• Journal of Embryo Transfer
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• v.21 no.2
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• pp.147-156
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• 2006

The objective of this study was to supply excellent genetic resources to livestock farms by transferring embryos produced by genetically superior Korean cows (Hanwoo). Eighty Hanwoo donors were superovulated with gonadotropin ($Folltrpin^(R)\;or\;Antorin^(R)$) for 4 days combined with or without progesterone releasing intravaginal device (CIDR) insertion. The collected fresh or frozen-thawed embryos were transferred to 226 farm recipients. In this study, the effect of CIDR insertion in combination with gonadotropin ($Folltrpin^(R)$) treatments initiated at the random stage of estrous cycle on embryo production was evaluated and compared to conventional superovulation protocol. Moreover, the effect of gonadotropin ($Antorin^(R)$) dose in CIDR-treated Hanwoo donors on the embryo yield was determined. In addition, the effects of embryos (fresh vs. frozen-thawed), embryo transfer person, seasons and farms on the pregnancy rate were evaluated. In Hanwoo donors, CIDR insertion in combination with $Folltrpin^(R)$ treatments regardless of estrous detection resulted in increased numbers of total ova (6.5 vs. 5.8) and transferable embryos (3.9 vs. 3.2) compared to the conventional superovulation protocol (p<0.01). In CIDR-treated Hanwoo donors, the higher dose of $Antorin^(R)$ (36 vs. 28 mg) resulted in the increased number of transferable embryos (8.3 vs. 5.4, p<0.05). The embryos (fresh 43.9% vs. frozen-thawed 23.1%) and embryo transfer person (53.9 vs. $0{\sim}16.7%$) significantly affected the pregnancy rate after embryo transfer (p<0.01). These results suggest that CIDR-based superovulation protocol may be effectively used for production of superior Hanwoo embryos and, multiple ovulation and embryo transfer in Hanwoo might be effectively applied for livestock improvement if pregmancy rate with frozen-thawed embryos and embryo transfer skill would be improved.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.167-175
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• 2016

This study aims to find out the meaning of characters used in science textbooks by analyzing the roles of the characters on the 2009 revised science textbooks and the extracted sentences and see if there are indications referable to compiling future science textbooks by finding out where the characters are efficiently used and where supplement is needed. Target textbooks among those developed for the 2009 revised elementary school science textbooks are the first and second semester of the 4th-grade. Methods used include analysis on the roles of character-containing questions using character role analysis whose illustration analysis frame is more supplemented/adjusted than those used in the foregoing studies, analysis on character-containing questions using the existing analysis frame, analysis/survey on good cases and cases needing supplement through consultation with a science education expert, two teachers, etc. The result shows that among types of character roles, motivation and material provision are more used than experiment guide, experiment, and observation results. Result of analyzing in-textbook characters by field shows that life sphere is more used than free exploration, energy, material, and earth. Result of analyzing question types shows the order of expanding, anticipatory, transferable and personal questions and there were no reminiscent and evaluative questions. Based on the result of this study, indications on how to use in-science textbook characters more efficiently and developmentally are needed.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.90-105
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• 2013

There are lots of variations on speed, acceleration and engine power during vehicle driving. It is well known that Green House Gas emissions by these dynamic driving properties are not precisely estimated by the average speed based emission estimation model which has been currently used in Korea. MOVES are selected as an appropriate transferable model among Micro-level emission estimation models. Based on MOVES, a novel emission estimation model can be used in Korea is developed. In this model, MOVES concept of emission estimation method and the MOVES method of estimating the Micro-level emission rate map is adopted. The results from the proposed model were compared with those from the average speed based emission model. The comparison results show the estimated base emission maps are good to be applied in Korea, but needed to be adjusted to consider the vehicle size differences between the two countries. Therefore, the factors for calibrating vehicle size difference were calculated and applied to acquired the micro-level emission maps for the Korean standard vehicle types.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.191-197
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• 2016

