• Title/Summary/Keyword: Delayed potential

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Study on Forage Cropping System Using Summer Forage Crops with Italian Ryegrass at Paddy Land of Gangjin Region in South Korea (남부지역 논에서 이탈리안 라이그라스와 하계 사료작물을 연계한 작부체계에 관한 연구)

  • Jeong Sung Jung;Se Young Lee;Mirae Oh;Hyung Soo Park;Ana Yun;Ki Choon Choi
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.43 no.1
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    • pp.35-41
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    • 2023
  • This experiment was carried out to examine double cropping system using Italian ryegrass (IRG) 'Kowinearly', whole crop rice 'Yeongwoo' and barnyard millet 'Jeju native' during the Oct. 2020 to Oct. 2022. Three kinds of forage crops were cultivated at paddy field in Livestock Institute, Jeollanamdo Agricultural Research and Extension Services, Jeollanamdo, South Korea. Whole crop rice (WCR) was sown in late May and barnyard millet (BM) sown early June each year after harvesting IRG. We examined dry matter yield and feed value of forage crops depending on harvest time of forage crops during the experimental period. The plant height in heading stage of IRG ranged from 108 to 112cm and dry matter yield ranged from 6,783 to 11,530 kg ha-1. The crude protein (CP) of IRG ranged from 6.0 to 8.44%, acid detergent fiber (ADF) ranged from 55.6 to 60.2% and neutral detergent fiber (NDF) ranged from 32.58 to 36.7%, The dry matter yield of WCR increased as the harvest stage was delayed (14,310 kg ha-1 in milk, 16,167 kg ha-1 in yellow ripen, and 18,891 kg ha-1 in mature). Similar to results of dry matter yield of WCR, dry matter yield of BM increased as the harvest stage was delayed (11,194 kg ha-1 in late heading. and 14,308 kg ha-1 in mature), However nutrient content of WCR and BM showed a decreasing trend. As shown in above results, the productivity of WCR after harvesting IRG was shown to be high at paddy field in the southern region. However, BM also was appeared to have potential as summer forage crops.

An Agrometeorological Reference Index for Projecting Weather-Related Crop Risk under Climate Change Scenario (농작물의 기상재해 발생위험 판정기준 설정 및 지구 온난화에 따른 기준기상위험의 변화 전망)

  • Kim, Dae-jun;Kim, Jin-hee;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.3
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    • pp.162-169
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    • 2016
  • The agrometeorological reference index means 'the agrometeorological damage possibility' or the possibility of the normal year climate condition to damage the crop cultivation in a certain region. It is a reference used to compare the cultivation risk of a crop by region. The global climate warming is expected to increase the winter temperature. At the same time, the frequency of extreme weather events will also increase. Therefore, people pay attention to the potential of low temperature-induced damages (e.g., frost damage and injury) to fruit trees under the future climate condition. However, simple damage projection based on climate conditions does not help the climate change adaptation in the practical aspect because the climate change affects the phenology of fruit trees as well. This study predicted the phenology of the pear, peach, and apple trees by using the climate change scenarios of major regions. Furthermore, low temperature induced agrometeorological reference indices were calculated based on the effects of temperature on each plant growth stage to predict the damage possibility. It was predicted that the breaking rest would delay more in the future while the bud-burst date and flowering date will be earlier. In Daegu, Jeonju, and Mokpo, the breaking rest delayed more as time passed. The bud-burst date and flowering date of Seoul and Incheon regions were later than other regions. Seoul and Incheon showed a similar pattern, while Daegu and Jeonju revealed a similar pattern. Busan and Mokpo also showed a similar pattern. All regions were safe from the frost damage during the dormancy period. However, plants were vulnerable to frost damage between the breaking rest and the bud-burst period. Regions showed different frost damage patterns between the bud-burst period and the flowering period. During the bud-burst and flowering period, the risk level decreased in general, although the risk of some areas tended to increase.

