• Journal of Chest Surgery
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• v.20 no.4
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• pp.673-682
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• 1987

The principal feature of bioprosthetic valve which remains to be completely defined is long-term durability, especially, with regard to the impact of patient age. This report provides extended data regarding valve durability derived from a data base of 515 patients who received lonescu-Shiley bioprosthetic valve between 1978 and 1985; cumulative duration of follow-up was 1562.3 patient-years, with a maximum follow-up duration of 8.7 years. The results of this survey showed as follows: 1] The actuarial freedom from valve failure at 6 years were 43*7% for 0-19 year-old group, 70*1% for 20-39 year-old group and 75*1% for over 40 year-old group separately. 2] Of the causes of valve failure, only the primary tissue failure was markedly influenced by patient`s age [p<0.001], but the prosthetic valve endocarditis was not [p>0.1]. 3] The linealized incidences of primary tissue failure were 7.31% per patient-year in 0-19 year-old group and 0.12% in 20-39 year-old group. 4] The primary tissue failure rate in 0-19 year-old group was 6.36% during first 4 years, but then increased upto 10.95% at postoperative 5 year. Thus we find that in bioprosthetic valve the primary tissue failure is apt to occur when patient is young [especially less than 20 years old] and the postreplacement time passes [especially over 5 years]. The rate of bioprosthesis failure among children and adolescents is clearly higher than that observed in adult patients; however, conclusive quantification of time-related risk for young patient is not yet possible on the basis of existing data. Therefore, the advisability of bioprosthesis implantation in children remains to be determined.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1137-1143
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• 2011

Optimum soil management of chestnut orchards is important to ensure high quality and yields of chestnut. This study was conducted to evaluate soil and green leaf characteristics by establishment periods of chestnut (Castanea crenata Sieb. et. Zucc.) orchards in Sancheong-gun, Gyeongsangnam-do. Total 30 plots with the criteria of similar cultivation practices were chosen and classified into two establishment periods by over 20-year-old orchards (17 plots) and below 19-year-old orchards (13 plots). Soil bulk density was significantly higher (p<0.05) in over 20-year-old ($1.16g\;cm^{-3}$) than in below 19-year-old ($1.03g\;cm^{-3}$) plots. Soils in over 20-year-old plots were severely acidified with pH 4.56 compared to pH 4.73 in below 19-year-old plots. However, soil organic matter, total nitrogen, available phosphorus, and potassium were not significantly different (p>0.05) between both establishment periods. Leaf area, leaf mass, and nutrient (N, P, K, Ca, Mg) concentration of green leaves were also not significantly different (p>0.05) between both establishment periods. The results indicate that soil bulk density in chestnut orchards is dependent on the establishment periods, while soil chemical property and leaf nutrient concentration may be little influenced by the establishment periods.

• The Korean Journal of Ecology
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• v.2 no.1
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• pp.9-14
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• 1978

The study was made to expand the knowledge of the ecology of Cobitis koreensis which is very common in the upper and middle part of rivers in western part of Korea. A number of C. koreensis are found in the creek of Jeonju-cheon located at Segjang-ri, Wanju-gun, Jeonrabug-do Province. The area studied has pebble bottoms. The flow velocity of the river ranges from 20cm to 40cm per second under normal conditions. The sex ratio of male to female was 1:1.34 and the female was 10~25mm larger than the male in total length. Length-frequencies in this population indicate that 20~40 mm fish group is underyearling, 40~60mm is a yearling, and 60~85mm is two-year-old. And the fish longer than 90mm in total length is regarded as being over three-year-old. Based on the ratio of gonadal weight to body weight, spawning in this species began in April and expanded well into June with water temperature 20~26。C, and the individuals became sexually mature over the two-year-old. The number of the eggs was counted from ten matured female fishes. The mean number of eggs in seven 72.6~81.4mm fishes was 908 (595-1, 229) and that of the rest three 86.0~89.0mm was 1, 674 (1, 337-2, 023). The contents of stomach in the other fifteen specimens captured in September 1977 were investigated. While the younger fed almost on the algae, the foods in the adult were largely aquatic insects.

• Journal of Agricultural Extension & Community Development
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• v.6 no.1
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• pp.25-34
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• 1999

This study was aimed 1) to determine the job-stress level of agricultural extension ants, 2).to analyze job-stress and its related variables. Data were collected from 512 extension ants who work at agricultural technology center in Pusan and Kyungnam province, 462 subjects were analyzed. SAS program was used. The major findings of this study were as follows: 1) the score of job-stress was low and that of job satisfaction was high,; 2) the degree of role overload of 40 year-old agents who have worked for over 20 years was high,; 3) the degree of role ambiguity of 20 year-old who have worked below 15 years was high,; 4) the degree of job-stress perception of 40 year-old agents was high,; 5) the degree of job satisfaction of among agents who finished graduate course and who are charge of section was high.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.227-235
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• 2006

