• Journal of Embryo Transfer
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• v.23 no.2
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• pp.101-108
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• 2008

This study investigated the developmental ability and gene expression of somatic cell nuclear transfer embryos using ear skin fibroblast cells derived from miniature pig. When miniature pig (m) and landrace pig (p) were used as donor cells, there were no differences in cleavage (79.2 vs. 78.2%) and blastocyst rates (27.4 vs. 29.7%). However, mNT blastocysts showed significantly higher apoptosis rate than that of pNT blastocysts (6.1 vs. 1.7%) (p<0.05). The number of nuclei in pNT blastosysts was significantly higher than that of mNT (35.8 vs. 29.3) (p<0.05). Blastocysts were analyzed using Realtime RT-PCR to determine the expression of Bax-${\alpha}$, Bcl-xl, H19, IGF2, IGF2r and Xist. Bax-${\alpha}$ was higher in mNT blastocyst than pNT blastocyst (p<0.05). There was no difference in Bcl-xl between two NT groups. Bax-${\alpha}$/Bcl-xl was, however, significantly higher in mNT blastocyst compared to pNT. The expression of imprinting genes were aberrant in blastocysts derived from NT compared to in vivo blastocysts. H19 and IGF2r were significantly lower in mNT blastocysts (p<0.05). The expression of IGF2 and Xist was similar in two NT groups. However, imprinting genes were expressed aberrantly in mNT compared to pNT blastocysts. The present results suggest that the NT between donor cells derived from miniature pig and recipient oocytes derived from crossbred pig might affect reprogramming of donor cell, resulting in high apoptosis and aberrant expression patterns of imprinting genes.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.171-176
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• 1998

This study was carried out to confirm whether the in vivo developmental potential of mouse hatched blastocysts (HBs) can be obtained by vitrification method using the cryoprotectant EFS35. The HBs ($\theta$ 130$\mu\textrm{m}$) were cultured in vitro until day 5 from zygotes produced in vivo and were equilibrated in 10% ethylene glycol(EG) for 5 min, and then were exposed or vitrified in EFS35 (35% EG, 18% Ficoll and 0.3M sucrose). After 30 min thawing, re-expanding HBs were transferred into one or both uterine horns of pseudopregnant recipients on day 3 (4~6 embryos /horn). Pregnancy rates of recipients and implantation were assessed by autopsy on day 15 of gestation. The results obtained in these experiments were summarized as follows : After thaw-ing, in vitro survival of HBs was not significantly different between exposed (65.5%) and vitrified(54.5%) group. Also, when the in vivo development potential was examined, total implantation was not different between control (58.5% ) and vitrified (41.0%) group, although the live fetus formation of vitrified group (24.0%) was significantly lower than that of control (58.3%) group (p< 0.05). These results suggested that vitrification freezing method of mouse HBs using EFS35 can be used to make wide the utility of embryo transfer of the more embryos produced in vitro.

• Reproductive and Developmental Biology
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• v.33 no.4
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• pp.273-281
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• 2009

Antioxidants partially ameliorated the detrimental effects of reactive oxygen species (ROS) on sperm characteristics during in vitro storage. The objective of the present study was to investigate the single or synergetic antioxidative effect of curcumin and Vit. E on the characteristics of fresh boar sperm during in vitro storage. The sperm viability in curcumin, Vit. E supplementation and curcumin+Vit. $E+H_2O_2$ groups remained over 85.0% in 3 hr incubation period, but in 6 hr incubation period, curcumin+Vit. $E+H_2O_2$ groups was sharply dropped than those of curcumin and Vit. E group. The membrane intergrity in all evaluated groups except for $H_2O_2$ group did not significantly difference in 3 hr incubation period. The viability in curcumin or Vit. E supplementation were significantly increased than in curcumin+$H_2O_2$ and Vit. $E+H_2O_2$ group in 6 hr incubation period. The percentage of mitochondrial activity and acrosome intergrity obtained similar trends within same incubation periods irrespective of treatment. The lipid peroxidation of spermatozoal plasma membrane ranged from $11.6{\sim}17.5\;nM/l{\times}10^6$ and $14.0{\sim}19.0\;nM/l{\times}10^6$ in 3 hr and 6 hr incubation periods. In conclusion, curcumin or Vit. E surpplementation alone or cooperatively improved sperm viability index (motility, membrane intergrity, viability and survival rates) and fertility index (mitochondria activity, acrosome intergrity and lipid peroxidation) of fresh boar sperm, indicating that curcumin and Vit. E have a antioxidative properties through its scavenging activity against hydrogen peroxide.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.169-174
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• 2007

