• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.425-435
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• 1998

To improve the efficiency of nuclear transplantation in bovine, in this study the development in vitro of nuclear transferred (NT) embryos was compared by different activation regimens of the enucleated oocytes. The effect of developmental stage and culture system of donor nuclei on fusion and development in vitro of NT embryos were also evaluated. Oocytes were collected from Hanwoo ovaries obtained from slaughterhouse and matured in Ham's F-10 supplemented with hormones. After 20~22 h maturation, the oocytes were vortexed to be free from cumulus cells and subsequently their nucleus and the first polar body were removed. Enucleated oocytes were divided into 3 groups for activation; the oocytes of group I were activated with ionomycin for 5 min and subsequently incubated in 6-dimetylarninopurine (DMAP) for 4 h, Those of group II were treated with DMAP for 4 h at 39 h after onset of in vitro maturation (IVM) and those of group III were kept in room temperature ($25^{\circ}C$) for 3 h at 39 h after onset of IVM. After in vitro fertilization (IVF) the embryos for muclear donor were cultured either by group culture (20 embryos /50 ${mu}ell$ drop) or individually (1 embryo /50 ${mu}ell$ drop) for 4 day and 5 day. At day 4 and 5 after IVF, blastomeres were separated in calcium-magnesium free medium, and then classified into small (day 5: $\leq$ 38 ${\mu}{\textrm}{m}$, day 4: $\leq$ 46 ${\mu}{\textrm}{m}$) and large (day 5 : $\geq$ 38 ${\mu}{\textrm}{m}$, day 4 ; $\geq$ 46 ${\mu}{\textrm}{m}$). The separated blastomeres were replaced into enucleated and activated recipient cytoplasm. The blastomere-oocyte complexes were fused by electrically. The NT embryos were cultured in TCM-199 containing 10% FCS in 39$^{\circ}C$, 5% $CO_2$ incubator for 7 day. The results obtained were summarized as follows; There were no differences in fusion and development to blastocyst between groups as group I (68%, 10%), group II (75%, 14%) and group III (73%, 9%), respectively. However, the cell number in blastocyst of NT embryos in group III were significantly fewer than in the other groups (P＜0.05). No differences in fusion and development to blastocyst were found between individual or group cultured and between small or large blastomeres of day 4 and day 5 donor embryos. From these results, it was concluded that the combination of ionomycin and DMAP, or treatment of DMAP at 39 h after onset of IVM were useful for the efficient of production of NT bovine embryos, and the individual cultured embryos could be simply used as donor nuclei for NT bovine embryo.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.15-22
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• 2003

Experiments were conducted to evaluate the effect of blastomere diameters and cell cycle stages on the subsequent development of nuclear transplant rabbit embryos (NT-embryos) using nuclei derived from the 16- or 32-cell stage embryos. All blastomeres and NT-embryos were cultured individually in modified Ham's F-10 medium supplemented with 10% rabbit serum (RS) at $38^{\circ}C$ and 5% $CO_2$ in air. The diameter of blastomeres from 16-cell stage embryos was found twice of those from 32-cell stage (51 vs 27 ${\mu}m$). Significant differences were observed in cleavage rates ($\geq$3 divisions) in the isolated single blastomeres (54 vs 48 for 16-cell; 28 vs 14 for 32-cell, p<0.05), but the fusion rates of oocytes with transferred nuclei were similar between small and large single blastomeres derived from either 16-cell or 32-cell stage embryos. When 16-cell stage blastomeres were used as nuclear donors, cleavage rates ($\geq$3 divisions) of the NT-embryos were greater in the small nuclear donors than in the large donors (73 vs 55%, p<0.05). On the contrary, significantly higher cleavage (43 vs 6%, p<0.05) and developmental rates (14 vs 0%, p<0.05) were observed in the large blastomere nuclear donor group of the 32-cell stage embryos. When the cell cycle stages were controlled by a microtubule polymerization inhibitor (Demicolcine, DEM) or the combined treatment of DEM and Aphidicolin (APH), a DNA polymerase inhibitor, fusion rates were 88-96% for the 16-cell donor group (without DEM treatment), which were greater than the 32-cell donor group (54-58%). Cleavage rates were also greater in the transplants derived from G1 nuclear donor group (93-95%) than those from the DEM and APH combined treatment (73%) for the 16-cell donor group (p<0.05). No significant difference was detected in the morula/blastocyst rates in either donor cell stage (p>0.05). In conclusion, it appeared that no difference in the developmental competence between large and small isolated blastomeres was observed. When smaller 16-cell stage blastomeres were used as nuclear donor, the cleavage rate or development of NT-embryos was improved and was compromised when 32-cell stage blastomeres were used. Therefore, control nuclear stage of the donor cell at $G_1$ phase in preactivated nuclear recipients seemed to be beneficial for the cleavage rate of the reconstructed embryo in the 16-cell transplant, but not for subsequent morula or blastocyst development.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.1
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• pp.38-45
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• 2006

