• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.21-38
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• 1992

The present study was carried out to investigate morphologic changes in the corpus luteum of the pregnant rat by electron microscope after administration of prostaglandin F2$\alpha$(PGF2$\alpha$). Pregnant rates were treated with PGF2$\alpha$(1,500$\mu\textrm{g}$/rat) and their corpura lutea were observed morphologically. The results obtained in this study were summarized as follows ; 1. The weight of the ovaries and corpura lutea were decreased slightly at 8~24 hours after PGF2$\alpha$ administratin but no significant differences were observed. 2. The number of corpora lutea and luteal cells decreased slightly at 12~48 hours and 18~24 hours after PGF2$\alpha$ tretment but there were no signifciant differences between control and treatment. 3. The weight of uterus and the unmber of embryo decreased slightly at 96 hours and at 18~96 hours after PGF2$\alpha$ administration but no significant differences were obtained. 4. In the electron microscopic observatons, lipid droplets which are electron dense and appear in the cytoplasm moderately increased in number after PGF2$\alpha$ treatment. The lipid droplets were surrounded by mitochodria and appeared in the autophagic vacuoles. 5. Moderated and high electron dense mitochondria which are round or elongated in shape showed pleomorphism from 3 hours after PGF2$\alpha$ treatment. Destruction of tubular of vesicular cristae was observed at 6 hours after the treatment. Dense body and myelin figures in matrix of mitochondria were also appeared. 6. Well-developed smooth endoplasmic reticulum(sER) showed tubular or vesicular cisternae. A number of whorl membranes containing ribosomes, mitochondria and lipid droplets were observed at 1.5 hour after treatment. sER was abundant in luteal cells at 12 hours were treatment. 7. Well-developed Golgi pparatus appeared obviously 6 hours and more prominently at 12 hours. Those Golgi vesicles were remarkably dilated. 8. Generally, a few rough endoplasmic reticulum (rER) were appeared after treatment and cisternae showed slight dilatation. No differences among the treatments were observed. However, slight dilation of cisternae was observed at 1.5 hours after treatment. 9. Ribosomes composed of free and polyribosomes were abundant before treatment but polyribosomes were appeared at 12 to 24 hours after treatment. 10. Intercellular space were slightly extended at 3 hours and markedly extended at 12 hours. Numerous microvillous protrusions were observed at these times. Membranous multivesicular structures and autophagic vacuoles were also appeared in the intercellular space. 11. At 3 hours after the treatment, autophagic vacuoles appeared in the cytoplasm of the cell. They increased in number with time and were observed to transfer to the intercellular space. Lysosomal dense body appeared in the cytoplasm and the inclusion body was also observed in nucleus at 12 to 24 hours after treatment.

• Korean Journal of Animal Reproduction
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• v.19 no.2
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• pp.147-152
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• 1995

The purpose of this study was to examine the estrus synchronization and superovulation of pigs with hormone treatments. Three different kinds of procedures for synchronization and superovulation were used as follow: I) gilts in natural estrus behavior (control): 2) gilts synchronized with 20mg altrenogest for 9 days regardless of the estrus cycle; 3) gilts received PG600 (400IU PMSG + 200 IU hCG) in 15 day of the estrus cycle; and then gilts administrated with PMSG (1,500 IU) and hCG (750 IU) after altrenogest and PG600 treatment for superovulation. Estrus was checked daily with a boar, in estrus synchronization, the intervals from hormone treatment to estrus were different between PG600 (43/47) and altrenogest (13/53) within 6 days. The percentage of animals displaying a estrus response were not different by hormone treatments. The average number of corpora lutea (C.L) and ovulated embryos were similar between PG600 25.4${\pm}$13.1, 19.0$\pm$12.8 and altrenogest 25.5${\pm}$0.7, 15.0${\pm}$4.2, respectively, but was increased (P<0.05) by hormone treatment compared to that 12.9${\pm}$1.8, 12.7${\pm}$3.9 in the control. The number of normal embryos after ovulation was higher in the control than hormone treatment. Therefore, these results suggest that altrenogest and PG600 treatment could be a valuable for cut down the labour and cost by synchronization.

• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.307-322
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• 1996

The corpus luteum (CL) is formed by the action of a surge of luteinizing hormone (LH) on the pre-ovulatory follicle. Luteal cells derived from granulosa and theca interna cells continue to secrete progesterone for about two weeks. LH in domestic animals is essential for the normal secretion of progesterone at all stages of the luteal phase. For this process in the rodents, 20$\alpha$-hydroxysteroid dehydrogenase (20$\alpha$-HSD) is indispensable. 20$\alpha$-HSD is an enzyme to be a biologically inactive steroid. This enzyme plays a critical role in the regulation of the rat luteal function and reported to be present in steroid-producing tissues such as the testis and adrenal gland. We have purified 20$\alpha$-HSD and found two distinct 20$\alpha$-HSD molecules (HSD-1 and HSD-2). Their molecular weights are both estimated to be 33kd.The amino acid compositions of HSD-1 and HSD-2 are mostly similar, but there is a slight difference in the content of lysine. We demonstrated that 1) CL of previous generations contribute more to whole ovarian 20$\alpha$-HSD activity, 2) newly formed corpora lutea contain only 20$\alpha$-HSD-1 activity, and 3) old CL express activities of each HSD isozyme as shown in the luteal tissue of cycling rats on the day of diestrus where only degenerating old CL exist. The increase in 20$\alpha$-HSD activity identified seems to be related to the increase in the numbers of 20$\alpha$-HSD-positive cells. Interestingly, 20$\alpha$-HSD-1 activities were strongly found in the follicle fluids and theca interna cells by immunohistochemical study. Thus, the activity of 20$\alpha$-HSD may be related to a survival mechanism of those luteal cells and follicles remaining in the ovaries. Luteal cells arise from two sources. The small luteal cells are all of theca cell origin, while the large luteal cells are mainly of granulosa cell origin. CL of Korean Native Cattle, as those of other animal species, contains two morphologycally and functionally distinct luteal cell populations, such as small and large luteal cells as well as nonluteal cells. In all reproductive states except in the late luteal phase, the bovine CL also contained more small luteal cells than large luteal cells. Luteal tissue secretes a variety of growth factors (proteins) and the pattern of secretion changes during all stages of the luteal phase. These growth factors could be important in regulating the function of the bovine corpus luteum and may act in a potential endocrine autocrine and paracrine mechanisms. Therefore, further work has to be done to elucidate the role of growth factors in the ovary, especially in the corpus luterum. Interest should be focussed on interaction of these growth factors in the regulation of luteal cell and the localization of cytokine synthesis in differnet luteal cells.

• 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.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.373-381
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• 1989

The aim of the present study was to test the efficiency of estrous induction in the premature, metestrous and anestrous bitches. The estrus was induced with prostaglandin $F_{2{\alpha}}$, estradiol-$17{\beta}$, pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin(HCG) in the treatment A, and with PMSG and HCG in the treatment B. Day 0 was the first day of estrone injection in the treatment A and the day of PMSG injection in the treatment B. Twenty three of the twenty six bitches were laparotomized under general anesthesia between 11 and 18 days after onset of behavioral estrus, whereas three bitches were not laparotomized and remained until parturition. Ovarian responses were evaluated with the total number of corpora lutea or ovulation sites. The uterine horns were flushed with phosphate-buffered saline added heat treated canine serum(10%), the flushing media was collected into watch glass and the ova were examined under stereomicroscope. The results obtained were as follows: 1. Standing estrus was observed on the day $17.7{\pm}1.5$ after injection of estrone in the treament A, but ovarian responses were not detectable. 2. Standing estrus was observed on the day $12.2{\pm}0.2$ after injection of PMSG in the treament Band 14 of 17 bitches showed ovarian responses. Ova were recovered in 9 of the 14 bitches. 3. Ovarian responses were observed in one of the three premature bitches. two of the three metestrous bitches and all of the 11 anestrous bitches. The average number of the ova collected from 9 bitchs were $12.2{\pm}1.4$. 4. Three bitches in the treament B exhibited behavioural estrus and all of them were mated with fertile male dog, resulting the pregnancy in only one bitch. The pregnant bitch gave the birth of two pups.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3874-3884
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• 2000

An information retrieval system has to retrieve all and only documents which are relevant to a user query, even if index terms and query terms are not matched exactly. However, term mismatches between index terms and qucry terms have been a serious obstacle to the enhancement of retrieval performance. In this paper, we discuss automatic term normalization between words in text corpora and their application to a Korean information retrieval system. We perform two types of term normalizations to alleviate semantic term mismatches: equivalence class and co-occurrence cluster. First, transliterations, spelling errors, and synonyms are normalized into equivalence classes bv using contextual similarity. Second, context-based terms are normalized by using a combination of mutual information and word context to establish word similarities. Next, unsupervised clustering is done by using K-means algorithm and co-occurrence clusters are identified. In this paper, these normalized term products are used in the query expansion to alleviate semantic tem1 mismatches. In other words, we utilize two kinds of tcrm normalizations, equivalence class and co-occurrence cluster, to expand user's queries with new tcrms, in an attempt to make user's queries more comprehensive (adding transliterations) or more specific (adding spc'Cializationsl. For query expansion, we employ two complementary methods: term suggestion and term relevance feedback. The experimental results show that our proposed system can alleviatl' semantic term mismatches and can also provide the appropriate similarity measurements. As a result, we know that our system can improve the rctrieval efficiency of the information retrieval system.