An Analysis on the Over-Potentially Deposited Hydrogen at the Polycrystalline $Ir/H_2SO_4$ Aqueous Electrolyte Interface Using the Phase-Shift Method (위상이동 방법에 의한 다결정 $Ir/H_2SO_4$ 수성 전해질 계면에서 과전위 수소흡착에 관한 해석)

  • Chun Jagn Ho;Mun Kyeong Hyeon
    • Journal of the Korean Electrochemical Society
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    • v.3 no.2
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    • pp.109-114
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    • 2000
  • The relation between the phase-shift profile fur the intermediate frequencies and the Langmuir adsorption isotherm at the poly-Ir/0.1 M $H_2SO_4$ aqueous electrolyte interface has been studied using ac impedance measurements, i.e., the phase-shift methods. The simplified interfacial equivalent circuit consists of the serial connection of the electrolyte resistance $(R_s)$, the faradaic resistance $(R_F)$, and the equivalent circuit element $(C_P)$ of the adsorption pseudoca-pacitance $(C_\phi)$. The comparison of the change rates of the $\Delta(-\phi)/{\Delta}E\;and\;\Delta{\theta}/{\Delta}E$ are represented. The delayed phase shift $(\phi)$ depends on both the cathode potential (E) and frequency (f), and is given by $\phi=tan^{-1}[1/2{\pi}f(R_s+R_F)C_P]$. The phase-shift profile $(-\phi\;vs.\;E)$ for the intermediate frequency (ca. 1 Hz) can be used as an experimental method to determine the Langmuir adsorption isotherm $(\theta\;vs.\;E)$. The equilibrium constant (K) for H adsorption and the standard free energy $({\Delta}G_{ads})$ of H adsorption at the poly-Ir/0.1 M $H_2SO_4$ electrolyte interface are $2.0\times10^{-4}$ and 21.1kJ/mol, respectively. The H adsorption is attributed to the over-potentially deposited hydrogen (OPD H).

SPONTANEOUS ERUPTION GUIDANCE OF UNERUPTED TOOTH AFTER SURGICAL REMOVAL OF COMPLEX ODONTOMA (복잡 치아종의 외과적 적출후 미맹출치의 자발적 맹출 유도)

  • Park, Sung-Youn;Nam, Dong-Woo;Kim, Hyun-Jung;Kim, Young-Jin;Nam, Soon-Hyeun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.489-494
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    • 2003
  • Odontomas are the common type of odontogenic tumors and generally they are asymptomatic, depending upon size, location and their limited growth potential. they are rarely diagnosed before the second decade of life, and the frequently lead to impaction or delayed eruption of permanent teeth. Odontomas are classified of compound as compound or complex by morphology. Complex odontomas are unorganized masses of odontogenic tissues, morphologically not resembling the teeth, account for approximately 25 percent of all odontomas, 22 percent of odontogenic tumor of the jaws, and have a predilection for the posterior mandible in males. The etiology of odontomas is unknown, although local trauma, infection, and genetic factors have been suggested. Usually, treatment of odontoma is conservative sugical removal and their is little probability of recurrence. This paper describes two cases of complex odontomas diagnosed in children due to impaction of maxillary first molar in all cases, the surgical excision of the lesions was performed. Follow-up after 2 years, showed spontaneous eruption of the first permanent molar to the occlusal plane.

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The Relation between the Phase-Shift Profile for the Intermediate Frequencies and the Langmuir Adsorption Isotherm (중간주파수에서 위상이동 변화와 Langmuir흡착등온식 사이의 관계)

  • Chun Jang Ho;Mun Kyeong Hyeon;Cho Chong Dug
    • Journal of the Korean Electrochemical Society
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    • v.3 no.1
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    • pp.25-30
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    • 2000
  • The relation between the phase-shift profile for the intermediate frequencies and the Langmuir adsorption isotherm at the poly-$Pt/0.1\;M\;H_2SO_4$ aqueous electrolyte interface has been studied using ac impedance measurements, i.e., the phase-shift methods. The suggested interfacial equivalent circuit consists of the serial connection of the electrolyte resistance ($R_S$), the faradaic resistance $(R_F)$ and the equivalent circuit element $(C_P)$ of the adsorption pseudocapacitance $(C_\varphi)$. The delayed phase shift $(\varphi)$ depends on both the cathode potential (E) and frequency (f), and is given by $\varphi=-tan^{-1}[1/2{\pi}f(R_s+R_F)C_p]$. The phase-shift profile $(\varphi\;vs.\;E)$ for the intermediate frequency (ca. 6Hz) can be used as an experimental method to determine the Langmuir adsorption isotherm (9 vs. E). The equilibrium constant (K) for H adsorption and the standard free energy $({\Delta}G_{ads})$ of H adsorption at the poly-$Pt/0.1\;M\;H_2SO_4$ electrolyte interface are $1.8\times10^{-4}\;and\;21.4kJ/mol$, respectively. The H adsorption is attributed to the over-potentially deposited hydrogen (OPD H).

