• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.826-835
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• 1999

Background : The $\beta_2$ adrenergic receptor ($\beta_2$ AR) polymorphisms occurring at amino acid position 16 (Arg to Gly), 27 (Gln to Glu), 34 (Val to Met), and 164 (Thr to Ile) are known to be functionally relevant and also disease-modifying in subjects with asthma. However the contribution of these polymorphisms to the development of the asthmatic phenotype or other markers for allergic disease remains to be established. Methods : 109 patients with bronchial asthma and 42 healthy person were included. Serum total IgE, allergen specific IgE, and skin prick test were performed to all of the subjects. $\beta_2$ AR polymorphisms were checked by mutated allele specific amplification (MASA) method. Results : The results were as follows. The frequencies of $\beta_2$ AR polymorphisms in asthmatic patients and healthy person were not statistically different(p>0.05). There was no association between $\beta_2$ AR polymorphisms of amino acid position 16, 27, 34 and the existence of atopy among asthmatic patients(p>0.05). Between asthmatic patients with or without elevated IgE level and $\beta_2$ AR polymorphisms of amino acid position 16, 27, 34, there was no statistically significant association(p>0.05). Conclusion : There was no difference in frequency of the $\beta_2$ AR polymorphism between asthmatic patients and healthy person. In the bronchial asthma, association of $\beta_2$ AR polymorphism and atopy/serum total IgE was not found.

• Journal of Life Science
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• v.21 no.4
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• pp.494-501
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• 2011

To understand the relationship between coat color inheritance patterns and genotypes of Extension (E) and Agouti (A) loci in cattle, the genotypes for melanocortin-1 receptor (MC1R) and agouti signaling protein (ASIP) were analyzed in Hanwoo, Jeju black cattle (JBC), and their crossbred progeny. Three MC1R alleles ($E^D$, $E^+$, and e) were found in the black-colored JBC population. JBC had no recessive homozygotes (e/e), but this genotype was predominant in the Hanwoo breed. However, MC1R $E^+$/e Hanwoo did not produce a black coat color as they appeared either as brown or solid red. For ASIP, three genotypes (A/A, A/$A^{Br}$, and $A^{Br}/A^{Br}$) were determined by insertion/deletion of an L1-BT element in Hanwoo. The ASIP $A^{Br}$ allele was rarely observed, and no ASIP $A^{Br}/A^{Br}$ homozygotes were detected in the JBC population. Cattle carrying ASIP $A^{Br}$ did not show any agouti-like brindle pigmentation patterns in either breed or their progeny. The coat colors of the crossbred progeny were discriminated by two colors, yellowish-brown versus dark-brown or black, and their coat colors were directly related to the genotypes of the Extension locus, yellowish-brown (e/e) and dark-brown or black ($E^+$/e), but not to the Agouti locus. ASIP genotypes probably did not affect coat color development in the Hanwoo or crossbred progeny. Our results suggest that the ASIP genotypes do not play key roles in coat color variation, but the MC1R genotypes do direct the phenotypes of Hanwoo, JBC, and their progeny.

• Journal of Genetic Medicine
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• v.8 no.2
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• pp.113-118
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• 2011

Purpose: Placental corticotropin-releasing hormone receptor type 1 (CRHR1) expression is reduced in pregnancies with abnormal placental function such as preeclampsia (PE), and the levels and/or function of CRHR1 are genetically influenced. The aim of this study was to investigate the association between the c.33+8199C>T polymorphism in the CRHR1 gene and PE in a Korean population. Materials and Methods: Using a case-control design, the association between the CRHR1 polymorphism and the risk of PE was investigated in 203 individuals with PE and 211 normotensive controls. Genotypes were determined using a SNapShot kit and an ABI Prism 3100 Genetic analyzer. Results: Genotypes and allele frequencies for the CRHR1 polymorphism did not differ between PE and normotensive pregnancies. The variant T allele was more frequent than the ancestral C allele in both of the groups and was more frequent in the controls than in the cases. In risk analysis for PE, there was not an increased risk of preeclampsia in subjects who were concomitant homozygous rare allele genotypes (CC) (OR, 0.3; P=0.15) or heterozygous rare allele genotypes (TC) (OR, 0.8; P=0.29). There were no differences in the complications of PE such as severity or preterm delivery in patients with the CRHR1 polymorphism. Conclusion: Our findings indicate that the CRHR1 polymorphism was not associated with PE in the present Korean study group.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.345-359
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• 1989

