• Development and Reproduction
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• v.9 no.2
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• pp.95-103
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• 2005

Reproductive cycle, gonadosomatic index(GSI), egg diameter composition, first sexual maturity, sexually matured length(50% of first sexual maturity), and sex ratio of Amusium japonicum japonicum, were investigated by histological observations and morphometric data. Samples were collected monthly from the subtidal zone of Sogwipo, Jejudo, Korea, for two years. The sun and moon scallop Amusium japonicum japonicum is dioecious. Monthly variation in the GSI showed similar patterns with the reproductive cycle. Ripe oocytes were about $70{\sim}90\;{\mu}m$ in diameter and had thick egg membranes. The spawning period was from November to January, and the main spawning occurred between November and December when the seawater temperature was relatively low. From monthly changes in egg diameter composition, the spawning period was once a year, although the number of spawning frequencies is assumed to occur more than twice during the spawning season. The reproductive cycle of this species could be divided into five successive stages: early active stage(April to June), late active stage(June to September), ripe stage(October to November), spawning stage(November to January), and spent/resting stage(February to April). First sexual maturities in female and male scallops ranging from 85.1 to 90.0mm in shell length were over 50% and they were 100% for scallops over 90.0mm in shell length. In this population, sexually matured shell lengths(50% of rate of group maturity) in females and males were 86.96 and 86.59mm, respectively. The female to male sex ratio among individuals over 85.1mm in shell length was not significantly different from 1:1($X^2=0.18$, p>0.05). No evidence of hermaphrodite was found in histological sections of any scallop examined.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.2
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• pp.85-89
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• 2017

Objective: The aim of this study was to explore the effects of the insemination method on the outcomes of elective blastocyst culture. Methods: We retrospectively analyzed the outcomes of elective blastocyst culture performed between January 2011 and December 2014. Results: There were 2,003 cycles of conventional in vitro fertilization (IVF) and 336 cycles of intracytoplasmic sperm injection (ICSI), including 25,652 and 4,164 embryos that underwent sequential blastocyst culture, respectively. No significant differences were found in the female patients' age, basal follicle-stimulating hormone level, basal luteinizing hormone level, body mass index, number of oocytes, maturity rate, fertilization rate, or good-quality embryo rate. However, the blastocyst formation rate and embryo utilization rate were significantly higher in the conventional IVF group than in the ICSI group (54.70% vs. 50.94% and 51.09% vs. 47.65%, respectively, p<0.05). The implantation/pregnancy rate (IVF, 50.93%; ICSI, 55.10%), miscarriage rate (IVF, 12.57%; ICSI, 16.29%), and live birth rate (IVF, 42.12%; ICSI, 44.08%) were similar (p>0.05). No cycles were canceled due to the formation of no usable blastocysts. Conclusion: Although the fertilization method had no effect on clinical outcomes, the blastocyst formation rate and embryo utilization rate in the ICSI group were significantly lower than those observed in the conventional IVF group. Therefore, more care should be taken when choosing to perform blastocyst culture in ICSI patients.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.2
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• pp.128-135
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• 1984

Gamadi, a native rice cultivar from Nepal in which the panicle remains enclosed within its flag leaf sheath upto maturity, was crossed with different genetic marker testers of 12 linkage groups in order to analyze its linkage relationship. The results obtained from the experiment were summarized as follows: Normal segregations of all the genetic marker genes used in this experiment viz Cl, wx and Pla of linkage group I, Pn, Rd and Pub of linkage group III, and lg, g, Ps, gh, Hla, la, nl, bl, be and gl of linkage groups II, IV, V, VI, VII, VIII, IX, X, XI, and XII respectively confirmed the previous results, and also strongly indicated that the genetic constituent of the Gamadi and marker testers is same. 'Gamadiness' (the panicle enclosing character) was controlled by two complementary dominant genes with the segregation ratio of 9 Gamadi to 7 normal panicle-exserting types. These genes have been temporarily proposed as G-a and G-b for gamadiness. G-a gene was found to be linked with the neckleaf gene (nl) of linkage group Ⅸ with the crossover value of 0.3733$\pm$0.027. G-b gene appeared to be associated with the brittle culm gene (bc) of the linkage group XI with the crossover value of 0.2725$\pm$0.061.TEX>0.061.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.315-323
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• 2005

