• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.702-707
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• 1999

A percoll density gradient technique was developed for producing high quality turkey semen and improving the fertility by removing deleterious cellular components, including spermiophages, bacteria, abnormal or dead spermatozoa, and other cellular debris. The combination of three different percoll densities, 1.05, 1.07, and 1.08 showed the best resolution and was selected to prepare a discontinuous percoll density gradient to obtain healthy spermatozoa from semen smples. Bacteria, spermiophages, and abnormal or dead spermatozoa were detected from the density range from 1.05, 1.05 to 1.07, and 1.07 to 1.08, respectively. Healthy spermatozoa were collected from the density greater than 1.08. Spermatozoa obtained from percoll density gradient centrifugation showed better sperm motility than those from unprocessed pooled semen. Bacteria including Escherichia coli, Staphylococcus aureus, and Proteus spp., were predominant contaminants in turkey semen, and the numbers of cells were approximately $5{\times}10^5$ to $1{\times}10^9cfu/ml$. The overall fertility rates in hens inseminated with processed percoll density gradient were higher than those in hens with unprocessed semen especially for unhealthy sperm. In conclusion, semen quality can be improved by percoll density gradient centrifugation, which augmented the fertility of turkey breeders.

• Journal of Embryo Transfer
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• v.26 no.1
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• pp.9-12
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• 2011

This study was undertaken to determine whether the presence of fertility-associated antigen (FAA) in semen would influence semen characteristics and conception rate of artificial insemination in Hanwoo. The response to FAA of 36 heads of proven bull, 7 heads of young bull, and 27 heads of performance-tested bull was that one proven bull was FAA-negative and the others were FAA-positive, therefore FAA-negative bull was 1.4%. FAA-negative bull was lower in first and second semen concentrations than those of FAA-positive bull in 5,301 semen of 21 heads of proven bull, then FAA-negative bull was fewer as 11.5% in total sperm counts. The estrus of 22 heads was 70d-nonreturned in 36 cows first inseminated with frozen semen of FAA-negative bull, but that of 249 heads in 378 cows first inseminated with frozen semen of FAA-positive bull. Each conception rate was 61.1% and 65.9%, respectively. The difference of conception rates was 4.8%. These results indicate that the response of FAA to semen were influenced semen characteristics and conception rate of artificial insemination, but further investigations are needed to confirm the results.

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.79-90
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• 1999

This study was conducted to provide basic understandings for proper management of zoysiagrass fairways. Mowing intervals of 2, 4 and 6-days, with and without aeration were compared at two fertility levels. Turfgrass quality, growth and pest infestation were evaluated. Turf density, number of tillers, leaf width and resiliency were significantly affected by mowing frequency. Turfgrass plots mowed every 2-day had greater density, tillering, and resiliency but had narrower leaf width compared to other mowing treatments. Clipping dry weight with every 2-day mowing increased in the early stage of mowing treatment regardless of fertilizer application rates but gradually decreased in the later stage of mowing treatment compared to every 4 or 6-day mowings. The dry weight of above-ground part was not affected by mowing frequency, but that of underground part was significantly higher for every 6-day mowing frequency(3.3kg/day/m2) compared to every 2 or 4-day mowings. The organic mater content in soil was not different among mowing treatments but it was significantly reduced by the core aerification treatment, indicating significant effect of core aerification on thatch decomposition. Occurrences of weeds such as annual bluegrass and crabgrass according to mowing frequency were greater in every 2-day mowing treatment, while plots mowed every 6 days had less weed occurrence. Occurrence of rusts significantly increased in high fertility plots and frequently mowed turfgrasses.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.93-98
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• 2021

