of SOD, catalase, and GSH-Px of rat liver increased by ethanol were markedly decreased in PL administered group as compared to ETH. The GSH content of liver was decreased by ethanol, but that was increased in PE1 and PE2 compared with ETH as a dose-dependant manner. These results suggested that phenolic compounds separated from persimmon leaves have a possible protective and relievable effect on the ethanol-induced hepatotoxicity in rats.

Application of Greenhouse Climate Management Model for Educational Simulation Design (교육용 시뮬레이션 설계를 위한 온실 환경 제어 모델의 활용)

  • Yoon, Seungri;Kim, Dongpil;Hwang, Inha;Kim, Jin Hyun;Shin, Minju;Bang, Ji Wong;Jeong, Ho Jeong
    • Journal of Bio-Environment Control
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    • v.31 no.4
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    • pp.485-496
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    • 2022
  • Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO2 enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

Biochemical Methane Potential Analysis of Mushroom Waste Medium (버섯 폐배지의 생화학적 메탄퍼텐셜 분석)

  • Kim, Chang-Gyu;Lee, Jun-Hyeong;Yoon, Young-Man
    • Journal of the Korea Organic Resources Recycling Association
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    • v.30 no.1
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    • pp.13-21
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    • 2022
  • Mushroom waste medium refers to the waste biomass generated after mushroom cultivating. And, the burden of treatment on mushroom farmhouse is increasing due to the absence of appropriate treatment method and increase of treatment costs of the mushroom waste medium. In this study, in order to assess the energy value of mushroom waste medium by an anaerobic digestion, methane potential and anaerobic organic matter decomposition characteristics were investigated. The theoretical methane potential(Bth) of mushroom medium(MM) was 0.481 Nm3-CH4/kg-VSadded, and the Bth of mushroom waste medium(MWM) was 0.451 Nm3-CH4/kg-VSadded. The biochemical methane potential(Bu-exp) of MWM was increased by 18% from 0.155 for MM to 0.183 Nm3-CH4/kg-VSadded for MWM. In the reaction kinetics analysis by the Modified Gompertz model, the maximum methane production rate(Rm) was increased from 4.59 for MM to 7.21 mL/day for MWM and the lag growth phase time(λ) was decreased from 2.78 for MM to 1.96 days for MWM. In the reaction kinetics analysis by the parallel first order kinetics model, the easily degradable organic matter(VSe) content was increased by 5.89% and the persistently degradable organic matter(VSp) content was 2.03% in MWM, and the non-degradable organic matter(VSNB) content was decreased by 7.85%. Therefore, it was evaluated that the anaerobic digestion efficiency of MWM was increased. The anaerobic digestion efficiency of MWM was assessed to be more improved than that of MM.

Monitoring of Plant Community Structure Change for Four Years(2007~2010) after Riparian Ecological Restoration, Nakdonggang(River) (낙동강 수변 생태복원지 시공 후 4년간(2007~2010년) 식생구조 변화 모니터링)

  • Ki, Kyong-Seok;Kim, Jong-Yup
    • Korean Journal of Environment and Ecology
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    • v.26 no.5
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    • pp.707-718
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    • 2012
  • This study was conducted to monitor 4 years of changes in the vegetation structure starting from 2007 when restoration began and propose vegetation management ideas for the riparian ecological restoration areas in the purchased land around Nakdonggang(River). The study was conducted in each of 15 locations ($208,342m^2$) in the riparian ecological restoration areas in November 2007, September 2008, October 2009 and September 2010. The analysis results of the changes in planting species and population showed that, in the case of trees, Acer pseudo-sieboldianum, Quercus acutissima, Acer ginnala, Quercus aliena, Quercus variabilis indicated relatively little changes in their numbers and Quercus dentata, Cornus walteri, Morus alba, Styrax obassia, Sorbus alnifolia var. macrophylla indicated a 100% withering rate. Most shrubs withered due to the oppressive pressure of herbs and climbing plants. The planting density decreased over 4 years on average 28 plants/$100m^2$ to 20 plants/$100m^2$ to 16 plants/$100m^2$. Shortly after the restoration, The the amount of growth was reduced by restoration stress. however as time goes on after the restoration tended to stabilize. The changes in the basal area showed a decrease from $507.1cm^2/100m^2$ in 2007 right after restoration to $301.8cm^2/100m^2$ in 2008 and afterwards showed an increasing trend by going to $324.9cm^2/100m^2$ in 2009 and $372.7cm^2/100m^2$ in 2010. To improve the planting structure of the riparian ecological restoration area, the selection of tree species that have been considered for soil moisture and the differentiation of suitable planting structures that have been considered for local conditions were needed.