This study was conducted to estimate genetic variation of Pinus densiflora in Kyungpook province which shows morphological variation between northern and southern types. Six isozymes sueh as IDH, ME, PGI, ADH, GOT and LAP was analyzed using megagametophyte tissue of seeds by electrophoresis and 16 populations of Pinus densiflora and 5 of Pinus thunbergii were tested. The results obtained were as follows ; 1. In P. densiflora, 13 Loci were found in 6 isozymes and 8 loci of them were polymorphic, having 24 alleles, while in Pinus thunbergii, there were 18 alleles detected from 6 loci among the same number of loci as in Pinus densiflora. 2. The genotypic frequency in Pinus densiflora vary slightly among populations for some isozymes, but most of them satisfied the law of Hardy-Weinherg equilibrium, while some populations such as Youngil for ADH and LAY, Youngyang for ADH and Bonghwa for LAY did not follow the law and showed high fixation index values and homozygosities higher than expected. 3. The variation among populations based on the genetic distance was small except populations of Youngju, Baegam, Gyungju and Sangju, however they could be clustered by three groups : northern Kyungpook group including Mt. Taebak, inland Kyungpook group represented by Sungju, Eusung and Kumleung population and coastal Kyungpook group represented by Baegam and Gyungju population. 4. No significant difference was found in 6 isozymes between northern and southern types of Pinus densiflora which was morphologically different. 5. The frequency of heterozygous loci per tree was higher in Pinus densiflora especially for ME-A and A DH-B, while that of homozygous loci was higher in Pinus thunbergii except for ADH-B, LAY-B and PGI-B locus.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.463-471
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• 2018

Perilla is an oilseed crop cultivated in Korea since ancient times. Due to the high ${\alpha}-linolenic$ acid content in perilla, perilla seed oil can easily become rancid. ${\alpha}-Linolenic$ acid is synthesized by two enzymes, endoplasmic reticulum-localized ${\Delta}15$ desaturase (FAD3) and chloroplast-localized ${\Delta}15$ desaturase (FAD7) in vivo. In order to lower the ${\alpha}-linolenic$ acid content of the seed oil without disturbing plant growth, we tried to suppress the expression of only the FAD3 gene using RNA interference, whilst maintaining the expression of the FAD7 gene. Seventeen transgenic plants with herbicide ($Basta^{TM}$) resistance were obtained by Agrobacterium-mediated transformation using hypocotyls of perilla plants. The transgenic plants were firstly confirmed by treatment with 0.3% (v/v) $Basta^{TM}$ herbicide, and the expression of FAD3 was measured by Northern blot analysis. The ${\alpha}-linolenic$ acid content was 10-20%, 30-40%, and 60% in two, seven, and three of the twelve $T_1$ transgenic perilla plants which had enough seeds to be analyzed for fatty acid composition, respectively. Analysis of the fatty acid composition of $T_2$ progeny seeds from $T_1$ plants with the lowest ${\alpha}-linolenic$ acid content showed that the homozygous lines had 6-10% ${\alpha}-linolenic$ acid content and the heterozygous lines had 20-26% ${\alpha}-linolenic$ acid content. It is expected that the reduction in ${\alpha}-linolenic$ acid content in perilla seed oil will prevent rancidity and can be utilized for the production of high-value functional ingredients such as high ${\gamma}-linolenic$ acid.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.577-584
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• 2011

