• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.281-313
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• 1976

To obtain fundamental informations on cotton breeding efficiences for Korea, individual genetic relationships and interrelationships between the agronomic characteristics of Upland cotton were investigated. These experiments were couducted at the Mokpo Branch Station $(34^{\circ}48'N, $ $126^{\circ}23'E$ and altitude of 10m above sea level) from 1969 through 1972. Heterosis, combining ability, dominance and recessive gene action, genetic variance, and phenotypic and genotypic correlation were investigated by $F_1'S$ from an 11-parent partial diallel cross and the segregating $F_2$ and $F_3$ populations of the cross Paymaster times Heujueusseo Trice. The following points resulted from this study, 1. Heteroses for number of bolls per plant and lint yield were significant at 27, 84% and 37.26%, respectively. No other character had significant heteroses. 2. The GCA estimates for all studied characteristics were higher than the SCA estimates. Varieties with high GCA effects were Suwon 1 for earliness, Paymaster and Arijona for high lint percent, and Arijona for long fiber, etc, 3. SCA estimates for lint yield varied widely in crosses with Mokpo 4, Mokpo 6 and Heujueusseo Trice. Those crosses with the highest SCA effects were combinations with large characteristics differences, Example of these crosses are Mokpo 4 times Acala 1517W, Mokpo 4 times D. P. L. and Heujueusseo Trice aud Paymaster. 4. Early-maturing varieties were completely dominant to late-maturing varieties in some combinations while other crosses gave intermediate phenotypes. These results suggest additive genetic action by multi-genes. Heujueusseo Trice, Mokpo 6, and Suwon 1 showed highest degree of dominance for earliness. 5. There were no significant trends for inheritance of weight of boll and 100 seeds weight. 6. Long staple was partially to completely dominant to short staple. Though there were single gene ratios the rate of dominance decreased in the $F_2$ and $F_3$ populations in the cross between the long staple variety Paymaster and the short staple variety Heujueusseo Trice. Diallel cross $F_1$ hybrids showed complicated allelic gene action for staple length. Various dominance degree were shown by varieties. 7. Number of bolls per plant indicated strong over-dominance and small non-allelic additive gene action. 8. Lint Yield was characterized by over-dominance and by multiple non-allelic-gene action. High-yielding varieties were dominant to low-yielding ones. However, the low-yielding variety Heujueusseo Trice showed over-dominance, indicating different reactions according to the varieties and combinations. 9. Broad sense heritability for days to flowering was 34-39% while narrow sense heritability was 11%. Large variations of individual plants caused by Korean climatic conditions cause this situation. Heritability estimates for weight of boll was 30% for broad sense and 22% for narrow sense. 10. Heritability estimates for staple length and lint percent were very high suggesting strong selection effects. 11. Narrow sense heritability estimates for number of bolls per plant was 30% in the diallel cross $F_1$ hybrids and 36% in the $F_2$ population of the special cross. Broad sense heritability was estimated at 67% suggesting that. 12. Heritability estimates for lint yield was low due to high over-dominance in the diallel cross $F_1$ hybrids. Heritability estimates for yield was low in the $F_1$ hybrids but high in the $F_2$ and $F_3$ populations. 13. Phenotypic and genotypic correlations between lint percent and days to flowering and between staple length and days to flowering were high in the $F_1, $ $F_2$ and $F_3$ populations. Late-maturing varieties and individuals had long staple and high lint percent in general. As the correlation between days to flowering and lint yield was extremely low, the two traits were considered independent of each other. Days to flowering and number of bolls per plant were negatively correlated in the $F_3$ population, indicating early-maturing individual plants with many bolls may be readily selected. 14. Phenotypic and genotypic correlations between lint percent and staple length were high in $F_1, $ $F_2$ and $F_3$ populations. Accordingly, long staple varieties were high in lint percent. It was recognized that lint yield and lint percent were positively correlated in the diallel cross $F_1$ hybrids, and lint percent and staple length were positively correlated in the $F_2$ population, indicating that lint percent and staple length affect lint yield. 15. Lint yield was significantly and positively phenotypically correlated with number of bolls per plant in $F_1, $ $F_2$ and $F_3$ populations. A high genotypic correlation was also noted indicating a close genetic relationship. The selection efficiencies for a high-yielding variety can be increased when individual plants with many bolls are selected in later generations. The selection efficiencies for good fiber quality can be enhanced when individuals with long staple and high lint percent are selected in early generations.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.223-230
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• 1994

