• Title/Summary/Keyword: Kangwon National University

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Changes in Flora Dynamics on the Reclaimed Tidal Flats of Kyonggi-Bay in the Mid-west Coast of Korea (우리나라 중서부 해안 경기만 간척지에서 식생변화)

  • Kim, Eun-Kyu;Jung, Yeong-Sang;Chun, Soul;Joo, Young-K.;Jeong, Hyeung-Geun
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.4
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    • pp.289-300
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    • 2009
  • Flora distribution was surveyed in the newly reclaimed tidal flats in the west coastal area in Korea to understand changes in flora dynamics after reclamation. The surveyed reclaimed tidal flats were the newly reclaimed tidal flat in Hangdam, the mid Kyonggi Bay in 2002, and three reclaimed lands in Seukmun and Daeho, Chungnam, and Hangdam in Kyonggi Bay, of which reclamation years based on embankment were 7, 9 and 18 years, respectively. In the newly reclaimed tidal flat, the dominant flora was Suaeda japonica and other florae were rare, while various halophytes and glycophytes were distributed in the reclaimed lands. On the newly reclaimed tidal flat, four species of halophytic pioneer florae, Salicornia europaea, Suaeda glauca, Suaeda japonica, and Suaeda maritime occurred, and along with age facultative halophyte and glycophyte occurred sequently. On the reclaimed lands, the florae were more complex with various facultative halophyte and glycophyte, so these were predominated rather than pioneer halophyte, while one of pioneer halophyte that Suaeda japonica was not occurred. Increasing of various facultative halophyte and glycophyte, and decreasing of pioneer halophyte indicated that flora changed toward to increase of facultative halophyte and glycophyte by aged after reclamation. On the newly reclaimed tidal flat the ratio of flora species changed rapidly with the invasion of plant. This implied that the flora had begun to change in the early stage of reclamation. Facultative halophyte and glycophyte started to increase on the early stage of reclamation but relative density and frequency of pioneer halophyte was higher than facultative halophyte and glycophyte. According to the investigation up to 3 years after reclamation, pioneer halophyte predominated on it. Although flora changed, there were common representative halophytes among the reclaimed tidal flats: Salicornia europaea, Suaeda maritima, and Suaeda glauca as pioneer halophyte, Aster tripolium, Sonchus brachyotus, and Phragmites communis as facultative halophytes.

Growth kinetics and chlorine resistance of heterotrophic bacteria isolated from young biofilms formed on a model drinking water distribution system (모델 상수관망에 형성된 초기 생물막에서 분리한 종속영양세균의 생장 동역학 및 염소 내성)

  • Park, Se-Keun;Kim, Yeong-Kwan;Oh, Young-Sook;Choi, Sung-Chan
    • Korean Journal of Microbiology
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    • v.51 no.4
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    • pp.355-363
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    • 2015
  • The present work quantified the growth of young biofilm in a model distribution system that was fed with chlorinated drinking water at a hydraulic retention time of 2 h. Bacterial biofilms grew on the surface of polyvinyl chloride (PVC) slides at a specific growth rate of $0.14{\pm}0.09day^{-1}$ for total bacteria and $0.16{\pm}0.08day^{-1}$ for heterotrophic bacteria, reaching $3.1{\times}10^4cells/cm^2$ and $6.6{\times}10^3CFU/cm^2$ after 10 days, respectively. The specific growth rates of biofilm-forming bacteria were found to be much higher than those of bulk-phase bacteria, suggesting that biofilm bacteria account for a major part of the bacterial production in this model system. Biofilm isolates exhibited characteristic kinetic properties, as determined by ${\mu}_{max}$ and $K_S$ values using the Monod model, in a defined growth medium containing various amounts of acetate. The lowest ${\mu}_{max}$ value was observed in bacterial species belonging to the genus Methylobacterium, and their slow growth seemed to confer high resistance to chlorine treatment (0.5 mg/L for 10 min). $K_S$ values (inversely related to substrate affinity) of Sphingomonas were two orders of magnitude lower for acetate carbon than those of other isolates. The Sphingomonas isolates may have obligate-oligotrophic characteristics, since the lower $K_S$ values allow them to thrive under nutrient-deficient conditions. These results provide a better understanding and control of multi-species bacterial biofilms that develop within days in a drinking water distribution system.