Historically, Korea old cattle had been consisted with various lines of coat color brindle, black and white-brown breeds or more. The two rare lines of black and white coat color are maintained for animal resources and preserved critically. The present study was carried out to evaluate potential usage of cysteamine supplementation during in vitro matration (IVM) and in vitro culture/production of embryo (IVP) by transvaginal ultrasound-guided follicle aspiration (Ovum Pick-Up: OPU) for the establishment of cryo-banking system. Immature slaughterhouse-derived cumulus-oocyte complexes (SL-COCs) were matured in IVM medium supplemented with 0, 0.1, 0.3 or 0.9 mM cysteamine, and then cultured in mSOF-BAS for 8 days after in vitro fertilization. The treatment of 0.1 mM cysteamine on SL-COCs showed higher rate of blastocyst, so OPU-derived COCs from rare breeds were matured in TCM media supplemented with or without 0.1 mM cysteamine, FSH and 5% FBS. The embryos were evaluated their developmental stages on day 8. During IVM, cysteamine treatment significantly increased the embryo production rate of slaughterhouse-derived COCs (19.6% vs. 30.5%). The presence of cysteamine during IVM of OPU-derived COCs from rare Korean cattle breeds (albino white and black line) also increased embryo production rates than those from SL-COCs (27.4% vs. 41.9% and 36.4%). With these results, cysteamine treatment during IVM is one of key factors IVP of blastocysts to establish banking system of endangered rare Koarean cattle with OPU derived transferable blastocysts.

• Journal of The Korean Association For Science Education
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• v.40 no.2
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• pp.141-150
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• 2020

The purpose of this study is to critically review the skill-based approach to scientific inquiry in science education and to explore the meaning of science practices that are emphasized in recent science education reform movement. An extensive review of relevant literature was carried out, and the results were summarized according to the detailed themes of the study. In the skill-based approach of which Science-A Process Approach (SAPA) is a representative example, science process skills were presented as hierarchically connected with one another, they were believed to be transferable or generalizable, and science learning through discovery was stressed. These points of view are, however, contradicted with those of the modern philosophy of science which suggests the theory-laden nature of using the skills. The skill-based view has also been criticized by the fact that the use of inquiry skills is content-specific or context-dependent and that science theories or principles cannot be discovered by induction. In contrast, the recent view understands science practices holistically, emphasizes the diverse ways of doing the practices which vary with different contents or contexts, and considers student ideas importantly in the science classroom. The findings of this study can contribute to the development of a new science curriculum by providing implications for establishing a consistent view on scientific inquiry.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.149-154
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• 2010

The objective of this study was to investigate the effects of abnormal ovarian cycles after superovulation treatment of Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg $PGF_2{\alpha}$ was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received $100\;{\mu}g$ GnRH at the time of Ind insemination. Embryos were recovered 7 or 8 days after the 1st insemination. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. 50.0 percentage of the cows (18/36) had normal resumption of ovarian cyclicity (resumption within 40 days after superovulation), and 50.0% (18/36) had delayed resumption(resumption did not occur until>40 days after superovulation). Delayed resumption Type II (first ovulation did not occur until $\geq$ 40 days after superovulation, i.e. delayed first ovulation 33.3%) were the most common types of delayed resumptions. The mean numbers of total ova from < 10 and 10$\leq$ of corpora lutea (CL) was 7.3 and 13.9, respectively. The number of transferable embryos differed between < 10 and 10$\leq$ CL was 4.2 and 5.1, respectively. 11.1 percentage of the cows (4/36) did not resumption their ovarian cyclicity until 60 days after superovulation treatment.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.141-144
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• 2010