Changes of the species diversity and development of vegetation structure during abandoned field succession after shifting cultivation were investigated in Pyoungchang, Gangwon-Do, Korea. The height of top layer tended to increase rapidly during the earlier successional stages and stabilize in the later successional stage. The heights of top layer in the 10, 20, 50 and 80 year old-field were 4, 9, 18 and 18 m, respectively. In this region, thirty five year after abandonment need for the development to the normal forest formed by 4 stratum structure, tree, sub-tree, shrub and herb layer. Among the vegetation values, Ivc showed a tendency to increase logarithmically, and Hcl a tendency to increase linearly during abandoned field succession. Species diversity showed the peak in mid-successional stages ($10{\sim}20$ year old-field) and declined slightly thereafter. Species diversity was correlated closely with the species richness than the evenness. The most woody species established in the earlier stage ($2{\sim}6$ year old-field) and turned over their dominance step by step during succession. These results support the IFC model proposed by Egler (1954).

• Journal of Chest Surgery
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• v.14 no.1
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• pp.17-25
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• 1981

In 1980, 416 cases of open heart surgery were done in this Department with over all operative mortality of 12.3%. 1. There were 288 congenital anomalies consisting of 174 acyanotic and 114 cyanotic varieties, which showed operative mortality of 6.9% and 25.4% respectively. 2. There were 128 cases of acquired lesions, 124 valvular disease and 3 myxoma being the main lesions. 3. There were 128 cases of valve replacement with operative mortality of 7.8%. 4. The most frequently operated anomaly was VSD, 90 pure VSD and 21 cases were associated with one or 2 cardiac anomalies. Over all operative mortality in 111 VSD cases was 8.1% but in 90 pure VSD cases it was 6.7%. 5. Tetralogy of Fallot showed the highest incidence in cyanotic group with 88 cases, consisting of 68 pure and 20 with other cardiac anomalies. Over all mortality in 88 cases was 19.3% but in pure form 16.2%. 6. In 128 valve replacement cases over all mortality was 9.4%. There were 85 mitral, 11 aortic, 2 tricuspid, 21 mitral with aortic, 6 mitral with tricuspid, 3 mitral, aortic, and tricuspid valve replacement cases. For mitral valve replacement operative mortality was 5.9%. 7. Twenty-one cases of babies under 10kg body weight were operated on with over all operative mortality of 28.6%. Sixteen cases of VSD were found with operative mortality of 25%. 8. Among 128 cases of valve replacement 7 were under the age of 15 years and 12 were between 15 and 20 years old. Five pediatric cases underwent mitral valve replacement without mortality, 9 year old boy was the youngest among them. In this Department open heart surgery for infancy and complex anomalies showed still hip operative risk which should be improved in the coming years. For open heart surgery Shiley oxygenators and 2 sets of A-O de-lux 5 head roller pump were utilized exclusively. For valve replacement Ionescu-Shiley bovine pericardial xenografts were mainly used. In pediatric and rural patients Persantin with aspirin regimen was satisfactorily administered for anticoagulation after valve replacement. Routinely Coumadin was administered for one year after valve replacement* In patients who had thrombus on valve sites, chronic atrial fibrillation, and giant left atrium Persantin-Aspirin regimen was used when one year coumadin administration was discontinued.

• The Korean Journal of Community Living Science
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• v.19 no.4
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• pp.569-580
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• 2008

The purpose of this study is to investigate opposites acquisition and tendency of processing negations about directional oppositionality from 3- to 6-old Korean children. The data were collected from 80 children from a daycare center and 20 university students in Busan, Korea. In Experiment 1, participants were asked to produce opposites for common terms related to colors, directions, and dimension adjectives. In Experiment 2, they were asked to make pictures corresponding to statements with negations(e. g. The arrow is NOT pointing up.). Summarizing the overall results, first, children over 5 considered 'blue' and 'red' as opposites colors in the case of not well-known color opposites. If there exists an opposite color, color opposites have been acquired from 6 year-olds, the directional opposites started from 3 year-olds, and the opposites of dimension adjectives did from 5 year-olds. Second, preferring the antipodal color opposites started from 6 and preferring the antipodal direction did from 3. Consequently, 3-to 6 year-old children acquired opposites at different age and opposites dimension. Also the opposites dimension have an effect on processing negation of young children.

• Journal of environmental and Sanitary engineering
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• v.21 no.2 s.60
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• pp.47-56
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• 2006

This study was to investigate relationship between osteoporosis and various factors. We compared the result in 390 women with under -2.5 bone mineral density (BMD, T-scores) with those in 370 women with over -1.0 BMD. According to WHO criteria, women with -2.5 BMD are regarded as patient with osteoporosis, while with above -1.0 BMD are healthy. We obtained the BMD(T-scores) data of 9.704 adult women over 20 year old. The following are the results of this study: The mean age of interviewed women was 45.7 years and their menopausal age was 48.6 years. Means of height and weight were 157.3cm and 56.9Kg respectively. The BMD was the highest in 30-34 year-old women, an average ranges were in the 35-44 year old group. The BMD decreased after 45 year-old. The early sixties women began to experience thiness of the BMD and the mid-sixties showed symptoms of osteoporosis. The formular showing the relationship between age and BMD can be represented as $Y=9.71X^2-2.71X+0.06$ (p<0.001). The bone mineral density decreased significantly with increases of age(p<0.001) and decreases of weight(p<0.001) in multiple regression analysis using age, weight, menopause age, height, number of pregnancies, number of children, and age as independent variables.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.145-172
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• 1984