Clonorchiasis is an important parasitic disease of humans in Korea. The present study intended to compare sonographic findings with histopathological changes in experimental clonorchiasis. Eighteen New Zealand white rabbits were infected with metacercariae of Cknorchis sinensis, and examined 4, 10, and 22 weeks post-infection (PI). Four infected rabbits were treated with praziquantel 10 weeks PI and were examined 12 weeks after treatment. Sonography revealed mild to severe dilatation of the intrahepatic ducts (IHDD) and slightly increased periductal echoes in 12 out of 14 rabbits at 4 weeks PI, and all of the animals after 10 and 22 weeks PI and 12 weeks after treatment. The histopathological lesions were duct dilatation, mucosal hyperplasia, and periductal fibrosis, which progressed from 4 weeks to 22 weeks PI and even in treated rabbits. The dilated intrahepatic ducts over 1 mm diameter were detected by sonography. The present results indicate that sonographic findings are well correlated with histopathological lesions in rabbit clonorchiasis except for early phase of light burden of infection. The sonography has a limitation in discriminating residual sequelae of the ducts after praziquantel treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.501-508
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• 1987

Gonadal development, the annual reproductive cycle and the first sexual maturity of hen clam, Mactra chinensis were studied histologically. Sexuality of the species was dioecious. The gonads were irregularly arranged from the subregion of mid-intestinal 91an4 in visceral cavity to the reticular connective tissue of the foot. The ripe eggs were about $50-60\;{\mu}m$ in diameter, and they were surrounded by gelatinous membrane. The spawning period was from May to September when the water temperature ranged $18.5-27.0^{\circ}C$, with the peak in June and July. The annual reproductive cycle of Mactra chinensis could be classified into five successive stages; multiplicative, growing, mature, spent, and degenerative and resting. The monthly changes of the fatness coefficient closely correlated with the annual reproductive cycle. Percentages of the first sexual maturity of female and male clams were over $50\%$ among those individuals ranging from 3.5 to 3.9cm, and $100\%$ in those over 5.0cm in shell length.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.124-124
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• 2022

대마(Cannabis sativa)는 카나비노이드(cannabinoids) 계열의 성분으로 인한 약리효능 뿐만 아니라 섬유, 식품 등의 분야에서도 식물소재로 활용도가 높은 것으로 알려져 있다. 최근 의료용 대마의 경우 규제완화가 예정됨에 따라 관련 산업분야에서도 안정적 원료 소재 생산에 대한 연구가 요구되고 있다. 대마는 실생번식이 가능한 종이나, 의료용 등 소재의 안정적 공급을 위해서는 균일한 cannabidiol(CBD) 성분의 확보가 가능한 영양증식 방법이 대안으로 사용될 수 있다. 따라서 본 연구에서는 영양증식 방법 중 조직배양 기술을 이용한 대마 품종별(Cherry Blossom, Queen Dream과 Hot Blonde) 증식법 구명을 위하여 식물생장조절제의 종류 및 농도에 따른 기내생육특성을 조사하였다. 세 품종 모두 1 mg l^-1 thidiazuron (TDZ) 단독처리 시 신초(> 2cm)가 가장 많이 유도되었다. 단 Queen Dream 품종은 0.5 mg l^-1 와 TDZ 0.2 mg l^-1 NAA 혼용처리구에서 많은 수의 신초가 유도되었으나 상대적으로 신초의 길이(< 2cm)는 짧은 것으로 확인할 수 있었다. 발생된 신초는 MS 기본배지에서 발근을 유도한 후 토양에 순화하여 정상적인 식물체로 발달되었다. 이와 같은 식물생장조절제 처리를 포함한 식물조직배양 방법은 유용 개체·품종의 증식 및 의료·산업용 원료 소재의 안정적 생산에 활용될 수 있다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.31-39
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• 2021