An Evaluation of the Use of Statistical Methods in the Journal of Tuberculosis and Respiratory Diseases ([결핵 및 호흡기질환] 게재 논문의 통계적 기법 활용에 대한 평가)

  • Koh, Won-Jung;Lee, Seung-Joon;Kang, Min Jong;Lee, Hun Jae
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.2
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    • pp.168-179
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    • 2004
  • Background : The statistical analysis is an essential procedure ensuring that the results of researches are based on evidences rather than opinion. The purpose of this study is to evaluate which statistical techniques are used and whether these statistical methods are used appropriately or not in the journal of Tuberculosis and Respiratory Diseases. Materials and Methods : We reviewed 185 articles reported in the journal of Tuberculosis and Respiratory Diseases in 1999. We evaluated the validity of used statistical methods based upon the checklist that was developed on the basis of the guideline for statistical reporting in articles for medical journals by International Committee of Medical Journal Editors. Results : Among 185 articles, original articles and case reports were 110 (59.5%) and 61 (33.0%) respectively. In 112 articles excluding case reports and reviews, statistical techniques were used in 107 articles (95.5%). In 94 articles (83.9%) descriptive and inferential methods were used, while in 13 (11.6%) articles only descriptive methods were used. With the types of inferential statistical techniques, comparison of means was most commonly used (64/94, 68.1%), followed by contingency table (43/94, 45.7%) and correlation or regression (18/94, 19.1%). Among the articles in which descriptive methods were used, 83.2% (89/107) showed inappropriate central tendency and dispersion. In the articles in which inferential methods were used, improper methods were applied in 88.8% (79/89) and the most frequent misuse of statistical methods was inappropriate use of parametric methods (35/89, 39.3%). Only 14 articles (13.1%) were satisfactory in utilization of statistical methodology. Conclusion : Most of the statistical errors found in the journal were misuses of statistical methods related to basic statistics. This study suggests that researchers should be more careful when they describe and apply statistical methods and more extensive statistical refereeing system would be needed.

Effect of Various Composition of Nutrient Solution on Growth and Yield of Strawberry 'Maehyang' in Coir Substatrate Hydroponics (다양한 배양액 조성이 코이어 수경재배 딸기 '매향'의 생육과 수량에 미치는 영향)

  • Lee, Jeong Hun;Lee, Yong-Beom;Choi, Ki Young
    • Journal of Bio-Environment Control
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    • v.26 no.3
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    • pp.227-234
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    • 2017
  • This study aimed to investigate the nutrient solution developed by based on nutrient-water absorption rate of strawberry 'Maehyang' by comparing growth and yield for 8 months with 5 kinds of nutrient solution with different ion composition. Strawberry plants were planted at elevated bed and supplied with five kinds of nutrient solutions (RDA), Yamazaki, PBG, University of Seoul (UOS) and NewUOS from one month onwards. Five types of nutrient solution were supplied to the strawberry plants associated with EC $1.0dS{\cdot}m^{-1}$, pH 6.0, $150{\sim}300mL{\cdot}plant^{-1}$ per day. At 60 days after planting, leaf width and leaf petiole of the strawberry plants showed significant differences among nutrient solution types and photosynthesis was higher in RDA and NewUOS nutrient solution and lower in PBG nutrient solution. The EC of the drainage on vegetative growth stage was $0.7{\sim}0.8dS{\cdot}m^{-1}$, which is lower than the supplied EC level, and to $1.0-1.2dS{\cdot}m^{-1}$, afterwards. The pH of the drainage was higher in Yamzaki solution as 6.2~6.8, while the pH of the UOS nutrient solution was lower in 5.1~5.2. Nitrate content was most absorbed in vegetative growth stage and after flower clusters development. The potassium uptake was highest at the NewUOS followed by UOS and Yamazaki nutrient solution. At six months after -planting fresh weight and dry weight of shoot and root were higher in UOS and NewUOS nutrient solution than other nutrient solutions, and the dry matter ratio was lower at 43.5% in Yamazaki nutrient solution and 30.6% in NewUOS nutrient solution than other solutions. Length, width, weight, and sugar content of the strawberries harvested from December to February were unaffected by treatment, but yield was higher in NewUOS nutrient solution due to increasing fruit number and average weight. From March to May, number of fruit was higher in Yamazaki nutrient solution. In conclusion, there was no difference in the growth of 'Maehyang' when 5 nutrient solutions were grown under hydroponics. But in order to improve the marketability, the NewUOS nutrient solution is appropriate to use from planting to February and it is suitable to use Yamazaki nutrient solution after March when temperature is high and the amount of fruit set per inflorescence.

