• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.684-696
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• 1995

A mutant for chalky endosperm and genetic male sterility (GMS) was newly developed in rice. The two characters were found to be controlled by single recessive gene which has pleiotropic effect, indicating that chalky seeds should be GMS seeds in segregating populations. Chalky seeds showed the same shape and size as normal seeds. However, starch composition of central part of endosperm was looser and shape of starch granules was rounder compared with normal endosperm, resulting in significantly lower grain weight, absolute density and grain hardness in chalky grains than in normal ones. Amylose content and gel consistency of chalky grains were much lower and harder, respectively. Male sterile plants showed much shorter plant height, poorer panicle exsertion and lesser panicle number compared with normal plants. Microspore abortion stage in pollen developmental process was observed as before meiosis. Male sterility of the mutant was stable regadless of temperature and day length. A system breeding hybrid rice using this mutant was discussed, comp ring with other systems utilizing cytoplasmic-genic male sterility(CGMS) and environment sensitive GMS(EGMS). Separation of GMS seeds in mixed seed bulks by specific gravity (1.14∼1.16g / cm3) was successful about 85∼90%. But some mixed normal plants were seemed to be easily removed by the apparent difference in growth characters at seedling stage. The highest natural outcrossing rate of this GMS line was as 17.3 % in a plot treated with 2-row pollinator, I-row GMS, and GA3 + cutting of flag leaf + pollen-scattering by rope.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.593-606
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• 2005

Present study was conducted to investigate the optimal feeding levels for producing the high quality meat on the basis of the information deriving from the comparison of the growth performance and carcass characteristics among breeds(Holstein vs F1, Holstein♀×Hanwoo♂), sex(steer vs heifer) and interaction between breed and sex. Thirty two animals on 4 treatments(i.e. eight head each) were used for 540 days from seven to 24 months of age. The results obtained are summarized as follows; the range of average daily gains was 0.733 to 1.018, 0.994 to 1.255, 0.947 to 1.259 and 0.736 to 0.824kg for the growing, the early-fattening, the mid- fattening and the finishing periods, respectively. The range of average daily gains for the entire period was 0.882 to 1.061kg. The gains were higher for Holstein(7.3%) and the steers(10.5%) than F1 and the heifers, respectively. Concentrates and total digestible nutrients intakes per kg gain were higher for Holstein and the heifers than F1 and the steers, respectively. These findings may indicate that feed utilization is higher for Holstein than F1, and higher for the steers than the heifers. In carcass characteristics, back fat thickness was thicker for Holstein than F1, and rib-eye area was smaller for Holstein than F1. The rib-eye area per kg carcass weight was larger for F1 and the heifers than Holstein and the steers, respectively. Meat color was better for Holstein than F1, but the sex distinction did not show any differences. In physicochemical properties of longissimus dorsi, shear force, cooking loss, water holding capacity and the panel test scores of juiciness, tenderness and flavor for F1 and the heifers were better than those for Holstein and the steers, respectively. According to the above results, we may conclude that F1 and heifers rather than Holstein and steers are recommended for high quality meat production. In steers and heifers of Holstein and F1, the optimal feeding levels may be 1.9% of apparent body weight for concentrates and 25% of concentrates intake for rice straw.

• Korean Journal of Poultry Science
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• v.8 no.2
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• pp.69-75
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• 1981

The experiment was carried out to observe whether the route of administration of allantoic aminiotic fluid obtained from the chicken embryo infected with $B_1$ virus would affect the protectivity of brids against the challenge exposure of a virulent strain of ND virus. Four groups of birds of 30 days of age were immunized intranassally (0.1 $m\ell$), intramuscularly (1.0 $m\ell$), by spray administration (0.00015 $m\ell$/1㎤) or via drinking water(10.0 $m\ell$), with 1 in 100 dilution of th. fluid containing $B_1$ virus titre of 10$\^$8.5/ELD$\_$50/ per $m\ell$ and all the immunized birds, after 15 days of vaccination, were challenged intramuscularly with 1.0$m\ell$ of 10,000 MLD per $m\ell$ of a virulent ND virus. The results obtained are summerized as follows: 1. Good immunity was induced when 1 in 100 dilution of allantoaminiotic fluid with $B_1$ virus titre of 10$\^$8.5/ELD$\_$50/$m\ell$was applied to 30 day old chicks intramuscularly, intranasally and by spray application, but it was not the case when the allantomiotic fluid was diluted to 1 in 1,000. The ID$\_$50/ of birds immunized with 1 in 100 dilution of allantoaminiotic fluid by various routes of administration such as intramuscular Injection, spray application and intranasal instillation were 10$\^$2.8/＞10$\^$4.l and/＞10$\^$4.2/ 2. The high protectivity against the challenge exposure with a virulent Newcastle disease virus with 10,000 MLD/$m\ell$ were observed when the birds were immunized with a live vaccine of 10$\^$8.5/ ELD$\_$50/$m\ell$ by intramuscular injection, intranasal instillation or spray application, and the rates by different routes of application were 92.62%, 95.33% and 93.75%, respectively. On the contrary, no good immunity was induced in the groups of birds immunized via drinking water with the live vaccine, the rate of protection against the challenge exposure being 47.18%.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.151-160
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• 2006

