• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1282-1290
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• 2010

The study was carried out to assess the developmental abnormalities induced by Cytotec in mice during intrauterine life. Pregnant mice were exposed to a single dose of 0, 0.02, 0.04, 0.06, 0.08 and $0.1{\mu}g$/g BW on day 8 of gestation. Fetuses were recovered on day 18 of gestation. These fetuses were subjected to morphological and morphometric studies. Morphological studies showed abnormalities like anophthalmia, microophthalmia, micromelia and syndactyly. In addition to these, resorptions were also encountered in the higher dose groups. Morphometric analysis showed an overall reduction in body weight, crown rump length, brain and eye circumference, pinna and snout size, length of fore and hind limb and tail size with a significant difference (p<0.001) compared to controls. The outcomes of histological studies revealed some brain defects like hydrocephaly, enlarged third ventricle and undifferentiated ectoneural cells and abnormalities of the heart included right auricle thrombosis and degeneration of trabecular zone.

• Journal of the korean academy of Pediatric Dentistry
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• v.3 no.1
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• pp.48-51
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• 1976

Surveying the developmental degree of the crowns of mandibular first bicuspid in 566 korean children (264 males and 302 females) from 3 to 7 years of age by oblique cephalogram, the author got to the following results. 1. The developmental degree of the tooth crown of mandibular first bicuspid was earlier in female than in male. 2. The period of complete development of the crown of mandibular first bicuspid was 7 year 1 month in male and 6 year 3 month in female. 3. There was no significant difference in the period of complete development of the tooth crown compared with that of Japanese and American children.

• Phonetics and Speech Sciences
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• v.3 no.3
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• pp.11-18
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• 2011

This paper examines the categorical labeling of lexical pitch accent contrasts in North Kyungsang and South Cholla Korean listeners. It focuses specifically on investigating whether the pitch accent perception of adults and children has a dialect-specific effect. To evaluate the development of perceptual identification, slopes, intercepts, and positions at categorical boundaries were computed using a logistic regression function. The results showed that differences in slopes and intercepts were significant between North Kyungsang child and adult listeners, but the same was not the case for the positions at boundaries. As far as South Cholla child and adult listeners were concerned, there was a significant difference in slopes, but not intercepts and positions at boundaries. In the present study, the comparison of intercepts and slopes at the boundaries indicated developmental differences between North Kyungsang adult and child listeners. This improvement in categorical proportion seems to be a result of developmental changes in categorical perception. For South Cholla adult and child listeners, however, perception of the non-native contrast becomes less categorical.

• Korean Journal of Child Studies
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• v.27 no.1
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• pp.113-124
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• 2006

Korean children reading Hangul was studied in children between 2 and 5 years of age. Subjects were 400 young children in each age group from kindergartens or day care centers in 6 cities of Jeon-buk Province. Teachers used a checklist based on Lee, Cha-Suk(2003) to assess children's reading ability. Data were analyzed by frequency, percentage, and $x^2$ using SPSS 10.0 program. Results showed age differences in young children's reading of Hangul. Developmental levels consisted of looking at pictures because of absence of linguistic awareness about words, skipping pages of text without pictures, pronouncing phonemes, being aware of phonemes and of the difference between pictures and print, and knowing that the same phonemes can be applied to different words.

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.325-330
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• 2007

Recognizing the ecological importance of forest gap formation for forest community structure, we examined the differences in species diversity between forest gaps and closed canopy areas for trees and shrubs in three developmental stages (seedling, sapling I, and sapling II) in a typical mixed broadleaved-Korean pine forest. We randomly placed 100 sample plots ($2{\times}2m$ for seedling and sapling I, and $5{\times}5m$ for sapling II) in forest gap and closed canopy areas of a 9 ha permanent sample plot for vegetation surveys of plants of each developmental stage in each habitat type. Even though the formation of forest gaps encouraged the occurrence of gap-dependent species and increased overall species diversity, there were no significant differences in species richness among the three developmental stages for both tree and shrub species (p>0.05). Comparing the two types of sites, statistical tests revealed no difference in species richness for trees, but highly significant differences (p<0.01) between forest types for shrubs for seedlings and sapling I, but not sapling II. Analysis of variance test indicated that there were no significant differences in species diversity among the three developmental stages of tree species (p>0.05) for both Simpson and Shannon indices. The variance for shrub seedlings was significantly different between forest gaps and closed canopy areas, but not for sapling I and sapling II. The analysis showed that the species diversity in forest gaps was significantly different from that of closed canopy areas for seedling and sapling I (p<0.01), but not for sapling II (p>0.05).

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.105-113
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• 2011

The present study investigated the nuclear remodeling, development potential with telomerase activity and transcription level of X-linked genes (ANT3, HPRT, MeCP2, RPS4X, XIAP, XIST and ZFX) in the bovine somatic cell nuclear transfer (SCNT) embryos using two different fusion and activation methods. Female adult fibroblasts were injected into perivitelline space of in vitro matured oocytes. The oocyte-nucleus complexes were fused and followed by immediately either activated (Group 1), or activated at 1 h post-fusion (hpf) (Group 2), respectively. The incidence of normal premature chromosome condensation (PCC) at 1 hpf was slightly increased in the Group 2, compared to those of Group 1, but there was no significant (p<0.05) difference. The incidence of normal pronucleus (PN) and chromosome spread at 5 and 18 hpf were significantly (p<0.05) higher in the Group 2 than those of Group 1. The cleavage rate to 2-cell stage, developmental rate to blastocyst stage, and the mean number of total and ICM cell numbers were significantly (p<0.05) higher in the Group 2, compared to those of Group 1. Level of telomerase activity was significantly (p<0.05) higher in the SCNT blastocysts of Group 2, compared to those of Group 1. Transcript levels of HPRT, MeCP2 and XIST were not significantly (p<0.05) different between blastocysts of Group 1 and 2. However, transcript level of ANT3, RPS4X, XIAP and ZFX were significantly (p<0.05) up-regulated in the SCNT blastocysts of Group 2, compared to those of Group 1. Taken together, it is concluded that oocyte activation at 1 hpf induces the enhanced developmental potential by efficient nuclear remodeling and subsequent facilitation of the nuclear reprogramming of bovine SCNT embryos.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.3
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• pp.223-231
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• 2020