Endogenous Nitric Oxide Strengthens Doxorubicin-induced Apoptosis in Human Colorectal Cell Lines (Doxorubicin에 의한 내인성 산화질소가 인간 대장암 세포주에서의 세포사멸에 미치는 효과)

  • Im, Soon Jae;Kim, Ji Hye;Kim, Min Young
    • Journal of Life Science
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    • v.24 no.10
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    • pp.1137-1143
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    • 2014
  • Doxorubicin is a general chemotherapy drug widely used for a number of cancers. However, the correlation between endogenous nitric oxide ($NO^{\bullet}$) levels and chemoresistance to doxorubicin remains unclear. In this study, we investigated the effect of endogenous $NO^{\bullet}$ on the anticancer activity of doxorubicin in human colon cancer cell lines HCT116 and HT29 with different p53 status. The cells were treated with either doxorubicin alone or in combination with the $NO^{\bullet}$ synthase (NOS) inhibitor $N^G$-monomethyl-L-arginine (NMA). Doxorubicin differentially inhibited the growth of both the HCT116 (p53-WT) and HT29 (p53-MUT) cells, which was mitigated by cotreatment with NMA. Further studies revealed that inhibition of endogenous $NO^{\bullet}$ mitigated doxorubicin-induced apoptosis in the HCT116 and HT29 cells, as evidenced by apoptotic DNA fragmentation and the sub-G1 peak of apoptotic markers. Apoptosis was delayed in the HT29 cells, and its magnitude was greatly reduced, underscoring the importance of the modulation of p53 in the response. RT-PCR analysis revealed that doxorubicin down-regulated levels of inhibitors of the apoptosis family (cellular IAP-1 and-2). Collectively, these data show that induction of apoptosis by doxorubicin in human colon cancer cells is possibly related to modulation of endogenous $NO^{\bullet}$, the expression of the IAP family of genes, and the status of p53. The underlying mechanisms may represent potential targets for adjuvant strategies to improve the efficacy of chemotherapy for colon cancer.

Mathematical Modeling of the Novel Influenza A (H1N1) Virus and Evaluation of the Epidemic Response Strategies in the Republic of Korea (수학적 모델을 이용한 신종인플루엔자 환자 예측 및 대응 전략 평가)

  • Suh, Min-A;Lee, Jee-Hyun;Chi, Hye-Jin;Kim, Young-Keun;Kang, Dae-Yong;Hur, Nam-Wook;Ha, Kyung-Hwa;Lee, Dong-Han;Kim, Chang-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.43 no.2
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    • pp.109-116
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    • 2010
  • Objectives: The pandemic of novel influenza A (H1N1) virus has required decision-makers to act in the face of the substantial uncertainties. In this study, we evaluated the potential impact of the pandemic response strategies in the Republic of Korea using a mathematical model. Methods: We developed a deterministic model of a pandemic (H1N1) 2009 in a structured population using the demographic data from the Korean population and the epidemiological feature of the pandemic (H1N1) 2009. To estimate the parameter values for the deterministic model, we used the available data from the previous studies on pandemic influenza. The pandemic response strategies of the Republic of Korea for novel influenza A (H1N1) virus such as school closure, mass vaccination (70% of population in 30 days), and a policy for anti-viral drug (treatment or prophylaxis) were applied to the deterministic model. Results: The effect of two-week school closure on the attack rate was low regardless of the timing of the intervention. The earlier vaccination showed the effect of greater delays in reaching the peak of outbreaks. When it was no vaccination, vaccination at initiation of outbreak, vaccination 90 days after the initiation of outbreak and vaccination at the epidemic peak point, the total number of clinical cases for 400 days were 20.8 million, 4.4 million, 4.7 million and 12.6 million, respectively. The pandemic response strategies of the Republic of Korea delayed the peak of outbreaks (about 40 days) and decreased the number of cumulative clinical cases (8 million). Conclusions: Rapid vaccination was the most important factor to control the spread of pandemic influenza, and the response strategies of the Republic of Korea were shown to delay the spread of pandemic influenza in this deterministic model.

A Study on the Restoration Priority Decision Model of Oil Contaminated Military Sites (유류로 오염된 군사기지의 복원 우선순위 결정 모델 연구)

  • Roh, Kyung-Hee;Yang, Im-Suk;Han, Uk
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.05a
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    • pp.59-63
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    • 2000
  • At military bases, environmental restoration activities resulting from oil contamination are growing concerns of preventing adverse effects on human health and environments. Its technologies are still under developing stage through some countries such as United States and Germany. This study is focused on developing model for a decision-maker to assist the restoration priority under the situation of limited resources such as budget and time. The Model, named the Base Restoration Priority Decision model(BRP model), is composed of the three factors : oil contaminants receptors, and the potential migration pathways. Each risk rating of factor is combined in the 27 matrix blocks and set immediate, moderate, and delayed action category designated restoration priority. This is categorized to group sites into three degree using the simplest of assessment system. As a result, the model will be able to apply to the effective allocation of resources for the restoration by any decision-maker because the model is easy to understand. Also, the continuous study will have established risk assessment system for the restoration of contaminated military with this study as the starting point.