This study was conducted to investigate the genetic characteristics of growth stages in Hanwoo, to provide useful information in farm management decisions. Data were taken from the nucleus herds of three farms, Namwon, Daegwalyong and Seosan, comprising 27,647 cows, 14,744 bulls, and 1,290 steers in between 1980 and 2004. According to the growth curve by year, the residuals for cows and bulls were 68.49 and 54.29, respectively, under the Gompertz model. The values were lower than in other years. Parameters, A, b and k were estimated as 423.6±5.8, 2.387±0.064 and 0.0908±0.0033 in cows and 823.3±15.3, 3.584±0.070, 0.1139±0.0032 in bulls, respectively. The fitness was higher under the Gompertz model than under the logistic model: monthly and daily estimation for cows were 379.3±7.509, 2.499±0.057, 0.114±0.0045 and 367.1±1.9003, 2.3983±0.012, 0.004±0.00003, respectively. Estimated residual mean squares were 31.85 and 998.4 in their respective models. Monthly and daily estimation of bulls were 834.6±22.00, 3.319±0.062, 0.104±0.0037 and 796.0±6.128, 3.184±0.014, 0.003±0.00003, respectively. Estimated residual mean square were 66.18 and 2106.5. Monthly and daily estimation of steers were 1049.1±144.2, 3.024±0.008, 0.067±0.0096 and 1505.1±176.6, 2.997±0.067, 0.001±0.0001, relatively. Squares, 186.0 and 1119.1. In terms of growth characteristic estimated by Gompertz model, body weight for cows and bulls were 139.53kg and 307.03kg, and the daily gains were 0.52kg and 1.04kg, respectively. Body weight for steers was 385.94kg at the inflection point. Body weight gain was 0.84kg in both models. Our results showed that cows had lower mature weight and daily weight gain, and reached the inflection point earlier than bulls or steers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.2
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• pp.87-95
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• 2017

The increase in the frequency of occurrence of abnormal weather could include severe rainfall, which could cause rice submergence during the ripening stage. This experiment was conducted to clarify the effects of submergence during the ripening period on yield and quality of rice. The flooding treatment was conducted at 7 and 14 days after heading. Flooding conditions were created with two conditions, flag leaf exposed and overhead flooding, and each condition was divided into two conditions according to water quality-clear and muddy. Although the yield decrease was more severe at 7 days after heading because of the decrease in the ripening ratio, the head rice ratio was more affected at 14 days after heading because of the increase in the chalky kernel ratio. The maximum quantum yield (Fv/Fm), which indicates the photosynthetic efficiency, did not differ before and after the flooding treatment until flooding continued for 4 days. In addition, stem elongation occurred because of flooding as an avoidance mechanism in japonica rice. This phenomenon was expected to decrease the supply of assimilation products to the spikelet (sink). Overall, it was suggested that additional experiments should be conducted examining the change in the starch synthesis mechanism and transfer of assimilate products resulting from submergence, for development of cultivation techniques corresponding to submergence and breeding of varieties with submergence tolerance characteristics.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.540-548
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• 2000