Angiographic Results of Radial Artery Grafts that are Used for Myocardial Revascularization (관상동맥 우회술 후 혈관조영술을 이용한 요골동맥의 개통률 분석)

  • Yie, Kil-Soo;Oh, Sam-Sae;Kim, Jae-Hyun;Shinn, Sung-Ho;Kim, Soo-Cheol;Seo, Hong-Joo;Na, Chan-Young
    • Journal of Chest Surgery
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    • v.40 no.8
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    • pp.546-551
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    • 2007
  • Background: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other gratis with retrospective manner. Material and Method: From January 2001 to Jure 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month ($2{\sim}110$ month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. Result: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p < 0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. Conclusion: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

Quality Changes of Cherry Tomato with Different Chlorine Dioxide ($ClO_2$) Gas Treatments during Storage (저장 중 이산화염소 가스의 처리 조건에 따른 방울토마토의 품질변화)

  • Choi, Woo Suk;Ahn, Byung Joon;Kim, Young Shik;Kang, Ho-Min;Lee, Jung-Soo;Lee, Youn Suk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.19 no.1
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    • pp.17-27
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    • 2013
  • The effects of chlorine dioxide gas ($ClO_2$) treatments between high-concentration-short-time and low-concentration-long-time on maintaining the quality of cherry tomatoes (Lycopersicon esculentum Mill. cv 'unicorn') were investigated. Tomatoes were treated with 5 ppm for 10 min and 10 ppm for 3 min as high-concentration-short-time $ClO_2$ gas treatment conditions and 1 ppm for once a day interval in terms of low-concentration-long-time $ClO_2$ gas treatment condition, respectively. After $ClO_2$ gas treatments, tomatoes were storage at 5 and $23^{\circ}C$ for 7 days. Weight loss, changes in tomato color, firmness, soluble solids content, pH, growth of total microorganism, and decay rate were evaluated. On day 7, tomatoes treated with chlorine dioxide gas showed low values of respiratory rate, total microbial growth, and decay rate compared to those of tomato without chlorine dioxide gas treatment. Additionally, tomatoes treated the chlorine dioxide were kept the values of firmness and soluble solids content during storage. However, chlorine dioxide gas treatment on tomatoes had no direct effect on weight loss, pH, and color. Results showed that both $ClO_2$ concentration and treatment time played the important roles for keeping the quality of tomatoes during storage. Tomatoes with chlorine dioxide gas treatment of low-concentration-long-time had more effective values of firmness, the total microbial growth, and decay rate than those with two chlorine dioxide gas treatments of high-concentration-short-time. Results suggest the potential use of chlorine dioxide gas treatment of low-concentration-long-time as an highly effective method for keeping the freshness of cherry tomato.

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Effects of Alcoholic Feeds on In vitro Ruminal pH, Ammonia, Alcohol and Volatile Fatty Acids Concentrations (Alcohol 사료가 In vitro 반추위내 pH, Ammonia, Alcohol 및 Volatile Fatty Acids 농도에 미치는 영향)

  • 신종서;박병기
    • Journal of Animal Science and Technology
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    • v.48 no.1
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    • pp.91-100
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    • 2006
  • In this study, changes of ammonia, alcohol and volatile fatty acid(VFA) concentrations or pH in in vitro ruminal fluid were studied to determine the effects of alcoholic feeds on in vitro ruminal fermentation characteristics. To formulate the alcoholic feeds, alcohol was added to commercial formulated feed at the levels of 1, 3, and 5 %. Experiments were done with four treatment groups, control(commercial feed), AF-1(commercial feed+1% alcohol), AF-3(commercial feed+3% alcohol), and AF-5(commercial feed+5% alcohol). Ammonia concentrations of AF-1 and AF-5 were significantly lower than that of control for the 12h incubation(p<0.05). Ruminal alcohol concentration was increased with the addition level of alcohol increased(p<0.05). TVFA concentrations of AF-1, AF-3 and AF-5 were significantly higher than those of control at 12h(p<0.05). Significant decrease of molar percentage of acetate was observed in control from 8 to 12h incubation, but molar percentage of acetate for AF-1, AF-3 and AF-5 was constant. Molar percentage of propionate was increased in control compared with AF-1, AF-3 and AF-5 from 8 to 12h incubation(p<0.05). Molar percentages of butyrate and valerate were higher in AF-1, AF-3 and AF-5 than in control(p<0.05). Molar percentage of caproate for AF-1, AF-3 and AF-5 was 0.05, 0.58 and 0.47M% at 8h, respectively, but that was not detected for control. Present results may indicate that the alcoholic feeds show positive effects on in vitro ruminal ammonia, alcohol and VFA concentrations or pH. Furthermore, the results of this study implies that the addition level of 5% could be more effective to ruminal fermentation than other addition levels.