In vivo embryo produced from Hanwoo donor cows were collected and transferred to Hanwoo recipients. Cows, at random stages of the estrous cycle, received Progesterone Releasing Intravaginal Device (CIDR-plus, InterAg, New Zealand) together with injection of 1 mg estradiol benzoate and 50 mg progesterone, and gonadotropin treatment began 4 day later. For superovulation, a total of 28 mg FSH was intramuscularly injected twice a day in the way of decreasing doses 4 day (5, 5, 4, 4, 3, 3, 2 and 2 mg). Twenty one Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered 7 days after the second insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: The rates of transferable embryos were 50.3%, and 78 fresh embryos at morulae and blastocysts stage were transferred into Hanwoo recipients on day 7 of estrus cycle. The pregnancy rates were first embryo transfer 55.6%, 2nd 62.9% and 3rd 57.9%, respectively. In conclusion, These results suggest that CIDR-based superovulation protocol may be effectively used for production of superior Hanwoo embryos. Also, since it seems the condition of recipient cows greatly affect pregnancy rate, it is very important to evaluate recipient for effective cattle production.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.201-205
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• 2010

The objective of this study was investigate the superovulation treatment and to relate concentrations of blood urea nitrogen(BUN) in Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg $PGF_2a$ was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received $100\;{\mu}g$ GnRH at the time of 1st insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN <10, 11~18 and ${\geq}$19 mg/dl had return of estrus of 34.6, 30.5 and 30.4 days respectively. Return of estrus after superovulation treatment was not significantly lower for cows with blood urea nitrogen (BUN) above 10 mg/dl than for cows with BUN below 10 mg/dl. Cows with BUN <10, 11~18 and ${\geq}$19 mg/dl had number of transferable embryos of $3.2{\pm}1.2$, $5.4{\pm}1.9$ and $4.1{\pm}2.1$ respectively.

• Journal of Embryo Transfer
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• v.17 no.1
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• pp.1-5
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• 2002

The purpose of this study was carried out to determine the possibility of continued embryo collection by repeatable superovulation from a Hanwoo elite cow, who was already estimated to an elite cow by DNA analysis. The donor cow was superovulated with Folltropin-V and PG $F_2$$\alpha$ combination method for 5 times, 2 months interval during 10 months. The estrus cows were inseminated with frozen semen 3 times 12 hrs interval. Embryo collection from superovulated cows was flushed non-surgical method at 7 to 8 days after artificial insemination. The superovulated cow was collected from 1 to 5$^{th}$ times as total (14, 4, 10, 6, 9 embryos; total 30 embryos) and transferable embryos (7, 4, 10, 3, 6; Mean$\pm$S.E : 6.0$\pm$2.7 embryos). Seventeen recipients were transferred 24 embryos and then detected to pregnant 10 recipients after embryo transfer (58.8%; 10/17 recipients) The results indicated that the possibility of repeatable superovulation from elite donor cow for embryo transfer could be confirmed in this study, although the replicated number was not enough.

• Journal of fish pathology
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• v.5 no.1
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• pp.37-48
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• 1992

Antibiotics are chemical substances produced by various species of microorganisms that suppress the growth of other microorganisms or may destroy them. Among the more than 4000 antibiotics that has been identified, about 20s are using as the therapy of infectious fish diseases. There are several methods used to classify and group antibiotics, and the most common classification has been based on chemical structure and proposed mechanism of action. The effect of antibiotics may be determined by the kind of fish pathogens and by the external environment surrounded the infected fish. It implies that the kind of antibiotics and its application method should be decided after the determination of the reasons of fish disease. The uncontrolled usages of antibiotics may induce the selection of resistant mutants appeared spontaneously and present in any group of bacteria. The epidemic spread of such antibiotic resistant strains of fish pathogenic bacteria already has been reported in various districts of japan. Importantly, transferable drug resistant(R) plasmids were detected in strains of most of fish pathogens. Based on those reports, the antimicrobial resistance appears to be a rapidly emerging problem in the fish industry on the country. The expanding literatures on the pharmacokinetics, clinical trials, withdrawal periods and efficacy of environmental effect for the commonly using antibiotics have met the needs of data for the practical application of antibiotics. However, the most important thing for the treatment of fish diseases would be the communication and exchanging of information between the site of aquaculture and the diagnostic laboratory.