The aim of this study was to evaluate the timing of sequence of tooth calcification in current Korean growing children. The Calcification stage of permanent teeth of Korean children was investigated by classifying them into 10 stages by the criteria of Nolla, using the panoramic radiographs of 258 healthy Korean children, 149 males and 109 females, between the ages of 4 years and 13 years, with normal growing tendency and no orthodontic treatment experience. The obtained results were as follows: 1. Timing of calcification of permanent teeth by Nolla stage was established with mean values. Among the mean value, results of Nolla stage 7 were as follows: Calcification timing of male in the maxilla was 6 year 9 month on central incisor, 7 year 4 month on lateral incisor,7 year 9 month on canine, 8 year 8 month on the first premolar, 9 year 4 month on the second premolar, 6 years 3 month on the first molar and 10 year 8 month on the second molar, calcification timing of male in the mandible was 5 year 11 month on central incisor, 6 year 4 month on lateral incisor, 7 year 5 month on canine, 8 year 1 month on the first premolar, 8 year 6 month on the second premolar 5 years 6 month on the first molar and 10 year 3 month on the second molar. Calcification timing of female in the maxilla was 6 year 2 month on central incisor, 6 year 7 month on lateral incisor, 6 year 11 month on canine, 8 year 1 month on the first premolar, 8 year 5 month on the second premolar, 5 years 10 month on the first molar and 9 year 10 month on the second molar, calcification timing of male in the mandible was 5 year 6 month on central incisor, 5 year 9 month on lateral incisor, 6 year 8 month on canine, 7 year 6 month on the first premolar, 8 year 4 month on the second premolar, 5 years 3 month on the first molar and 9 year 7 month on the second molar. 2. The sequence of calcification at Nolla stage 7 was in consequence to the first molar, central incisor, lateral incisor, canine, the first premolar, the second premolar and second molar. 3. While the sequence of root completion of maxilla was in consequence to the first molar, central incisor, lateral incisor, that of mandible was in order of central incisor, first molar and lateral incisor. 4 the calcification timing of permanent teeth was earlier in female than in male (p<0.05). According to above data, the result of this study is applicable for diagnosis and routine clinical practice for children.

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1058-1059
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• 2003

학동기(만 6-12세)에 좋은 영양 공급은 일생의 성장 발육의 기초를 조성하여 지적, 사회적, 정서적 능력을 향상시킬 수 있다. 이에 초등학생의 영양문제와 식습관을 해결하는 방안의 하나로 최근 대두되고 있는 아침결식률을 낮추기 위한 ‘아침 안 거르기’ 사업을 학교와 연계 개발하여 프로그램을 진행하고 그 효과를 평가하였다. 이 연구는 서울시 강북구 관내에 위치한 4개 초등학교 5학년 학생 1026명(실험군 451명, 대조군 675명)을 대상으로 4∼9월까지 6개월간 5단계로 실시되었다. 프로그램의 효과평가를 위해 사전(실험군-학생 428명, 부모 416명, 대조군-학생 656명, 부모 589명), 사후(실험군-학생 427명, 부모 368명, 대조군-학생 608명, 부모 558명) 설문조사를 2회 실시하여 행동과 인식률 변화를 측정하였다. 프로그램은 매월 1회 담임교사가 진행하였고, 교육자료 및 홍보물은 아침먹기 캐릭터 가방걸이와 학부모의 참여를 높이고자 가정통신문과 교육내용을 함께 삽입하여 제작한 알림장, 아침먹기와 일찍자기를 실천할 실천스티커를 배포하였고 프로그램 종료 후 아침 먹기 실천달력을 제공하였다. 또 아동들 자신의 식생활을 바르게 꾸려 나갈 수 있도록 가공식품의 ‘영양표시’에 관한 교육을 함께 교육하였고, 설문조사를 통해 영양표시제에 관한 인식변화와 행동변화율을 측정하였다. 학생들의 아침식사 실천율은 매일 먹는 그룹이 실험군은 62.9%에서 69.6%로 7% 상승하였고, 전혀 먹지 않는 그룹은 11.2%에서 6.4%로 4.8% 감소하였다(p<0.001) 대조군의 경우 매일 먹는 그룹은 70.4%에서 70.2%로, 전혀 먹지 않는 그룹은 6.9%에서 6.5%로 나타났다(p<0.001). 아침식사가 건강에 미치는 영향에 대한 인식률 변화는 큰 영향이 있다고 답한 그룹이 실험군은 60.1%에서 64.8% (p<0.001)로, 대조군은 64.8%에서 57.2% (p<0.001)로 각각 변화하였다. 일찍 자기가 건강에 미치는 영향에 대한 인식률은 큰 영향이 있다고 답한 그룹이 실험군은 52.5%에서 70.7%(p<0.001), 대조군은 55.3%에서 60.2%로(p<0.001), 일찍 자기 실천에 대한 의지 변화는 11시 이전에 잘 계획이라는 그룹이 실험군은 31.9%에서 43.9%(p<0.001), 대조군은 35.5%에서 36.8%로 나타났다(p<0.001). 영양 표시에 관한 문항에서는 식품구매시 영양표시를 보고 구매한 경험이 없다는 군이 실험군에서는 58.2%에서 40.4%로 감소하였고(p<0.001), 대조군은 64%에서 53.6% (P<0.001)로 감소하였다. 영양소에 관한 지식 평가에서 짜지 않은 간식을 선택할 때 유의할 성분을 나트륨이라고 답한 그룹은 실험군은 31.7%에서 56.3%로, 대조군은 15.9%에서 23.0%로 나타나 그룹간 큰 차이를 보였다. 아침식사로 좋아하는 음식은 김치, 김치찌개, 밥, 피자, 고기, 빵, 된장찌개, 김, 햄, 계란후라이 순이었으며 싫어하는 아침음식은 피망, 고추, 양파, 김치, 시금치, 마늘, 콩, 파, 피자, 나물순으로 나타났다. 아침식사로 혼자서도 준비할 수 있는 음식은 밥, 라면, 계란후라이, 김치, 반찬, 볶음밥, 계란, 국, 햄, 씨리얼 순으로 나타났다. 부모의 인식률 변화는 가정내에 컴퓨터 설치장소로 적합하다고 생각되는 장소로 실험군의 경우 학생 방은 28.0%에서 21.6%로 6.4%감소하였고, 마루나 거실은 61.3%에서 66.0%로 5%증가하였다(p<0.001). 반면 대조군의 경우 학생 방은 28.8%에서 24.9%로 3.9% 감소, 마루나 거실은 63.4%에서 65.9%로 2.5%증가하여 실험군과 큰 차이를 보였다(p<0.001) 자녀의 늦은 취침시간과 아침식사에 관한 인식률 변화는 아침식사에 영향이 있다는 군은 실험군의 경우 78.1%에서 82.7%로 4.2% 증가하였고(p<0.05), 대조군의 경우 82.2%에서 80.5%로 감소하여 나타났다.(P<0.001) 연구결과 실험군의 경우 일주일 동안 아침을 전혀 먹지 않는 학생이 감소하고 매일 아침을 먹는 학생이 유의적으로 증가하여 아동의 아침식사 행동변화와 인식률 변화에 도움이 된 것으로 나타났다.

• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.141-156
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• 1990

The experiments were conducted to investigate the possibility of improving the effectiveness of the existing method to estimate the edible meat weight in the live broiler chicken. A total of 360 birds, five male and female chicks from each line were sacrificed at Trial 1 (body weight 900-1, 000g), Trial 2 (body weight 1.200-1, 400g), Trial 3(body weight 1, 600-1, 700), and Trial 4(body weight 2, 000g) in order to measure the body weight, edible meat weight of breast, thigh and drumsticks, and various components of body weight. Each line was reared at the Poultry Breeding Farm, Seoul National University from the second of july, 1987 to the thirteenth of September, 1987. The results obtained from this study were summarized as follows ： 1. The average body weights of each line( H. T, M, A) were $2150.5\pm$34.9, $2133.0\pm$26.2, $1960.0\pm$23.1, and $2319.3\pm$27.9, respectively. at 7 weeks of age. The feed to body weight eain ratio for each line chicks was 2.55, 2.13, 2.08, and 2.03, respectively, for 0 to 7 weeks of age. The viability of each line was 99.7. 99.7, 100.0, and 100.0%, respectively, for 0 to 7 weeks of age.01 was noticed that A Line chicks grow significantly heavier than did T, H, M line chic ks from 0 to 7 weeks of age. The regression coefficients of growth curves from each line chicks were bA＝1.015, bH＝0.265, bM＝0.950 and bT＝0.242, respectively. 2. Among the body weight components, the feather. abdominal fat, breast, and thigh and drumsticks increased in their weight percentage as the birds grew older, while neck. head, giblets and inedible viscera decreased. No difference wat apparent in shank, wings and hack. 3. The weight percentages of breast in edible part for each line thicks were 19.2, 19.0, 19.9 and 19.0% at Trial 4, respectively. The weight percentages of thigh and drumsticks in edible part for each line chicks were 23.1, 23.3, 22.8, and 23.0% at Trial 4. respective1y. 4. The values for the percentage meat yield from breast were 77.2. 78.9 73.5 and 74.8% at Trial 4 in H, T, M and A Line chicks. respectively. For thigh and drumstick, the values of 80.3, 78.4. 79.7 and 80.2% were obtained. These data indicate that the percentage meat yield increase as the birds grow older. 5. The correlation coefficients between body weight and blood. head, shanks. breast. thigh-drumstick were high. The degree if correlation between abdominal fat(%) and percentage of edible meat were extremely low at all times, but those between abdominal fat (%) and inedible viscera were significantly high.