For reconstruction of the bony defect, distraction osteogenesis has many advantages in comparison with bone graft. However, it needs long consolidation period for sufficient bone maturity. This study is performed to evaluate the effect of PRP injection into the distracted mandible on bone formation in rabbits. Twelve house rabbits, weighing 2 kg, were used. All animals underwent bilateral mandibular osteotomy under general anesthesia. A internal distractor divice was positioned along a plane perpendicular to the line of osteotomy. After 5 days of latency period, distraction osteogenesis was started at a rate of 1 mm/day for 9 days which was distracted 9 mm totally. After completion of distraction, 0.5 ml of PRP which collected in rabbit blood was injected into the distracted mandible on experimental group, whereas no injection was done in control group. Macroscopical, radiographical, and histological, and histomorphometric examinations were performed 2, 4 and 8 weeks after distraction. All animals showed distracted mandible and severe anterior cross-bite. In radiographical findings 2 weeks after distraction, more radiopacity in the distracted gap was found in experimental group than that of control group. At 4 weeks after distraction, distracted bone was similar to normal bone in experimental group. In histological findings, 1) At 2 weeks after distraction, number of osteoblasts and angiogenesis in the distracted gap was found in experimental group than that of control group. 2) At 4 weeks after distraction, more active and distinct bone in the distracted gap was found in experimental group than that of control groups. 3) At 8 weeks after distraction, more dense and matured lamellated bone in the distracted gap was found in experimental group than that of control group. In histomorphometrical findings 8 weeks after distraction, more bone formation was observed in experimental group than control group (p<0.01). These results indicate that administration of PRP into the distracted mandible can promote bone formation.

• Journal of Animal Science and Technology
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• v.54 no.6
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• pp.395-400
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• 2012

This study was conducted to estimate the growth curve parameters for the body weight (BW) and body length (BL) of miniature pigs in Korea. Growth curve parameters were estimated through a nonlinear regression model using Gompertz, Logistic, and von Bertalanffy methods. A total of 25 piglets were measured monthly from birth up to 15 months of age to estimate both body weight and length. Results showed that the estimated average values for the body weight (body length) were 31.83 kg (58.77 cm) for the mature weight (A), 3.06 (1.74) for the growth ratio (${\beta}$), and 0.28 (0.52) for the maturing rate (${\kappa}$). Average inflection points showing maximum growth rate estimated each month for body weight were 3.97 kg and 11.70 cm, while for the body length were 1.06 kg and 21.61 cm. Moreover, the estimated maturation rates of the body weight and length for the group of Sire 1 were 0.22 and 0.40 respectively, whereas for the group of Sire 2 these values were 0.34 and 0.39. On the other hand, for the groups of Dam 1, Dam 2, and Dam 3, maturation rates for their body weights were 0.26, 0.28 and 0.33 respectively, while for their body lengths these values were 0.43, 0.37, and 0.38, respectively. The study also indicated a negative relationship between the values of mature weight and maturity rate for the body weight will result to a higher inflection point which is in contrast for the body length where results show that a positive relationship between the values of mature length and the maturity rate will result to a higher inflection point. Furthermore, the growth performance of miniature pig varies across stages but using these estimated growth curve parameters could improve the genetic traits of miniature pig.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.171-178
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• 2015

The reproductive ecology of freshwater bivalve, Unio douglasiae in Lake Uiam were examined from March 2014 to February 2015. The gonads distributed in reticular connective tissue, the dioecious clams take an internal fertilization and fertilized eggs are stored in the foster-sack in the gills, then the hatched juveniles are released outside after an ovoviviparous process. The gonad index (GI) began to increase in April, reached the maximum value in July and to decrease in August. The reproductive cycle of U. douglasiae can be divided into five successive stages: multiplicative stage (November to January), growing stage (February to March), mature stage (February to May), spawning stage (April to September), recovery stage (August to December). The spawning periods were from April to September, and the main spawning occurred between April and July. The shell length at 50% group maturity was estimated to be 29.4 mm.

• The Korean Journal of Malacology
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• v.22 no.2
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• pp.175-182
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• 2006

Artificial induction of maturation by heating of the ark shell, Scapharca broughtonii (Schrenck) broodstock was investigated from 10th March to 21th May in 2004. Maturity at the fixed water temperature group of $23^{\circ}C$ was 60.5％, and it was the highest in maturity among experimental groups cultured for seven weeks. The proportions of organism surviving to start of S. broughtonii in the raised water temperature experimental groups (20 and $23^{\circ}C$) were over 90.5％, as similar to the control group (natural water temperature, 84.8％). But, the proportions of organism surviving to start of S. broughtonii in the fixed water temperature experimental groups (20, 23, and $26^{\circ}C$) were decreased with the increasing of the water temperature. In the fixed water temperature experimental groups of $26^{\circ}C$, the survival was 18.1％. Base on these results, the fixed water temperature of $20^{\circ}C$ (accumulated water temperature; $1,295^{\circ}C$) was the best condition for artificial induction of sexual maturation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.161-169
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• 2005