Despite many efforts to improving canine in vitro maturation(IVM), the efficiency is still low compared to that of other mammalian species. The present study investigated the effects of gonadotropin, epidermal growth factor and cysteine supplementation on in vitro maturation of canine oocytes. Cumulus-oocyte complexes (COCs) were matured in basic medium (TCM-199 containing 10% FBS, 0.11mg/ml sodium pyruvate supplemented with or without $10{\mu}g/ml$ FSH, 10ng/ml EGF and 0.57mM cysteine) for 72 hr at $38.5^{\circ}C$ in humidified atmosphere of 5% $CO_2$ in air. After culture, oocytes were stained with Hoechst 33342 $(10{\mu}g/ml)$ for 30 min at $4^{\circ}C$, and assessed their nuclear status (GV: germinal vesicle, GVBD: germinal vesicle break down, MI: metaphasse I, MII: metaphase II, UK: unknown stage). No differences were observed in GV, MI and MII rate except GVBD rate between with and without gonadotropins addition respectively (6.7%, vs. 17.2%). Supplementation of 10ng/ml of EGF in hormones added IVM medium resulted in significantly (p<0.05) higher MII rate (4.54% vs.7.06%). Although there are no significantly difference, total of MI and MII rates were increased by adding cysteine. In conclusion, the present study indicates that supplementation of $10{\mu}g/ml$ LH and FSH, 10ng/ml EGF and 0.57mM cysteine in canine IVM medium show a positive influence on the progression of maturation to MII at 72 hr.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.232-240
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• 2018

This study was performed to investigate the effects of water temperature and salinity on the egg development and larval attachment of Ascidiella aspersa. The egg development and larval attachment were examined in 12 different water temperatures (6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26 and $28^{\circ}C$) and two salinity conditions(30 and 34 psu). The hatching and developmental rates of A. aspersa showed a tendency to increase with increasing water temperature regardless of salinity and to decrease after the optimal water temperature range. The optimal water temperatures for the hatching and development of egg of A. aspersa were in the range of $20-22^{\circ}C$. The low threshold water temperature was not different between 1.5 and $1.8^{\circ}C$ at 30 and 34 psu, respectively. The attachment rate showed the optimal water temperature range of $16-22^{\circ}C$ irrespective of the salinity and the attachment time increased continuously with increasing water temperature. Experimental results showed that optimum development and survival temperature of the egg and larvae of A. aspersa were in the range of $20-22^{\circ}C$ regardless of the salinity conditions. The results can be used to predict the distribution and occurrence of A. aspersa, and to prevent economic damages caused by its spread.

• Survey Research
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• v.9 no.2
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• pp.1-27
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• 2008

Problems of incomplete data are pervasive in statistical analysis. In particular, incomplete data have been an important challenge in repeated measures studies. The objective of this study is to give a brief introduction to missing data mechanisms and conventional/recent missing data methods and to assess the performance of various missing data methods under ignorable and non-ignorable missingness mechanisms. Given the inadequate attention to longitudinal studies with missing data, this study applied recent advances in missing data methods to repeated measures models and investigated the performance of various missing data methods, such as FIML (Full Information Maximum Likelihood Estimation) and MICE(Multivariate Imputation by Chained Equations), under MCAR, MAR, and MNAR mechanisms. Overall, the results showed that listwise deletion and mean imputation performed poorly compared to other recommended missing data procedures. The better performance of EM, FIML, and MICE was more noticeable under MAR compared to MCAR. With the non-ignorable missing data, this study showed that missing data methods did not perform well. In particular, this problem was noticeable in slope-related estimates. Therefore, this study suggests that if missing data are suspected to be non-ignorable, developmental research may underestimate true rates of change over the life course. This study also suggests that bias from non-ignorable missing data can be substantially reduced by considering rich information from variables related to missingness.