In this study, the fiber blending ratio and strain rate effect on the tensile properties synergy effect of hybrid fiber reinforced cement composite was evaluated. Hooked steel fiber(HSF) and smooth steel fiber(SSF) were used for reinforcing fiber. The fiber blending ratio of HSF+SSF were 1.5+0.5, 1.0+1.0 and 0.5+1.5vol.%. As a results, in the cement composite(HSF2.0) reinforced with HSF, as the strain rate increases, the tensile stress sharply decreased after the peak stress because of the decrease in the number of straightened pull-out fibers by increase of micro cracks in the matrix around HSF. When 0.5 vol.% of SSF was mixed, the micro cracks was effectively controlled at the static rate, but it was not effective in controlling micro cracks and improving the pull-out resistance of HSF at the high rate. On the other hand, the specimen(HSF1.0SSF1.0) in which 1.0vol.% HSF and 1.0vol.% SSF were mixed, each fibers controls against micro and macro cracks, and SSF improves the pull-out resistance of HSF effectively. Thus, the fiber blending effect of the strain capacity and energy absorption capacity was significantly increased at the high rate, and it showed the highest dynamic increase factor of the tensile strength, strain capacity and peak toughness. On the other hand, the incorporation of 1.5 vol.% SSF increases the number of fibers in the matrix and improves the pull-out resistance of HSF, resulting in the highest fiber blending effect of tensile strength and softening toughness. But as a low volume fraction of HSF which controlling macro crack, it was not effective for synergy of strain capacity and peak toughness.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.274-277
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• 2012

지구온난화의 폐해 중 하나인 해파리의 대량증식은 환경 생태계에 좋지 않은 영향을 미치고 있고, 또한 과도한 개체수는 원할한 처리가 곤란해 많은 문제점을 초래하고 있는 실정이다. 이러한 해파리의 생산적이고 효율적인 개선방안으로 단순 가공식품 뿐만 아니라 해파리의 추출을 통해 산업적으로 활용가능한 기능성 화장품원료로의 응용가능성도 고려해 볼 수 있을 것이다. 따라서 본 연구는 보름달물 해파리 유래 추출물의 기능성 화장품 원료로서의 안전성 및 유효성을 규명하였다. 인간피부섬유아세포에서의 세포독성, 주름 개선 효과와 관련된 procollagen 발현양의 증가 및 노화로 증가되는 SA-${\beta}$-Gal 효소의 활성을 염색을 통하여 확인하였고, 항노화 화장품 신소재로서의 사업화 가능성을 확인 할 수 있었다.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.585-592
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• 2004

Our previous studies demonstrated that relaxin in concert with estrogen promotes development of the mammary parenchyma during the last third of gestation in gilts, and the specific relaxin-binding sites were present in the mammary gland. This study was conducted to determine if relaxin-binding sites in the mammary gland were functional relaxin receptors. Three cycling cross-bred gilts were bilaterally ovariectomized on day 0 of the experiment. Beginning on day 15 and continuing through day 29 post-surgery, the gilt received an im. injection of estradiol benzoate at 12-hr intervals. Beginning on day 22 post-surgery, highly purified porcine relaxin was administered(lug/hr) into the left fourth mammary gland from the anterior end via miniature osmotic pump. Physiological saline was administered to the right fourth mammary gland. The gilt was sacrificed on day 29 post-surgery and histological characteristics of the mammary parenchyma were examined. The mammary glands treated locally with saline showed little, if any, lobulo-alveolar development, whereas the mammary glands treated with relaxin showed not only marked lobulo-alveolar development but also prominent secretions in the alveoli. The saline-treated glands were characterized by relatively dense and highly organized collagen fiber bundles. Whereas, in the relaxin-treated mammary glands, collagen fiber bundles were dispersed and loosely organized. In conclusion, relaxin-binding sites in the mammary gland are functional relaxin receptors and relaxin acts directly on the pig mammary gland to promote development of the alveoli and remodeling of the extracellular matrix.

