• 한국작물학회지
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• 제49권5호
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• pp.373-380
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• 2004

The production of sweet (su) and super sweet corns (sh2) has been economically feasible in Korea in recent years. Major factors limiting super sweet corn production are low germination and low seedling vigor. Since seed quality is closely related to seed maturity, the optimum harvest time for the seed production of sweet and super sweet corns was studied and the quality of seeds with varying maturities was investigated in 2001 and 2002 cropping seasons. The parents of the sweet corn seeds were Hybrid Early Sunglow and 'Golden Cross Bantam 70' and those of super sweet corn were Xtrasweet 82 and 'For­tune'. Seeds were harvested at 21, 28, 35, 42, 49, and 56 days after silking (DAS). As the seeds developed, seed weight of sweet corn increased and the seed moisture content decreased faster than that of super sweet corn. Germination rates of sweet corn seeds harvested 21 and 28 DAS at $25^{\circ}C$ and emergence rates in the cold soil test were significantly lower than those of seeds harvested after 42 DAS in both years. Although the germination rates of super sweet corn seeds with varying maturities showed similar patterns as sweet corn seeds at $25^{\circ}C$, the emergence rate of super sweet corn seeds in cold soil test continuously increased with seed maturity. This suggests that seed quality of super sweet corn should be tested in a cold soil test to estimate field emergence. As the seeds developed, leakage of total sugars and electrolytes from the both sweet and super sweet corn seeds decreased up to 42 or 49 DAS. The $\alpha-amylase$ activities of both sweet and super sweet corn seeds increased with seed maturity from 21 to 35 or 49 DAS depending on genotype and year. The optimum harvest time for the seed production of sweet corn was 42 DAS and 49 DAS for super sweet corn considering emergence rate and plumule dry weight in the cold soil test, leakage of sugars and electrolytes from the seeds, and $\alpha-amylase$ activity.

• 한국작물학회지
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• 제32권1호
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• pp.16-23
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• 1987

다수다얼성 옥수수의 동위효소 특성을 구명하고 자얼성성 품종을 비교하여 생육단계에 따라 여러 조직을 6％ polyaclamide gel을 사용 peroxidase와 esterase 동위효소 패턴을 관찰하였던 결과는 다음과 같다. 1. 성숙한 옥수수의 엽, 간, 업소. 근 및 미숙종자의 조직에서 독특한 peroxidase의 동위효소의 존재가 확인되었다. 2. 암조건에서 7일간 자란 다수다얼성 계통의 중심주와 초엽조직은 peroxidase 도위효소의 차이를 나타내는데 효과적이었다. 3. Esterase의 동위효소에 대한 활성은 양친의 경위가 그들의 교잡종보다. 밴드수나 활성이 높았다. 4. Esterase에 대한 밴드는 암조건인 7 일 유묘상태의 중심주, 초엽, 미숙종자에서 뚜렸한 차이가 있었다. 5. 효과적인 동위효소 관찰을 위해서는 성묘보다는 유묘조직이 유리하게 보였다. 6. 흑조위축병에 감염된 옥수수 잎은 PX나 EST 동위효소에서 모두 뚜렷한 차이를 보였다.

• 한국작물학회지
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• 제33권4호
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• pp.386-391
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• 1988

보리의 교배육종에서 교배조합의 양부를 초기세대에 검정할 수 있는가를 Sakai의 이론에 따라 구명하기 위하여 보리의 수량형질인 추수, 입수, 수중, 개체별 입중에 대해서 5개 교배조합을 가지고 조사를 실시한 결과를 요약하면 다음과 같다. 1. 입수의 경우 3개 조합에서 그리고 수중의 경우는 1개 조합에서 상가적유전분산이 부의 방향으로 계산되었고 교배조합의 우량도를 계산할 수 없었으나 나머지 조합과 형질에서는 무난히 계산이 가능하였다. 2. 수수에 대한, 교배조합의 우량도 Y는 SB 76588$\times$SB72648 조합이 제1위였다. 또 이 조합은 F$_4$ 집단의 상위 5 % 및 10%내 식물의 평균순위에서도 2위를 하여 수수에 대해서는 이 조합이 5개 조합중 가장 좋은 조합으로 인정되었다. 3. 수당입수에 있어서는 3개 조합에서 Y값의 추정이 불가능하였으나 나머지 2조합을 가지고 보았을 때 F$_4$ 집단의 순위가 높고 Y값도 높은 밀양 006$\times$수원20003 조합이 우량조합인 것으로 보이었다. 4. 수종에서는 Y계산이 불가했던 1개 조합을 제외한 나머지 조합에서 Y에 의한 순위와 F$_4$에의 한 순위와 대체로 일치하였고 밀양006$\times$수원 20003 조합이 우수조합으로 나타났다. 5. 개체별 입중에서도 Y값에 의한 순위와 F$_4$에 의한 순위가 대체로 일치하였고 SB76588$\times$SB72648 조합이 가장 우수한 조합인 것으로 나타났다.