The Legal Status of Military Aircraft in the High Seas

  • Kim, Han Taek
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.1
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    • pp.201-224
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    • 2017
  • The main subject of this article focused on the legal status of the military aircraft in the high seas. For this the legal status of the military aircraft, the freedom of overflight, the right of hot pursuit, the right of visit and Air Defense Identification Zone (ADIZ) were dealt. The 1944 Chicago Convention neither explicitly nor implicitly negated the customary norms affecting the legal status of military aircraft as initially codified within the 1919 Paris Convention. So the status of military aircraft was not redefined with the Chicago Convention and remains, as stated in the 1919 Paris Convention, as a norm of customary international law. The analyses on the legal status of the military aircraft in the high seas are found as follows; According to the Article 95 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS) warships on the high seas have complete immunity from the jurisdiction of any State other than the flag State. We can suppose that the military aircraft in the high seas have also complete immunity from the jurisdiction of any State other than the flag State. According to the Article 111 (5) of the UNCLOS the right of hot pursuit may be exercised only by warships or military aircraft, or other ships or aircraft clearly marked and identifiable as being on government service and authorized to that effect. We can conclude that the right of hot pursuit may be exercised by military aircraft. According to the Article 110 of the UNCLOS a warship which encounters on the high seas a foreign ship, is not justified in boarding it unless there is reasonable ground for suspecting that: (a) the ship is engaged in piracy, (b) the ship is engaged in the slave trade, (c) the ship is engaged in an unauthorized broadcasting and the flag State of the warship has jurisdiction under article 109, (d) the ship is without nationality, or (e) though flying a foreign flag or refusing to show its flag, the ship is, in reality, of the same nationality as the warship. These provisions apply mutatis mutandis to military aircraft. As for Air Defence Identification Zone (ADIZ) it is established and declared unilaterally by the air force of a state for the national security. However, there are no articles dealing with it in the 1944 Chicago Convention and there are no international standards to recognize or prohibit the establishment of ADIZs. ADIZ is not interpreted as the expansion of territorial airspace.

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Biological Activities of Solvent Extracts from Leaves of Aceriphyllum rossii (돌단풍 잎 용매추출물의 생리활성)

  • Lim, Sang-Hyun;Kim, Hee-Yeon;Park, Min-Hee;Park, Yu-Hwa;Ham, Hun-Ju;Lee, Ki-Yun;Kim, Kyung-Hee;Park, Dong-Sik;Kim, Song-Mun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.12
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    • pp.1739-1744
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    • 2010
  • In this study, the bioactivities of ethanol (EEAR) and water extract (WEAR) from the leaf of Aceriphyllum rossii were investigated. In the anti-oxidative activity, IC50 of DPPH radical scavenging activity was respectively 549.86 and $62.14{\mu}g$/mL by EEAR and WEAR. Anti-inflammatory activity of EEAR and WEAR has been evaluated on inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) release by the macrophage RAW 264.7 cells. EEAR and WEAR inhibited inflammatory by 5.58 and 16.85% in 10 mg/mL, respectively. In the anti-diabetic activity, $IC_{50}$ of $\alpha$-glucosidase inhibitory activity was 5.62 and $425.63{\mu}g$/mL by EEAR and WEAR. $IC_{50}$ of $\alpha$-amylase inhibitory activity of EEAR and WEAR was 4,623.87 and over $10,000{\mu}g$/mL, respectively. In the anti-obesity, all lipase inhibitory activity ($IC_{50}$) of EEAR and WEAR was up $10,000{\mu}g$/mL. Finally, EEAR and WEAR exhibited anti-oxidative and anti-diabetic activity. It suggests that Aceriphyllum rossii could be potentially used as a resource of bioactive materials for health functional foods.

Effect of Aceriphyllum rossii Ethanol Extract on Lipid Metabolism in Rats Fed a High-Fat Diet (돌단풍 에탄올 추출물이 고지방식이를 급여한 흰쥐의 지질대사에 미치는 영향)

  • Park, Yu-Hwa;Kim, Hee-Yeon;Lim, Sang-Hyun;Kim, Kyung-Hee;Park, Dong-Sik;Lee, Jung-Hoon;Park, Chung-Geon;Park, Chung-Berm;Kim, Song-Mun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.10
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    • pp.1411-1416
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    • 2011
  • In this study, we investigated the anti-obesity activity of Aceriphyllum rossii ethanol extract on rat fed a high fat diet. Male SD rats were divided into four groups. Group 1 was the control. Group 2 was fed a high-fat diet. Group 3 was the positive control, fed a high-fat diet supplemented with Garcinia Cambogia extracts. Group 4 was fed a high fat diet supplemented with ethanol extracts of Aceriphyllum rossii (EEAR). Precisely 166 mg/kg of powdered Garcinia Cambogia extracts was used for Group 3. Also, 250 mg/kg of EEAR was used for Group 4. The Body weight increased Group 2, but decreased Group 4. The serum total cholesterol in Group 2 increased by 15.26% when compared to Group 1, but only increased 5.29% in Group 3 and 4.29% in Group 4. The liver and mesenteric adipose tissue weights of Group 2 increased compared to Group 1, whereas they decreased in Group 3 and Group 4. As a result of measuring the concentration of triglycerides in extracted livers, Group 2 showed a significant increase compared to the Group 1, and Groups 3 and 4 showed significant decrease compared Group 2. These results suggest that Aceriphyllum rossii ethanol extracts may be useful as an anti-obesity agent.