To develop policies regarding fertility and pregnancy that will be effective in preventing further declines in fertility rates in the context present-day Korea, current policies in Japan were analyzed and compared with those now being implemented in Korea. This study was structured to involve (a) comparison of maternal health projects in Korea and Japan, and (b) comparison of infertility support policies based in regional cities in Korea and Japan. Korea's Health Plan 2030 emphasizes strengthening healthcare for high-risk pregnant women, expanding investments to benefit vulnerable groups, and establishing a support system for infertile couples. In Japan, government programs involving treatment targeting infertility specifically were implemented nationwide in 2006. Wide dissemination of accurate knowledge related to pregnancy is emphasized. Also, counseling centers specializing in infertility were established by 67 local governments. We have confirmed that Korean policies include decentralization, while Japan is implementing the central government's infertility policy uniformly in all regions. Japan also adjusted its policy out of concern that problems related to infertility and childbirth will worsen due to the social disaster of COVID-19. The results indicate that providing additional support for psychological counseling may be preferable to increasing the number of in-vitro fertilization procedures. The physical burden on women may be minimized by benchmarking policies in Japan. Step-by-step application of these procedures should be systematically supported to achieve the best results.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.1
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• pp.55-64
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• 2005

Objective: Human infertility clinics have been faced the demand for improving clinical results. The purpose of this study was to evaluate the effect of microsurgical removal of damaged blastomeres (DB) in frozen-thawed embryos on the clinical outcomes. Methods: From January 2003 to May 2004, out of 258 thawing ET cycles were divided into three groups: Group-1 (n=46): Intact cleavaged embryos after thawing. Remained cycles with embryos containing DB were randomly divided into two groups. Group-2 (n=102): Drilling zona pellucida (ZP) of frozen-thawed embryos by acidified Tyrode's solution. Group-3 (n=110): Drilling ZP and removal of DB. Embryos after microsurgical manipulation were transferred into the uterus of patients. Results: Clinical profiles and the mean number of transferred embryos among three groups were not different. Pregnancy and implantation rates were similar in three groups. It were 30.4% and 9.3% in Group-1, 29.4% and 7.8% in Group-2, and 26.4% and 7.6% in group-3, respectively. Miscarriage rate in Group-3 (37.9%) was slightly higher than those in Group-1 and Group-2 (14.3% and 23.3%), but it was not statistically significant. Conclusion: Intact cleaving embryos after DB removal showed higher potent of pregnancy and implantation. We could not find any improvement of clinical outcome by removal of DB in frozen-thawed embryos.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.2
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• pp.90-95
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• 2017

Objective: We investigated whether the insemination method (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]) affected morphokinetic events and abnormal cleavage events in embryonic development. Methods: A total of 1,830 normal fertilized embryos were obtained from 272 IVF and ICSI cycles that underwent ovum retrieval culture using a time-lapse system (Embryoscope) from June 2013 to March 2015. All embryos were investigated by a detailed time-lapse analysis that measured the developmental events in the hours after IVF or ICSI insemination. Results: No significant differences were observed between the two groups regarding clinical outcomes (p>0.05). ICSI-derived embryos showed significantly faster morphokinetics than those derived from conventional IVF, from the time to pronuclear fading to the time to 6 cells (p<0.05). However, no significant differences were found from the time to 7 cells to the time to expanded blastocyst (p>0.05). There were no differences in abnormal cleavage events between the two groups (p>0.05); they showed the same rates of direct cleavage from 1 to 3 cells, 2 multinucleated cells, 2 uneven cells, and reverse cleavage. Conclusion: The morphokinetics of embryo development was found to vary between IVF- and ICSI-fertilized oocytes, at least until the 6-cell stage. However, these differences did not affect the clinical outcomes of the embryo. Additionally, no significant differences in abnormal cleavage events were found according to the fertilization method.

• The Korean Journal of Applied Statistics
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• v.33 no.4
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• pp.421-437
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• 2020

This paper implemented a method to predict the fertility rate, mortality rate, and international migration rate using the R program, which has been widely used in recent years, that calculates population projection by substituting the results into the Leslie matrix. In particular, the generalization log gamma model for the fertility rate by Kaneko (2003), LC-ER model for mortality rate by Li et al. (2013), and functional data model for international migration rates proposed by Ramsay and Silverman (2005) and Hyndman and Booth (2008), Hyndman et al. (2013) can be directly demonstrated with R programs. Demography and bayesPop have been introduced as a representative demographic package implemented in R; however, it can be analyzed only for data uploaded to Human Mortality Database (HMD) and Human Fertility Database (HFD) with data changes and modifications requiring application of other data. In particular, in Korea, there is a limitation in applying this package because it is provided only for short-term data in HMD. This paper introduces an R program that can reflect this situation and the different patterns of low fertility, aging, migration of domestic and foreigners in Korea, and derives a population projection for the year 2117.