• 한국동물학회지
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• 제31권1호
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• pp.29-34
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• 1988

초기 발생과정에 있어서 핵과 세포질이 상호작용을 조사하기 위하여 양서류 한 종의 핵을 이조의 무핵 수정란에 치환하였다. Rana속에 속하는 R.dybowskii,R.nigromaculata,R.pipiens등의 이종간 잡종의 개체의 경우 낭배초기를 전후하여 발생이 중지되며,Rana,Xenopus그리고 Axolotl의 속간 핵치환에서는 후기포배기에 발생이 중지되는 양상을 보인다. 이때 각 핵-세포질 조합의 발생수행능력을 비교하면 계통발생상의 유연관계가 먼 종일수록 초기에 발생이 중지되는 결과를 나타냈다. 일반적으로양서류 종간 핵치환 결과는 후기 포배까지는 정상발생양상을 보이고 있다. 이와같은 잡종개체가 초기에 발생수행능력의 제한을 받는 요인은 두가지로 생각할 수 있는데, 치환된 핵에 비가역적 변화가 일어났을 가능성과 핵과 세포질간의 기능적 비양립성이 그것으로 현재로서는 후작 좀 더 가능성 있는 요인으로 사료된다.

• 농업과학연구
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• 제40권2호
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• pp.123-129
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• 2013

An experiment was conducted to evaluate the effects of nitrogen supplementation through urea-molasses multinutrient block (UMMB) on the performance of dairy cows fed good quality forage based diets with rice straw as a night feeding. A total of 10 multiparous crossbred dairy cows in their early lactation were grouped into two categories based on their breed, parity, body weight, milk yield, milk fat and protein contents and daily fed a chopped CO-3 grass (Pennisetum purpureum ${\times}$ Pennisetum americanum; hybrid Napier) ad-libitum, 1 kg of dairy cow concentrate feed during the day time and 5 kg of rice straw (dry matter basis) at night as the basal diet (control) for 5 wk. In addition to the basal diet, the treatment group received 300 g of crushed UMMB daily throughout the experimental period. Cows were milked twice daily and the milk yields were recorded. Milk and feed samples were collected weekly for chemical analysis. Supplementation of UMMB had no significant effects (p>0.05) on straw intake, daily milk yield, contents and yields of milk constituents such as milk fat, protein, lactose and solids-non-fat. In addition, milk urea nitrogen content were not affected (p>0.05) by UMMB supplementation. However, numerical increments in all the parameters measured were observed during the study in cows fed diets supplemented with UMMB. It can be concluded that nitrogen supplied through UMMB had no effects on production performances of dairy cows in this study.

• Restorative Dentistry and Endodontics
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• 제26권4호
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• pp.316-325
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• 2001

The purpose of this study was to evaluate the effect of adhesive curing timing on the direction of polymerization shrinkage of light-curing composite resin. In this study, the curing times of adhesive and composite resin were measured by differential scanning calorimeter(DSC). 28 extracted human molars were embedded in clear resin and box-type cavities were prepared. Based on DSC data, the experimental teeth were divided into 4 groups. Group 1: no bond; Group 2: late curing; Group 3: Intermediate curing; Group 4: Early curing. After treating with adhesive, the buccal cavities were filled with Z-100 hybrid composite resin and the lingual ones were filled with AEliteflo flowable composite resin. The depressions at the surface were measured by surface profilometer, then the specimens were embedded in clear resin and sectioned. Impressions were obtained and used to get epoxy resin replicas. The epoxy replicas were gold-coated and observed under SEM. Average Maximum Gap(AMG), Gap Proportion(GP), Average Marginal Index(AMI) were used to compare the shrinkage gap of each group. The results were statistically analyzed using the Kruskal-Wallis One Way ANOVA, Student-Newman-Keuls method. The results of this study were as follows. 1. Average Maximum Gap, Gap Proportion, Average Marginal Index and depression at the surface or Z-100 hybride composite resin were smaller than those of AEliteflo flowable composite resin(P<0.05). 2. When the bonding between composite resin and tooth structure was strong, the shrinkage gap was small, and depression at the surface was deep(P<0.05). 3. In the well-bonded group, light-curing composite resin shrank toward bonded cavity wall, not toward light source. The result suggested that the direction of polymerization shrinkage was affected by the quality of bonding in the dentin-resin interface. The strong was the bonding between composite resin and tooth structure, the smaller was the gap and the deeper was the depression at the surface. Then the flow to compensate the polymerization shrinkage proceeded from surface to bonded cavity wall.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 추계학술발표대회
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• pp.39-45
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• 2000

It hab been proposed that CHS3-mediated chitin synthesis during the vegitative cell cycle is regulated by CHS4. To investigate direct protein-protein interaction between their coding products, we used yeast two hybrid system and found that a domain of Chs3p was responsible for interaction with Chs4p. This domain, termed MIRC3-4 (maximum interacting region of chs3p with chs4p), spans from 647 to 700 residues. It is well conserved among CHS3 homologs of various fungi such as Candida albicans, Emericella nidulans, Neurospora crassa, Magnaporthe grisea, Ustilago maydis, Glomus versiforme, Exophiala dermatitidis, Rhizopus microsporus. A series of mutaion in the MIRC3-4 resulted in no appearance of chitin ring at the early G 1 phase but did not affect chitin synthesis in the cell wall after cytokinesis. Absence of chitin ring could be caused either by delocalization of Chs3p to the septum or by improper interaction with Chs4p. To discriminate those two, not mutually exclusive, alternatives, mutants cells were immunostained with Chs3p-specific antibody. Some exhibited localization of chs3p to the septum, while others failed. These results indicate that simultaneous localization and activation Chs3p by Chs4p is required for chitin ring synthesis.