• Applied Microscopy
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• v.29 no.2
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• pp.137-147
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• 1999

Comparative differences between the fine structure of cultured LL/2 cell in vitro and tumor cells in vivo which were induced in the lung by inoculation of LL/2 cells to C57 BL/6 mouse via tail vein during 21 days are not observed except for cell configuration which was changed spindle shape into oval shape. At first tumor cells appeared at lymphatic nodules and around capillary in the lung. Tumor cells divided actively by mitosis, so they became tumor nodules. The pulmonary aveoli around tumor nodules were observed somewhat flattened in shape but the cells in the aveoli appeared to be in normal condition. Furthermore the normal lung cells were observed in the tumor nodules and some apoptotic tumor cells appeared in the large tumor nodules. A lot of neutropiles were observed in the aveoli and tumor nodules of C57 BL/6 mouse lung after inoculation 22 days and 31days.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.199-203
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• 2008

This study was performed to analyze the characterization of plasma hormonal levels during pregnancy in the Hanwoo recipients pregnant by artificial insemination (AI) or somatic cell nuclear transfer (SCNT) embryos. The synchronized recipients pregnant by SCNT embryos produced by Hanwoo fetal fibroblast cells (n=8) and by AI (control, n=5) were used. The plasma hormonal levels were measured by RIA (P4 and E2) and ELISA (cortisol), respectively. In control, the increase of E2 and the decrease of P4 were occurred immediately before the initiation of parturition. The expression pattern of plasma P4 was similar in both groups from 50 to 10 days before parturition, however, it did not decrease even at the expected date of labor in the SCNT recipients. The plasma cortisol was expressed a lower level during pregnancy in the SCNT recipients. But, the cortisol was increased in the cow aborted around 100 days of pregnancy (n=1). Based on these results, it can be postulated that the failure of the hormonal changes immediately before parturition in the SCNT recipients may be one of the most important reasons for a delayed parturition in clone calving.

• Composites Research
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• v.14 no.3
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• pp.18-31
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• 2001

Interfacial and microfailure properties of the modified steel, carbon and glass fibers/cement composites were investigated using electro-pullout test under tensile and compressive tests with acoustic emission (AE). The hand-sanded steel composite exhibited higher interfacial shear strength (IFSS) than the untreated and even neoalkoxy zirconate (Zr) treated steel fiber composites. This might be due to the enhanced mechanical interlocking, compared to possible hydrogen or covalent bonds. During curing process, the contact resistivity decreased rapidly at the initial stage and then showed a level-off. Comparing to the untreated case, the contact resistivity of either Zr-treated or hand-sanded steel fiber composites increased to the infinity at latter stage. The number of AE signals of hand-sanded steel fiber composite was much more than those of the untreated and Zr-treated cases due to many interlayer failure signals. AE waveforms for pullout and frictional signals of the hand-sanded composite are larger than those of the untreated case. For dual matrix composite (DMC), AE energy and waveform under compressive loading were much higher and larger than those under tensile loading, due to brittle but well-enduring ceramic nature against compressive stress. Vertical multicrack exhibits fur glass fiber composite under tensile test, whereas buckling failure appeared under compressive loading. Electro-micromechanical technique with AE can be used as an efficient nondestructive (NDT) method to evaluate the interfacial and microfailure mechanisms for conductive fibers/brittle and nontransparent cement composites.