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Estimation of Annual Runway Capacity for Jeju International Airport Considering Aircraft Delays (항공기 지연시간을 고려한 제주국제공항 활주로 연간용량 산정)

  • Park, Jisuk;Yun, Seokjae;Lee, Youngjong;Baik, Hojong
    • Journal of Korean Society of Transportation
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    • v.33 no.2
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    • pp.214-222
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    • 2015
  • Jeju International Airport has become the most delayed airport in Korea, due to increased demand in air passengers and unexpected local weather condition. Observing the demands continuously grow for a decade, the airport is expected to be saturated in the near future. As a part of effort to prepare effective and timely measure for this expected situation, airport planners seeks the annual runway capacity, i.e., the appropriate number of flight operations in a given year with tolerable delay. In practice, the FAA formula is frequently adopted for the capacity estimation. The method, however, has intrinsic issues: 1) the hourly capacity imbedded in the formula is not clearly defined and thus the estimated value is vulnerable to be subjective judgement, and 2) the formula doesn't consider aircraft delay resulted from runway congestion. In this paper, we explain a novel method for estimating the daily runway capacity and then converting to the annual capacity taking into account the aircraft delay. In this paper, average delay of aircraft was measured using microscopic air traffic simulation model. Daily capacity of the runways were analyzed based on the simulation outputs and the method to assess the yearly capacity is introduced. Using a microscopic simulation model named TAAM, we measure the average aircraft delay at various levels of flight demand, and then estimate the practical daily runway capacity. The estimated daily and annual runway capacities of Jeju airport are about 460 operations a day which is equal to 169,000 operations year. The paper discusses how to verify the simulation model, and also suggests potential enhancement of the method.

Changes of Cytosolic $Ca^{2+}$ under Metabolic Inhibition in Isolated Rat Ventricular Myocytes

  • Kang, Sung-Hyun;Kim, Na-Ri;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Warda, Mohamed;Kim, Hyung-Kyu;Von Cuong, Dang;Kim, Tae-Ho;Kim, Eui-Yong;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.5
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    • pp.291-298
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    • 2005
  • To characterize cytosolic $Ca^{2+}$ fluctuations under metabolic inhibition, rat ventricular myocytes were exposed to $200{\mu}M$ 2,4-dinitrophenol (DNP), and mitochondrial $Ca^{2+}$, mitochondrial membrane potential (${\Delta}{\Psi}m$), and cytosolic $Ca^{2+}$ were measured, using Rhod-2 AM, TMRE, and Fluo-4 AM fluorescent dyes, respectively, by Laser Scanning Confocal Microscopy (LSCM). Furthermore, the role of sarcolemmal $Na^+$/$Ca^{2+}$ exchange (NCX) in cytosolic $Ca^{2+}$ efflux was studied in KB-R7943 and $Na^+$-free normal Tyrode's solution (143 mM LiCl ). When DNP was applied to cells loaded with Fluo-4 AM, Fluo-4 AM fluorescence intensity initially increased by $70{\pm}10$% within $70{\pm}10$ s, and later by $400{\pm}200$% at $850{\pm}45$ s. Fluorescence intensity of both Rhod-2 AM and TMRE were initially decreased by DNP, coincident with the initial increase of Fluo-4 AM fluorescence intensity. When sarcoplasmic reticulum (SR) $Ca^{2+}$ was depleted by $1{\mu}M thapsigargin plus $10{\mu}M ryanodine, the initial increase of Fluo-4 AM fluorescence intensity was unaffected, however, the subsequent progressive increase was abolished. KB-R7943 delayed both the first and the second phases of cytosolic $Ca^{2+}$ overload, while $Na^+$-free solution accelerated the second. The above results suggest that: 1) the initial rise in cytosolic $Ca^{2+}$ under DNP results from mitochondrial depolarization; 2) the secondary increase is caused by progressive $Ca^{2+}$ release from SR; 3) NCX plays an important role in transient cytosolic $Ca^{2+}$ shifts under metabolic inhibition with DNP.