Movement of nitrate ($NO_3-N$) through a soil profile under no tillage (NT) or conventional tillage (CT) practices was monitored to identify the effects of tillage systems on nitrate leaching and retention in the soil profile at two commercial farms in central Illinois from 1993 through 1994. Anhydrous ammonia was applied in the 1993 growing seasons, while a mixture of urea and ammonium nitrate solution (URAN) was applied in three separate applications during the spring and early summer of the 1994 season. $NO_3-N$ of each plot through a 100 cm soil depth was found to be significantly high around $20mg\;kg^{-1}$ soil in the early 1993 season. However, downward movement of $NO_3-N$ occurred during the growing season. At the end of growing season, Flanagan and Ipava soils generally retained more $NO_3-N$ through the soil profile for both the CT plots and the NT plots than the Saybrook and Catlin soils. However, there was no significant difference between the nitrate content of the two soil types in each year. $NO_3-N$ content in NT fields were slightly higher than that observed in CT fields throughout the season before harvest. It means that NT plots may reduce the nitrate leaching to the ground water.

• Journal of Music and Human Behavior
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• v.21 no.1
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• pp.69-87
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• 2024

This study investigated whether joint attention response behaviors in children with autism spectrum disorder (ASD) change in response to musical cues and reinforcing stimulus, and compared them with neurotypically developing (NT) children. The participants included 13 children with ASD and 14 NT children aged between 3 to 5 years. The study established six task conditions, involving cues (verbal vs. musical) for responding to joint attention (RJA) behaviors and reinforcing stimulus (verbal vs. sound vs. musical) for social referencing behaviors. These tasks were presented 12 times with two repetitions each. The results of the study showed that providing musical cues during the RJA phase increased levels of RJA in children with ASD, consistent with prior studies. Subsequently, musical reinforcing stimuli increased the frequency of social referencing behaviors in these children. This indicates that musical stimuli can extend beyond mere sensory cues, helping individuals to understand and respond to social and emotional cues from others. Moreover, these musical stimuli could serve as effective social reinforcement factors for this population.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.2
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• pp.76-81
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• 1994

This experiment was carried out to select the best adaptable varieties of Tall fescue in mountainous pastures of Taekwalyon area. The evaluation was based on the data of varietial differences in the dry weight of plant@W) and yield components of the 2nd growth. Nine varieties of Tall fescue examined were Barcel, Barvetia, Demeter, Enforcer, Forager, Fuego, Johnstone, Safe and Stef. And, the final cutting times were Sept. 30 ($C_1$), Oct.14 ($C_2$),Oct. 28 ($C_3$), and Nov. 11($C_4$). The reults were summarized as follows: 1. Barcel and Forager with many tillers per plant(NT) showed a high dry weight of plant@W) of the 2nd growth. 2. The dry weight of plant(DW) of the 2nd growth indicated significantly positive correlation with the number of tillers per plant(NT), but there was not significant correlation with the dry weight of tiller(WT). 3. The maximum dry weight of plant@W) of the 2nd growth was obtained at $C_3$(28 Oct.). 4. The dry weight of the 2nd growth showed an inverse relations with the dry weight of the 1st growth as affected by various final cutting time in growth period of autumn.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.27-30
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• 1998