In order to assess the physical growth pattern of Korean Youth, the authors measured the body height, body weight, chestgirth and sitting height of 40967 persons (24832 males and 16135 females) from primary schools, middle and high schools and colleges of metropolitan (urban) and rural areas, and calculated the mene, standard deviation, standard error and coefficient variance of the body weight chestgirth, sitting height and various pertinent index by body height to demonstrate the standard physical growth and development by body height of sex and age. The following conclusions were obtained. 1. Physical growth and development: Rapid growth of physical growth in terms of body height has been observed among males in the age $7{\sim}15$ and among female $7{\sim}13$. Growth in terms of body height turned out to be slower among students of higher age by both sexes. The age of cross over between to sexes is between 10 to 13 years where upon girls out grows boys. Maximum annual growth were upon girls out grows boys. Maximum annual growth were both of 6.16cm from 8 to 9 years old and 12 to 13 years old for boys and 7.2cm from 8 to 9 and 6.1cm from 9 to 10 for girls. This indicates that girls enter a rapidly growing stage 2 years earlier than boys. Meanwhile, prominent improvement in body height of national students over period of ten year was noticed. 2. The distribution status of body height by age: The distribution status of body height by age were as follows; 7 year of age: boys-30cm range of body height from 104.0cm to 133.9cm, girls-27cm from 104.0cm to 130.9cm 8 year of age: boys-30cm from 116.0 to 145.9cm girls-33cm from 113.0 to 145.9cm 9 year of age: boys-30cm from 116.0 to 145.9cm girls-33cm from 113.0 to 145.9cm 10 year of age: boys-39cm from 116.0 to 154.9cm girls-39cm from 119.0 to 157.9cm 11 year of age: boys-45cm from 119.0 to 163.9cm girls-39cm from 122.0 to 160.9cm 12 year of age: boys-45cm from 125.0 to 169.9cm girls-42cm from 125.0 to 166.9cm 13 year of age: boys-45cm from 128.0 to 172.9cm girls-42cm from 128.0 to 169.9cm 14 year of age: boys-48cm from 131.0 to 178.9cm girls-36cm from 134.0 to 169.9cm 15 year of age: boys-42cm from 137.0 to 181.9cm girls-33cm from 137.0 to 169.9cm 16 year of age: boys-39cm from 146.0 to 184.9cm girls-30cm from 143.0 to 172.9cm 17 year of age: boys-39cm from 146.0 to 184.9cm girls-27cm from 143.0 to 169.9cm 18 year of age: boys-36cm from 152.0 to 187.9cm girls-27cm from 146.0 to 172.9cm 19 year of age: boys-30cm from 155.0 to 184.9cm girls-24cm from 146.0 to 169.9cm 20 year of age: boys-24cm from 158.0 to 181.9cm girls-l8cm from 149.0 to 166.9cm 3. Standard values of body weight, chest-girth and sitting height by body height of age were found all age groups from 7 to 20 years old and listed in tables from3-a to 16-a. 4. Standard values of relative body weight, relative chestgirth and relative sitting height by body height of age were found all age groups from 7 to 20 years old and listed in tables from 3-b to 16-b. 5. Standard values of physical and nutritional indices (Rohrer index, Kaup index, Vervaeck index and Pelidisi index) by body height of age were found all age groups from 7 to 20 years old and listed in tables from 3-c to 16-c.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.548-565
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• 2023

Armillaria root disease affects forests around the world. It occurs in many habitats and causes losses in the infested stands. Weather conditions are important factors for growth and development of Armillaria species. Yet, the relation between occurrence of damage caused by Armillaria disease and weather variables are still poorly understood. Thus, we used generalized linear mixed models to determine the relationship between weather conditions of current and previous year (temperature, precipitation and their deviation from long-term averages, air humidity and soil temperature) and the incidence of Armillaria-induced damage in young (up to 20 years old) and older (over 20 years old) coniferous stands in selected forest districts across Poland. We used unique data, gathered over the course of 23 years (1987-2009) on tree damage incidence from Armillaria root disease and meteorological parameters from the 24-year period (1986-2009) to reflect the dynamics of damage occurrence and weather conditions. Weather parameters were better predictors of damage caused by Armillaria disease in younger stands than in older ones. The strongest predictor was soil temperature, especially that of the previous year growing season and the current year spring. We found that temperature and precipitation of different seasons in previous year had more pronounced effect on the young stand area affected by Armillaria. Each stand's age class was characterized by a different set of meteorological parameters that explained the area of disease occurrence. Moreover, forest district was included in all models and thus, was an important variable in explaining the stand area affected by Armillaria.