• Asian Journal of Turfgrass Science
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• v.18 no.2
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• pp.71-76
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• 2004

Solid typed organic fertilizer from cattle manure may Increase plant root growth with the residual effect on soil fertility if it was applied directly into root system. It may also increase labour efficiency by simplifying the work process of manure application to soil. This research was carried out from May to October 1999 to study the fertility prolongation effects of bar typed organic fertilizer from poultry manure by analysing plant growth model compare with those of the chemical fertilizer or powder typed manure. The results showed that the bar typed organic fertilizer increased growth rates of shoot and root system with extending the effect of its fertility by slow releasing on pepper plant. Especially, solidifying organic manure into the bar type made possible the application of cattle manure under plastic mulching. And it also has benefits on simplifying the application process of the fertilization and effect on an extending soil fertility.

• Development and Reproduction
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• v.13 no.3
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• pp.145-153
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• 2009

Previously, we obtained the list of genes differentially expressed between GV and MII oocytes. Out of the list, we focused on functional analysis of Zap70 in the present study, because it has been known to be expressed only in immune cells. This is the first report about the expression and its function of Zap70 in the oocytes. Synthetic 475 bp Zap70 dsRNA was microinjected into the GV oocytes, and the oocytes were cultured in vitro. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression levels of transcripts of three kinases, Erk1/2, JNK, and p38, were determined. Zap70 is highly expressed in immature GV oocytes, and gradually decreased as oocyte matured. When dsRNA of Zap70 was injected into the GV oocytes, Zap70 mRNA specifically and completely decreased by 2 hr and its protein expression also decreased significantly. Absence of Zap70 resulted in maturation inhibition at meiosis I (57%) with abnormalities in meiotic spindle formation and chromosome rearrangement. Concurrently, mRNA expression of Erk2, JNK, and p38, were affected by Zap70 RNAi. Therefore, we concluded that Zap70 is involved in MI-MII transition by affecting expression of MAP kinases.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.1
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• pp.53-60
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• 2011

Objective: This study was carried out to compare the clinical outcome of elective single cleavage-embryo transfer (eSCET) to that of elective single blastocyst-embryo transfer (eSBET) in human IVF-ET. Methods: This study was a retrospective study which analyzed for 614 women who visited the Daegu Maria Clinic from August 2008 to December 2009. All were under 37 years old and had more than 8 mm of endometrial thickness on the day of hCG administration and at least one good quality embryo on day 3. The eSCETs were performed on day 3 (n=450) and the eSBETs were conducted on day 5 (n=164). Results: The numbers of retrieved oocytes, fertilized oocytes, and day 3 good quality embryos were significantly lower in the eSCET group (12.1${\pm}$6.0, 8.2${\pm}$4.6, and 4.2${\pm}$3.1, respectively) compared to the eSBET group (16.7${\pm}$7.2, 12.1${\pm}$5.0, and 8.5${\pm}$4.5, respectively; p<0.001). However, the clinical pregnancy, implantation, on-going pregnancy, and live birth rates of the eSCET group (46.7, 46.9, 40.0, and 36.7%, respectively) were not statistically different from those of the eSBET group (51.2, 51.8, 45.1, and 43.9%, respectively; p=0.318, 0.278, 0.254, and 0.103, respectively). Conclusion: These results suggested that elective single embryo transfer should be performed regardless of the developmental stage to women less than 37 years old who had more than 8 mm of endometrial thickness on the hCG administration day and at least one good quality embryo on day 3 in order to reduce the twin pregnancy rate without reducing the whole pregnancy rate.