To estimate level of genetic variation and genetic differentiation among populations of 3 populations in Abies koreana and 5 populations in Abies nephrolepis, 5 nSSR markers were analyzed. Except 1 locus where too many alleles were observed excessively, population genetic parameters were recalculated with 4 loci. Mean expected heterozygosities ($H_e$) were 0.292 in A. koreana and 0.220 in A. nephrolepis, respectively. In both species, positive fixation coefficient was estimated (F=0.065 for A. koreana and F=0.095 for A. nephrolepis), which suggests that there is an excess of homozygotes relative to Hardy-Weinberg expectations within populations. Relatively high degree of population differentiation was observed in A. koreana ($F_{ST}=0.063$). compared to that of A. nephrolepis ($F_{ST}=0.039$). From 3-level Hierarchical estimation of F-staticstics, only 4.9% of the genetic variation was allocated between species ($F_{PT}$), which suggested that most of genetic variation was shared between two species. On the basis of results from analysis of genetic relationships among populations, 2 populations of A. koreana (Mt. Halla and Mt. Deogyu) were genetically distinct from the populations of A. nephrolepis but a population of Mt. Jiri was allocated within a group of populations of A. nephrolepis. Populations of both species seemed to have undergone genetic drift due to gradual decrease in population size induced by global warming after the last glacier, which resulted in increase of homozygotes by inbreeding. It could be also postulated that these species might be diverged recently and It is likely that the two species have not fully speciated yet.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.569-576
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• 2007

receptor(MC4R) gene and carcass traits was examined in randomly selected commercial pigs. A porcine MC4R gene was genotyped for Asp298Asn(nt. 892G>A) by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). A total of three genotypes, A/A, A/G, and G/G, were found with 28.8, 22.8, and 48.4% frequencies, respectively. In the whole population, pigs containing 892A/- showed significantly higher marbling score than those of homozygotes G/G(P<0.05). Two homozygotes, A/A and G/G showed lower in meat color score but higher in water holding capacity than those of heterozygotes A/G(P<0.01). However, the carcass weight of the barrows containing wild type -/G was significantly higher(i.e. more than 2.5kg) than those of homozygotes A/A(P<0.05). The effects of each genotype on carcass traits in the gilts were similar to those of the whole population, but not in barrows, suggesting an unknown sex-related effect on carcass traits. This study suggested that the genotype MC4R A/- could improve the meat quality in the commercial pig production. However, since the genetic polymorphism of MC4R gene differentially affected the carcass traits in sex-related manner, therefore, both parameters, the sex and genotype, should be considered for marker-assisted selection in commercial pig production.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.33-41
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• 2020

The landing gear of an aircraft is a device that absorbs and dissipates shock energy transmitted from the ground to the fuselage. Among the landing gears, the semi-active MR damper landing gear is supposed to show high-shock absorption efficiency under various landing conditions and secure the stability when out of control. In the case of the MR damper landing gear using an annular channel rather than orifice, Amesim, a commercial multi-physics program, is considered as more useful than the conventional two-degree-of-freedom model because the damping force generated by the pressure drop through the flow annular path can cause cavitation in the low-pressure chamber of the MR damper with a specific internal structure. In this paper, the main dynamic characteristics of the MR damper landing gear with an annular type flow path structure has been analyzed under the condition of cavitation. Based on the analysis results using Amesim, a design guideline for the MR damper flow path that prevents cavitation has been proposed based on the modification of the arrangement of internal components of the damper. The guideline was verified through a drop simulation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.6-6
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• 2017