With various Korean domestic soybeans, growth and yields analysis were conducted to select the suitable soybean cultivars for cultivation in paddy field. Distinctive aspects of the soybean growth were observed in paddy field such as retarded growth of top plants and roots, relatively higher T/R ratio followed by overgrowth of top plant. However, growth and yields were significantly different among the cultivars showing 134kg/10a in Paldokong and 385 kg/10a in Doremikong. At V5. and R2 stage, highly positive correlations $(r=0.76^{**}\~0.91^{**})$ were observed between leaf area and dry weight of top plant and/or root. T/R ratio was negatively correlated with dry weight of root $(r=-0.37^*)$ at V5 stage, while significantly correlated with leaf area $(r=-0.37^{**})$ and dry weight of top plant $(r=0.65^{**})$at R2 stage. Among the characters, only 100-seed weight was significantly correlated with yield. Considering the growth characters, 37 cultivars could be included in 3 different groups and genotypic properties such as maturity and growth habit were similar in each group. Nine cultivars in group 1 showed retarded growth from V5 to R2 stage, relatively lower T/R ratio, and good seed ripening. Average yields of the cultivers was 257kg/10a. In group 2, 12 cultivars showed higher T/R ratio due to overgrowth of top plant and lowest average yields (230 kg/l0a) due to poor seed ripening. Sixteen cultivars in group 3 grew fast from V5 to R2 stage representing late maturity traits, low T/R ratio, and good seed ripening. Average yields of the cultivars was highest among groups showing 270kg/l0a. In results, stable self-sufficiency of soybean yields could be expected by selective cultivation with high yielding cultivars ranging from 301 to 385kg/10a, such as Shinpaldalkong 2, Sohokong, Doremikong, Keumkangkong, Bukangkong, Dajangkong, and Geomjeongkong 2, or with cultivars included in group 3.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.952-959
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• 2010

This study was conducted to evaluate growth, behavior and carcass traits of fattening Hanwoo (Korean native cattle) steers managed in different group sizes. A total of 48 animals, 6 months of age, were allocated to one of three group sizes and the experiment was conducted from 12 to 30 months of age. Groups were balanced for weight and the group sizes consisted of 4, 8, or 12 steers which were named 4sG, 8sG and 12sG, respectively. When animals were 12 months of age, initial fasted body weight (BW, $304.51{\pm}12.40\;kg$) was measured. All animals were housed at a constant space allowance of $8.82\;m^2$ per animal, and a feeder and drinker were provided per 4 animals. The whole fattening stage was divided into three phases: phase I (from 12 to 18 month of age), phase II (from 19 to 24 month of age), and phase III (from 25 to 30 month of age). Steers managed in 12sG showed low (p<0.05) growth rate and feed conversion rate (FCR) in phase I and phase II when compared to other treatment groups. However, this difference was not observed for the whole fattening phase (p>0.05). Steers managed in 4sG had a thick (p<0.05) ultrasound back fat thickness at 15 and 18 months of age. However, group size had no effect on meat yield and quality traits of area and marbling score. Animals managed in 8sG yielded a better meat grade of "A" than the "B" grade in other treatment group sizes. Lean color, fat color, firmness and maturity scores did not differ among group sizes. Hanwoo steers housed under 12sG spent less time on eating concentrate, relevant higher eating rate, less frequency of allogrooming, and more time on walking (p<0.05). It could be concluded that a large group size retarded growth rate and back fat thickness in the fattening stage, which was mainly focused on 15 and 18 months of age.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.359-366
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• 2010

It was easy to find that children of a skeletal anterior crossbite in the early mixed dentition period showed a stark difference in the dental maturity between their maxillary and mandibular teeth, if they have stronger physical characteristics. If the difference of dental age between maxillary and mandibular teeth which can be identified via panoramic radiographs may serve as an early sign of class III malocclusion, this is considered valuable as a tool of early detection diagnosis. We obtained lateral cephalometric radiographs, panoramic radiographs, working model and clinical images of patients of Hellman dental age IIA and IIC who visited the department of pediatric dentistry, Pusan National University Dental Hospital and examined them to select 50 patents for normal occlusion group and skeletal anterior crossbite group, respectively. Their panoramic radiographs were used for the Demirjian's method to figure out dental ages of maxillary and mandibular teeth of each group and the eruption rate of the first molars. Their differences are as follows: 1. In both groups, the dental ages from Demirjian's method were advanced than the chronological ages. No sexual dimorphism was detected for the chronological or dental age in either group (p>0.05). 2. The difference of dental age of maxillary and mandibular teeth between the normal occlusion group and crossbite group was 0.22 and 0.69 years, respectively, with a higher difference in crossbite group(p<0.05). 3. Compared to the normal occlusion group, the crossbite group showed a higher difference in the eruption rate between maxillary and mandibular first molar(p<0.05).