• Korean journal of applied entomology
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• v.41 no.1
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• pp.55-60
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• 2002

Predation amount and density suppression ability of three species of phytoseiid mites (one native, Amblyseius womersleys Schica; two introduced species, Amblyseius fallacis Garman and Typhlodromus occidentalis Nesbit) on Panonychus citri McGregor were examined in laboratory condition (25$\pm$1$\^{C}$, RH 65$\pm$5%, 16L:8D). A. fallacis and T. occidentalis consumed 20.1 and 9.1 eggs of P. citri, respectively, whereas A. womersleyi consumed 1.1 eggs. When each larva, protonymph and deutonymph of P. citri were supplied as prey for 24 hours. A. womersleyi consumed 23.8, 16.5 and 9.0, and A. fallacis consumed 26.1, 18.2 and 7.4, respectively. However, T. occidentalis consumed only 7.8, 4.2 and 4.2. respectively Density suppression ability of A. womersleyi and A. fallacis against P. citri was very high at the release ratios of 20 : 1 (prey : predator). However, T. occidentalis did not regulate P. citri population effectively Developmental periods from egg to adult of A. womersleyi and A. fallacis was 6.1 and 5.9 days at 25$\^{C}$, respectively.

• Korean journal of applied entomology
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• v.25 no.4 s.69
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• pp.201-207
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• 1986

This study was conducted to investigate the host plants in greenhouse, developmental periods at different temperatures and distribution patterns on cucumber of the greenhouse whitefly, Trialeurodes vaporariorum(TV) in $1984{\sim}1985$. Host plants of 39 species belonging 27 families only in the greenhouse were recorded in 1984. Longevity of adult was 26.8 days and number of eggs per female was 305 eggs at $25^{\circ}C$. The eggs, larval and pupal periods were 8.2, 8.3, 7.5 days respectively at $25^{\circ}C$. The threshold temperature of development from egg to larva was $8.8^{\circ}C$. Survival rates from eggs to adults at $22^{\circ}C,\;25^{\circ}C,\;30^{\circ}C$ were 70.3%, 58.0% and 66.4%, respectively. Adults and eggs were found only on the apical leaves of cucumber plants within 40 days after transplanting. On the other hand, larva distributed on the middle leaves and pupa on the lower leaves.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.385-392
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• 2007

This research was carried out to develop economical artificial diets of the greater wax moth, Galleria mellonella (L.). Diets were mixed with malt or sugar instead of whole honey for cheaper ones. fecundity, developmental period, pupation rate, emergence rate and adult longevity of G. mellonella depending on diet were examined. The head width and length of larvae were not significantly different among diets tested. However, the weight of larva was the heaviest, 255.5 mg, at 1/2 honey + 1/2 malt diet and lightest, 144.3 mg, at sugar diet. The weight of pupa was also the heaviest at 1/2 honey + 1/2 malt representing 196.7 mg. Larval period was the shortest at honey diet as 30.9 days but the longest at sugar diet as 36.5 days. Pupation and emergence rates were over 79.3% at all diets. The longevity of mated females was ranged from 6.3 to 8.0 days and those of mated males ranged from 7.9 to 11.2 days. The highest number of eggs, 1269, was obtained at sugar diet. Artificial diets replaced by rice bran, malt, and sucrose reduced costs compared with wheat bran plus honey diet. The cost of rice bran was only 10% of wheat bran. Honey was much more expensive than malt and sugar, that is 6 and 13 times, respectively.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.371-376
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• 2012

This study was conducted to predict the hatching time of eggs of Lycorma delicatula, to select an effective environmentally-friendly agriculture material (EFAM) and to evaluate the attraction effect of brown sticky traps for controling of Lycorma delicatula nymph and adults. Eggs hatched 55.9, 26.8, 21.6 days after incubation at 15, 20, $25^{\circ}C$ with 14L:10D condition and the hatching rates of egg were 61.9, 57.8, 30.4%, respectively. At high temperature conditions, egg development periods were shorter and the hatching rate was lower. The relationship between temperature and developmental rate was expressed by the linear equation Y=0.0028X-0.0228, $R^2$=0.9561. The low temperature threshold of eggs was $8.14^{\circ}C$ and the thermal constant required to reach larva was 355.4 DD. According to this relationship, the mean estimated hatching date was $22^{nd}$ May. The effective EFAM was natural plant extract, sophora extract, derris extract to nymph and natural plant extract, pyrethrum extract, sophora extract to adult. Among three colors of sticky trap : brown, blue and yellow, the brown sticky trap was the most attractive to nymphs and adults of L. delicatula over a 2 weeks trial period. It suggested that the brown sticky trap could be a very useful and environment-friendly control method for nymphs and adults of L. delicatula.