• Reproductive and Developmental Biology
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• v.36 no.3
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• pp.231-235
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• 2012

The objective of this study was to investigate the comparison of transferable embryos and pregnancy rate between Hanwoo and Chickso. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on Hanwoo 78%, and Chickso 85%, respectively. The mean number of total embryos are each $14.76{\pm}2.16$ and $6.23{\pm}1.07$. So the mean number of transferable embryos are each $10.94{\pm}1.91$ and $4.58{\pm}1.05$. In addition, the mean number of total Hanwoo embryo from <10 and $10{\leq}$ of corpora luteum was $0.50{\pm}0.50$, $11.56{\pm}1.92$, respectively. In case of Chickso, The mean number of transferable embryo from <10 and $10{\leq}$ of CL was $2.75{\pm}1.39$, $6.00{\pm}1.00$, respectively. The pregnancy rates were Hanwoo 40%, and Chickso 37% following transfer of fresh embryos produced in vivo. Also, the pregnancy rates of Chickso 60% were significantly greater (p<0.05) than the Hanwoo 42.48% following transfer of following transfer of frozen embryos, respectively. In conclusion, these results suggest that Chickso may be effectively used for transferable embryos production in Hanwoo. Although the transferable embryos number was not enough, it seems the Chickso greatly affect pregnancy rate. The results indicated that the possibility of transferable embryos from Chickso for embryo transfer could be confirmed in this study. Based on the present findings, it was suggested that it is very important to evaluate in vivo embryo production and pregnancy rate of embryo transfer following superovulation for effective Hanwoo and Chickso production.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.335-339
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• 2011

The objective of this study was to investigate the relationship between concentration of urea nitrogen, glucose, cholesterol and number of transferable embryos for the purpose of improving reproductive performance in blood of Hanwoo donors. Fifty five, 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 1nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN < 10, 11~18 and ${\geq}$19 mg/dl had number of transferable embryos of $4.32{\pm}1.3$, $5.8{\pm}1.8$ and $4.7{\pm}2.1$ respectively. The mean numbers of total ova from < 10 and 10${\leq}$ of corpora lutea(CL) was 8.9 and 14.3, respectively. The number of transferable embryos differed between < 10${\leq}$ CL was 4.8 and 5.6, respectively.

• Reproductive and Developmental Biology
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• v.37 no.1
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• pp.35-40
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• 2013

The objective of this study was to investigate the effects of abnormal ovarian cycles after superovulation treatment of Holstein Donor Cows. CIDRs were inserted into the vaginas of twenty two head of Holstein cows, regardless of estrous cycle. Superovulation was induced using folliclar stimulating hormone (FSH). For artificial insemination, donor cows were injected with $PGF_2{\alpha}$ and estrus was checked about 48 hours after the injection. Then they were treated with 4 straws of semen 3 times, with 12-hour intervals. Embryos were collected by a non-surgical method 7 days after the first artificial insemination. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. Seventy two point seven percentage of the cows(16/22) had normal resumption of ovarian cyclicity(resumption within 40 days after superovulation), and 27.3%(6/22) 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 13.6%) were the most common types of delayed resumptions. The mean numbers of total ova from < 10 and $10{\leq}$ of corpora lutea(CL) was $7.8{\pm}1.8$ and $12.7{\pm}2.7$, respectively. The number of transferable embryos differed between < 10 and $10{\leq}$ CL was $5.4{\pm}1.3$ and $8.1{\pm}3.4$, respectively. Four point five percentage of the cows(1/22) did not resumption their ovarian cyclicity until 60 days after superovulation treatment. Diverse researches on the superovulation treatment method that is suitable for high-producing Holstein donor cows would contribute to preventing ovarian cyclicity disorder, as well as to the early multiplication of cows with superior genes by increasing the utilization value of donor cows.

• Korean Journal of Cognitive Science
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• v.22 no.1
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• pp.57-78
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• 2011

Paraphrasing is the act of writing a text using other words without altering the meaning. Paraphrases can be used in many fields of natural language processing. In particular, paraphrases can be incorporated in machine translation in order to improve the coverage and the quality of translation. Recently, the approaches on paraphrase extraction utilize bilingual parallel corpora, which consist of aligned sentence pairs. In these approaches, paraphrases are identified, from the word alignment result, by pivot phrases which are the phrases in one language to which two or more phrases are connected in the other language. However, the word alignment is itself a very difficult task, so there can be many alignment errors. Moreover, the alignment errors can lead to the problem of selecting incorrect pivot phrases. In this study, we propose a method in paraphrase extraction that discriminates good pivot phrases from bad pivot phrases. Each pivot phrase is weighted according to its reliability, which is scored by considering the lexical and part-of-speech information. The experimental result shows that the proposed method achieves higher precision and recall of the paraphrase extraction than the baseline. Also, we show that the extracted paraphrases can increase the coverage of the Korean-English machine translation.