농용트랙터의 전방차축 현가장치는 노면으로부터 발생하는 진동의 영향을 줄일 수 있기 때문에 트랙터의 대형화, 고속화의 추세에 맞춰서 승차감과 조향감을 향상시키는 데 중요한 역할을 한다. 전방차축의 현가장치는 트랙터의 차체 무게에 의한 부하가 크고, 또한 유압 펌프를 비롯한 유압시스템이 존재하기 때문에 유압식 회로로 구성하는 것이 바람직하다. 하지만, 현가장치의 유압회로를 개발하는데 있어서 실제 시스템을 구성하여 실제 실험을 통한 개발에는 비용과 시간이 많이 필요하다. 본 연구에서는 유압식 전방차축 현가장치에 필요한 유압회로부 개발을 위하여 시뮬레이션 기법과 요인시험 장치를 이용 적정 유압회로를 설계하고자 하였다. 이를 위하여 어큐뮬레이터, 가변 오리피스, 릴리프밸브, 체크밸브 등으로 구성된 유압 현가요인 시험 장치를 설계 제작하였으며, 현가 부품인 실린더 행정, 속도, 전달되는 힘을 측정하고, 유압 해석 프로그램인 SimulationX를 이용 구성된 유압회로 부품에 측정값을 입력하여 실제 조건과 유사한 동특성을 나타내는 전방차축 현가요인 시뮬레이션 모델을 개발하였다. 개발된 시뮬레이션 모델을 이용하여 실제 시험조건과 같은 가진 조건을 부여하여 개발 현가장치의 특성 값 변동에 따른 현가 성능을 구명하였다. 이를 위해 시뮬레이션 상에서 120 마력 트랙터 무게의 50% 수준에 해당하는 2,000 kg의 부하가 존재하는 상태에서 현가장치의 유/무에 따른, 감쇠 계수의 변화에 따른 스프링상 질량의 RMS 가속도를 비교하였다. 입력 가진으로는 1 Hz, 4 Hz, 8 Hz의 진동수에 각각 10 mm, 6.4 mm, 3.2 mm의 진폭을 인가하였다. 시뮬레이션 결과, 1 Hz에서는 현가장치가 있는 경우 최대 55.9% 개선되었고, 4 Hz에서는 최대 3.9 % 개선되었고, 8 Hz에서는 최대 61.4%까지 개선되었다. 이는 4 Hz의 경우에는 2,000 kg의 부하에 해당하는 고유 진동수 대역에 해당하기 때문에 그 감쇠 효과가 없는 것으로 나타났다. 하지만, 다른 주파수 대역에서는 현가장치가 효과적으로 작동하는 것을 나타내었다. 설계한 전방차축 현가 유압회로부를 시뮬레이션을 통하여 분석한 결과, RMS 가속도의 개선이 명확하게 이루어지는 것을 확인하였으며 입력 주파수 변화에 따라 감쇠특성도 나타나는 것을 확인하였다. 추후 연구에는 설계한 유압회로부와 관련 부품을 설계 제작하여 실제 트랙터에 장착 그 성능을 검증할 예정이며, 노면조건에 따라 감쇠성능을 유지하기 위한 반능동형 또는 적응형 현가장치 제어 기술을 적용하여 개선된 현가성능을 확보하기 위한 연구를 수행할 예정이다.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.95-104
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• 2008

The purpose of this study was to investigate kinematic coordination and control of lower segments in skill process. For the investigation, we examined the difference of resultant linear velocity of segments and angle vs angle graph. Novice subjects were 9 male middle school students who has never been experienced a taekwondo and expert subjects were 7 university taekwondo players. We analyzed kinematic variables of Dollyochagi motion through videographical analysis and the conclusion were as follows. 1. Examining the graph of novice subjects' maximal resultant linear velocity of the thigh, shank, and foot segment, as it gets closer to the end of the training, the maximal resultant linear velocity in each segment increased. Statistical analysis showed the following results; thigh segment caused the increase of speed, using the trunk segment's momentum in the latter term of learning, while the shank segment utilized the momentum of the adjacent proximal segment at the beginning of learning, and the foot segment in the middle of learning. 2. Until the point where the knee joint angle is minimum, as the novice group learn the skill, the flexion of knee and hip joints has changed into the form of coordination pattern in phase. On the other hand, the expert group showed continual coordination pattern in phase that the movement sequences were smooth. From the knee joint maximal flexion to impact timing, all novice and expert groups showed coordination pattern out of phase. 3. From the knee joint maximal flexion to impact timing, the ankle joint was fixed and the knee joint was extended to all the novice stages and expert subjects.