Karyotype analysis is a major work in the process of triploid abalone production for the purpose of productivity and quality improvement. However, the metaphase spreads for karyotype analysis have been prepared just from the larvae at trochophore stage, which has restricted the spectrum of sample correction inhibiting more efficient analysis. Here, we investigated the feasibility of preparing metaphase spreads from the larvae at veliger stage that is the next developmental stage of trochophore. For this, diploid and triploid larvae at trochophore and veliger stages from Pacific abalone (Haliotis discus hannai) were subjected to metaphase spread preparation and its efficiencies were measured and compared each other. As the results, although the efficiencies of metaphase spread preparation were significantly lower in the larvae at veliger stage compared to the ones at trochophore stage regardless of ploidy status, we found that the preparation of metaphase spreads, which showed the clear chromosomal images containing the normal number of chromosomes, was possible from the veliger stage larvae. On the other hands, all larvae used in this study regardless of developmental stage and ploidy did not show colchicine sensitivity. Moreover, no significant difference was observed in cell cycle distribution of the cells comprising larvae between two developmental stages regardless of ploidy status. These suggested that the details of protocol to prepare metaphase spreads from abalone larvae should be optimized depending on its developmental stages. Taken together, we demonstrated the feasibility of preparing metaphase spreads from H. discus hannai veliger stage larvae for karyotype analysis.

• Development and Reproduction
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• v.5 no.2
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• pp.101-106
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• 2001

Present study was aimed to verify the role of insulin and TNF-$\alpha$ in development of preimplantation embryos. Mouse morula were cultured for 40 hr in the presence or absence of insulin(400 ng/ml) and TNF-$\alpha$ (50 ng/ml). The morphological development, cell number of blastomeres per blastocyst, and mitogen activated protein kinase(MAPK) activity were examined. The developmental rate and cell number per embryo were the highest in insulin treatment group and the lowest in TNF-$\alpha$ treatment group. There was no significant difference in developmental rate between control and insulin plus TNF-$\alpha$ group. Taken together, it suggested that TNF-$\alpha$ impaired embryonic development and that insulin rescued developmental impairment imposed by TNF-$\alpha$. In blastocysts, insulin treatment significantly increased MAPK activity. TNF-$\alpha$ decreased the MAPK activity in a concentration-dependent manner. In the TNF-$\alpha$(50 ng/ml) -primed embryos, activation of MAPK by insulin was attenuated. In conclusion, these results suggest that there was a cross talk between insulin and TNF-$\alpha$ by means of activation of MAPK in preimplantation embryos and that insulin might rescue damage of embryos exposed to TNF-$\alpha$.

• Journal of Embryo Transfer
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• v.24 no.2
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• pp.115-119
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• 2009

In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrifiedthawed porcine oocytes were examined. Oocytes were cultured in TCM-199 medium supplemented with 5% FBS at $38^{\circ}$C in 5% $C0_2$ and air. The percentage of monospermy in the toxicity group and vitrification group (22.0 ${\pm}$ 3.0% and 31.5 ${\pm}$ 3.5%) was decreased compared with that of the control group (44.0 ${\pm}$ 4.0%). The percentage of in vitro development to blastocyst in the toxicity group and vitrification group (12.0 ${\pm}$ 2.5% and 14.8 ${\pm}$ 2.8%) was decreased compared with that of the control group (28.0 ${\pm}$ 3.0%, p<0.05). The survival and in vitro developmental rate of oocytes vitrification-thawed with EDS and EDT + TCM-199 medium supplemented with 0.1% PVA were 46.3 ${\pm}$ 3.0%, 54.5 ${\pm}$ 3.8% and 14.8 ${\pm}$ 2.5%, 16.4 ${\pm}$ 2.7%, respectively. This results were lower than the control group (28.0 ${\pm}$ 3.5%). The in vitro developmental rate of embryos vitrified with EDS and EDT supplemented PVA did not have a significant difference. The survival and in vitro developmental rate of vitrified-thawed morula and blastocyst embryos were 44.2 ${\pm}$ 3.5%, 17.3 ${\pm}$ 3.0% and 48.1 ${\pm}$ 4.2%, 18.5 ${\pm}$ 3.5%, respectively. Vitrified morulae and blastcyst embryos had a lower survival and developmental rates than their control counterparts.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.653-658
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• 2016

This investigation aimed to evaluate the differential expression of HoxB7 and notch genes in different developmental stages of Echinococcus granulosus sensu stricto. The expression of HoxB7 gene was observed at all developmental stages. Nevertheless, significant fold differences in the expression level was documented in the juvenile worm with 3 or more proglottids, the germinal layer from infected sheep, and the adult worm from an experimentally infected dog. The notch gene was expressed at all developmental stages of E. granulosus; however, the fold difference was significantly increased at the microcysts in monophasic culture medium and the germinal layer of infected sheep in comparison with other stages. The findings demonstrated that the 2 aforementioned genes evaluated in the present study were differentially expressed at different developmental stages of the parasite and may contribute to some important biological processes of E. granulosus.