• Investigative Magnetic Resonance Imaging
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• 제25권3호
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• pp.141-155
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• 2021

Purpose: To develop a 3D magnetic resonance fingerprinting (MRF) method for application in high resolution knee cartilage PD, T₁, T₂ mapping. Materials and Methods: A novel 3D acquisition trajectory with golden-angle rotating radial in k_xy direction and interleaved echo planar imaging (EPI) acquisition in the k_z direction was implemented in the MRF framework. A centric order was applied to the interleaved EPI acquisition to reduce Nyquist ghosting artifact due to field inhomogeneity. For the reconstruction, singular value decomposition (SVD) compression method was used to accelerate reconstruction time and conjugate gradient sensitivity-encoding (CG-SENSE) was performed to overcome low SNR of the high resolution data. Phantom experiments were performed to verify the proposed method. In vivo experiments were performed on 6 healthy volunteers and 2 early osteoarthritis (OA) patients. Results: In the phantom experiments, the T₁ and T₂ values of the proposed method were in good agreement with the spin-echo references. The results from the in vivo scans showed high quality proton density (PD), T₁, T₂ map with EPI echo train length (N_ETL = 4), acceleration factor in through plane (R_z = 5), and number of radial spokes (N_spk = 4). In patients, high T₂ values (50-60 ms) were seen in all transverse, sagittal, and coronal views and the damaged cartilage regions were in agreement with the hyper-intensity regions shown on conventional turbo spin-echo (TSE) images. Conclusion: The proposed 3D MRF method can acquire high resolution (0.5 mm³) quantitative maps in practical scan time (~ 7 min and 10 sec) with full coverage of the knee (FOV: 160 × 160 × 120 mm³).

• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.224-232
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• 2019

Objective: Apart from various climatic differences, corn harvest stage and varieties are two major factors that can influence the yield and quality of corn silage in the tropics. A study was conducted to determine the optimum harvest stage of four corn varieties for silage production in Malaysia. Methods: Corn was harvested at four growth stages; silking, milk, dough, and dent stages from four varieties; Sweet Corn hybrid 926, Suwan, breeding test line (BTL) 1 and BTL 2. Using a split plot design, the treatments were then analysed based on the plant growth performance, yield, nutritive and feeding values followed by a financial feasibility study for potential commercialization. Results: Significant differences and interactions were detected across the parameters suggesting varying responses among the varieties towards the harvest stages. Sweet Corn was best harvested early in the dough stage due to high dry matter (DM) yield, digestible nutrient, and energy content with low fibre portion. Suwan was recommended to be harvested at the dent stage when it gave the highest DM yield with optimum digestible nutrient and energy content with low acid detergent fibre. BTL 1 and BTL 2 varieties can either be harvested at dough or dent stages as the crude protein, crude fibre, DM yield, DM content, digestible nutrient and energy were not significantly different at either stage. Further financial analysis showed that only Sweet Corn production was not financially feasible while Suwan had the best financial appraisal values among the grain varieties. Conclusion: In conclusion, only the grain varieties tested had the potential for silage making according to their optimum harvest stage but Suwan is highly recommended for commercialization as it was the most profitable.

• 문화기술의 융합
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• 제5권1호
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• pp.297-303
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• 2019

본 연구는 컴퓨팅 사고력에 기초한 유아를 위한 언플러그드 코딩의 특성과 개념, 유형, 전략을 알아보는 데 목적이 있다. 유아를 위한 언플러그드 코딩의 핵심은 컴퓨팅 사고력이다. 유아를 위한 컴퓨팅 사고력에 기초한 언플러그드 코딩은 프로그램을 사용하지 않고 알고리즘 판, s-블럭, 코딩 로봇, 스마트 기기 등을 긍정적으로 활용하여 논리적 사고를 기반으로 놀이를 통해 일상 생활 속에서 만날 수 있는 문제를 해결하고 새로운 놀이 방법을 찾는 것이다. 유아를 위한 언플러그드 코딩의 유형은 스마트 기기에 직접 입력하기, 전용 앱을 이용한 코딩 로봇 활용하기, 알고리즘을 활용한 코딩절차 연습하기, 혼합형 방법 사용하기가 있다. 전략으로 알고리즘 이해하기, 순서도 그리기, 작은 부분으로 나누기, 패턴 찾기, 벌레 잡기, 결과 예측하기가 있다.