본 논문에서의 기존의 2선식 댁내 망을 이용하여 ISDN PRI(2.048MHz)급의 전송을 위해 DS-CDMA방식을 적용하는 방법을 제안한다. TE 와 NT 의 신호의 검출을 위해 자기의 확산코드와 정합된 단일 사용자 검출기를 사용할 수 있으나, 검출하려는 신호와 다른 사용자 신호간의 다원접속간섭(Multiple Access Interference)에 의해 시스템의 성능이 저하된다. 본 논문에서는 다원접속간섭을 효과적으로 제거할 수 있는 최소평균제곱오차 (Minimum Mean Squared Error) 다중사용자 간섭제거기를 사용하고 컴퓨터 모의실험을 통하여 성능을 분석한다.

• Biomedical Science Letters
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• v.6 no.1
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• pp.11-17
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• 2000

SNAP-25 was first investigated as a neuron-specific protein preferentially expressed in CA3 pyramidal neurons of mouse hippocampus. It is a presynaptic plasma membrane protein in the nerve cell and plays an important role in the synaptic vesicle membrane docking and fusion pathway. We have recently isolated SNAP-25 cDNA from a rat brain cDNA library using a probe of Z2 cDNA. It consisted of 2,101 bp and an open reading frame (ORF) was identified between nucleotides (nt) 209 and 827. The AUG codon (nt 209∼211) was surrounded by CTACCATGG, which corresponded to the consensus sequence of ribosomal binding site. The ORF was terminated by TAA (nt 827∼829) to encode a polypeptide of 206 amino acid residues. The 3'-untranslated region contained two extensive stretches of repeated (CA)28 and (CA)19 at positions 925∼980 and 1645∼1682. It is noteworthy that cysteine residues were clustered in the span of amino acid residues 84∼991 : Cys-Gly-Leu-Cys-Val-Cys-Pro-Cys. Rat SNAP-25 showed 88% and 97% identity in nucleotide sequences to that of human and mouse, respectively. Amino acid sequence of rat SNAP-25 showed 100% identity to that of mouse and human SNAP-21.

• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.313-326
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• 2006

본 연구는 중학교 2학년 141명의 학생을 대상으로 수학 창의성(Mathematical Creative Problem Solving Ability Test: KEDI, 1997)과 성격유형(Murphy-Meisgeier Type Indicator for Children: 심혜숙 김정택, 1993)과의 상관관계를 조사하였다. 자료 분석은 중학생의 성격 특성을 알아보기 위하여 유형별로 빈도와 백분율을 산출하였고, 성격유형에 따른 수학 창의성의 차이를 검증하기 위하여 평한, 표준편차, t-test, ANOVA와 Duncan 사후검증을 실시하였다. 본 연구 결과는 다음과 같다. 첫 번째, 일반 중학교 2학년과 비교해 볼 때, 선호지표에서 연구 집단의 중학생은 표준화집단(심혜숙 김정택, 1993)보다 I(2.7%), J(3.9%)가 높았다. 두 번째, 수학 창의성과 성격유형을 살펴본 결과, 기질적 측면에서 유창성, 융통성, 수학 창의성 전체에서 NF형이 SJ, SP형에 비해 의미 있게 높았고, SJ형도 SP형에 비해 의미 있게 높게 나타났다. 세 번째, 성격유형 중에서 어떤 요인이 중학교 2학년의 수학 창의성을 잘 예측해 주는지를 살펴본 결과, 직관(N), 내향(I)이 수학 창의성의 예인변인으로서 유의하였다. 이러한 결과와 관련하여 수학 창의성 검사도구 및 수학창의성 프로그램 개발 시 직관과 내향을 우선적으로 고려하여야 한다. 네 번째 NT와 {SP, SJ, NF}는 통계적으로 유의미하게 같은 수준의 집단이 아니므로 직관적사고형(NT)이 감각적 감정형(SF), 감각적 사고형(ST), 직관적 감정형(NF)과는 독립된 특별한 요인으로 보인다. 직관적사고형(NT)은 조사와 개념 학습이나 소크라테스식의 문답법적인 학습과 문제해결학습을 선호하고 독립심이 지지되는 분위기의 학급을 선호한다. 따라서 수학 창의성 증진과 관련된 교육과정이나 프로그램개발 시 조사와 개념 학습이나 소크라테스식의 문답법적인 학습과 문제해결학습을 우선적으로 고려하여야 할 것이다. 연구 결과와 관련하여 연구의 제한점과 후속연구를 위한 제언은 다음과 같다. 첫째, 연구대상이 특정지역의 중학교 2학년 학생이므로 연구결과를 우리나라 중학교 2학년으로 일반화시키는데는 무리가 있을 수 있다. 따라서 후속연구에서는 연구대상의 표집을 확대하여 볼 필요가 있다. 둘째, 수학 창의성과 성격유형간의 관계와 관련하여 수학 창의성과 성격유형의 각 하위 차원들 간에 적률 상관계수를 통해 상관관계를 분석해 보는 것이 필요하다. 셋째 직관과 내향 및 조사와 개념 학승이나 소크라테스식의 문답법적인 학습과 문제해결학습을 고려한 수학 창의성 프로그램이 개발할 필요가 있다.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.175-180
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• 2006

This study was conducted to examine the effect of pre activation treatment and activation time of recipient cytoplasm on the development of bovine somatic cell nuclear transfer(NT) embryos. Donor cells were transferred and electrofused to enucleated oocytes before(pre-AC) or after activation(post-AC). Activation was induced with a combination of $Ca^{2+}$-ionophore(A23187) and DMAP. NT embryos were cultured in CR1aa containing 3 mg/ml BSA for 9 days. Some NT embryos were fixed at 0.5 to 2.5 hr after fusion(for post-AC) or activation(for pre-AC) for confocal microscopy. Developmental rate to the blastocyst stage was slightly high in the post-AC group(20.6%) compared to that of pre-AC group(15.3%). However, developmental speed of embryos in the pre-AC group was faster than that of embryos in the post-AC group. Development rates to the blastocyst stage were similar among different activation time before fusion(0.5,2 and 4 hr). The result of the present study suggests that development and nuclear morphology are affected f the activation status of the recipient cytoplasm before fusion.

• Journal of Embryo Transfer
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• v.29 no.2
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• pp.111-117
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• 2014

This study was conducted to optimize the efficiency of cloning and to produce cloned mice. The majority of cloned mammals derived by nuclear transfer (NT) die during gestation and have enlarged and dysfunctional placentas. In this study, the optimized conditions were established to produce clone mice. The parthenogenetic oocytes were activated after 6 h regardless of cytochalasin B (CB) concentration. CB treatment ($2{\mu}g/ml$) was found second polar body. Lower concentration of CB was decreased the activation rate, but the second polar body was the best highly increased during 6 h incubation. The small fragments were exhibited in the $5{\mu}g/ml$ treatment of CB, but it was not found in lower concentration groups (> $2.5{\mu}g/ml$). To examine effects of $SrCl_2$ on the adult cumulus cells, somatic cell NT oocytes were exposed during 0.5, 1 and 6 hrs. The second polar body was significantly greater in 0.5 h exposure group (6.6%) than 1, 6 hrs. Developmental rate from 2-cell to 4-cell was the lowest in 7.5 mM Strontium chloride ($SrCl_2$) groups (84.1% and 64.3%) than 5, 10 m $MSrCl_2$. The implantation rate was not significantly difference among 5, 7.5 and 10 m $MSrCl_2$ group. Three live fetuses were produced by SCNT. SCNT placentas were remarkably heavier than IVF group (8 fetuses) (0.34, 0.34, 0.33 vs 0.14 g) compared with the placenta weight of IVF and SCNT clones.