• 한국동물생명공학회지
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• 제36권2호
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• pp.91-98
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• 2021

The objective of this study was to establish a selection process for high quality sperm in bovine semen using sperm separation by magnetic activation (MACS). For this, semen from 21 Nellore bulls was collected using an artificial vagina. To guarantee the presence of pathologies in the ejaculate, animals previously declassified in four consecutive spermiogram were used. Semen was analyzed in five statuses: (1) fresh semen (fresh); (2) density gradient centrifugation (DGC), percoll column; (3) non-apoptotic fraction after separation by MACS (MAC); (4) apoptotic fraction from the separation (MACPOOR); and (5) MAC followed by DGC (MACDGC). Using a computerized analysis system (CASA), motility was measured. The sperm morphology was evaluated by phase contrast, and the supravital test was completed with eosin/nigrosin staining. For DGC, 20 × 10⁶ cells were used in a gradient of 90% and 45% percoll. MACS used 10 × 10⁶ cells with 20 μL of nanoparticles attached to annexin V, and filtered through the MiniMACS magnetic separation column. Membrane integrity was assessed with SYBR-14/IP and mitochondrial potential with JC-1 by flow cytometry. Processing sperm by MACDGC, was more effective in obtaining samples with high quality sperm, verified by the total of abnormalities in the samples: 35.04 ± 2.29%, 21.50 ± 1.47%, 17.30 ± 1.10%, 30.68 ± 1.94% and 10.50 ± 1.46%, respectively for fresh, DGC, MAC, MACPOOR, and MACDGC. The subpopulation of non-apoptotic sperm had a high number of live cells (82.65%), membrane integrity (56.60%) and mitochondrial potential (83.98%) (p < 0.05). These findings suggest that this nanotechnological method, that uses nanoparticles, is efficient in the production of high-quality semen samples for assisted reproduction procedures in cattle.

• Animal Bioscience
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• 제35권9호
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• pp.1340-1350
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• 2022

Objective: Luxi Black Head sheep (LBH) is the first crossbreed specialized for meat production and was developed by crossbreeding Black Head Dorper sheep (DP) and Small Tailed Han sheep (STH) in the farming areas of northern China. Research on the genomic variations and selection signatures of LBH caused by continuous artificial selection is of great significance for identifying the genetic mechanisms of important traits of sheep and for the continuous breeding of LBH. Methods: We explored the genetic relationships of LBH, DP, and several Mongolian sheep breeds by constructing phylogenetic tree, principal component analysis and linkage disequilibrium analysis. In addition, we analysed 29 whole genomes of sheep. The genome-wide selection signatures have been scanned with four methods: heterozygosity (H_P), fixation index (F_ST), cross-population extended haplotype homozygosity (XP-EHH) and the nucleotide diversity (𝜃_π) ratio. Results: The genetic relationships analysis showed that LBH appeared to be an independent cluster closer to DP. The candidate signatures of positive selection in sheep genome revealed candidate genes for developmental process (HoxA gene cluster, BCL2L11, TSHR), immunity (CXCL6, CXCL1, SKAP2, PTK6, MST1R), growth (PDGFD, FGF18, SRF, SOCS2), and reproduction (BCAS3, TRIM24, ASTL, FNDC3A). Moreover, two signalling pathways closely related to reproduction, the thyroid hormone signalling pathway and the oxytocin signalling pathway, were detected. Conclusion: The selective sweep analysis of LBH genome revealed candidate genes and signalling pathways associated with developmental process, immunity, growth, and reproduction. Our findings provide a valuable resource for sheep breeding and insight into the mechanisms of artificial selection.

• Journal of Animal Science and Technology
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• 제56권4호
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• pp.15.1-15.10
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• 2014

Background: Morphologically classifying embryos is important for numerous laboratory techniques, which range from basic methods to methods for assisted reproduction. However, the standard method currently used for classification is subjective and depends on an embryologist's prior training. Thus, our work was aimed at developing software to classify morphological quality for blastocysts based on digital images. Methods: The developed methodology is suitable for the assistance of the embryologist on the task of analyzing blastocysts. The software uses artificial neural network techniques as a machine learning technique. These networks analyze both visual variables extracted from an image and biological features for an embryo. Results: After the training process the final accuracy of the system using this method was 95%. To aid the end-users in operating this system, we developed a graphical user interface that can be used to produce a quality assessment based on a previously trained artificial neural network. Conclusions: This process has a high potential for applicability because it can be adapted to additional species with greater economic appeal (human beings and cattle). Based on an objective assessment (without personal bias from the embryologist) and with high reproducibility between samples or different clinics and laboratories, this method will facilitate such classification in the future as an alternative practice for assessing embryo morphologies.

• 한국방사선학회논문지
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• 제18권3호
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• pp.267-273
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• 2024

본 연구에서는 코딩없이 인공지능 학습 모델을 개발할 수 있는 클라우드 기반의 버텍스 AI 플렛폼을 이용하여 비전문가인 일반인들이 손쉽게 인공지능 학습 모델을 개발하였고 임상적 적용가능성을 확인하였다. 학습용 데이터는 캐글 사이트에 공개된 총9개 치과 질환, 2,999장 치근병 X선 영상을 사용하였고, 무작위로 학습, 검증 및 테스트 데이터 이미지를 분류하였다. 버텍스 AI의 기본 학습모델 워크플로우에서 학습 파이프라인을 사용하여 하이퍼 파라미터 조정작업을 통해 영상분류, 멀티레이블 학습을 수행하였다. Auto ML을 수행한 결과 AUC가 0.967, 정밀도는 95.6%, 재현율은 95.2%로 나타났으며, 학습된 인공지능 모델이 임상적 진단에 충분한 의미가 있음을 확인하였다.

• 암석학회지
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• 제27권4호
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• pp.207-222
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• 2018

국립고궁박물관 소장 천상열차분야지도 각석 및 복각천상열차분야지도 각석은 우리나라의 전통 천문학 수준을 실증하는 대표적인 과학문화유산이다. 태조본 각석은 암갈색 점판암, 숙종본 각석은 회백색 백운암으로 서로 다른 암석으로 제작되었다. 태조본 점판암은 석영, 백운모, 백운석의 광물조성을 보였으며, 숙종본 백운암은 백운석, 고토감람석, 방해석으로 구성되어 있다. 태조본 각석은 숙종본에 비해 손상이 심화되어 있으며 주요한 손상인자는 균열 및 탈락이다. 숙종본에서는 긁힘과 인위적인 오염물이 관찰되었다. 태조본 및 숙종본 각석 측면과 후면에 나타나는 녹색 및 흑색 표면오염물은 수지 기반의 페인트 물질로 해석된다. 한편, 초음파 물성평가에서 태조본 각석은 좌측면 상부가, 숙종본 각석은 전면 우측부가 저속도대를 보인다. 태조본각석의 안정성을 저해하는 주요 균열에 대해 To-Tc법으로 발달 상태를 조사한 결과, 균열의 전개부 및 중심부에서 가장 깊은 심도가 측정되었다.

• 한국수산과학회지
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• 제31권5호
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• pp.713-720
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• 1998

유용 증양식 대상종으로 새끼를 낳는 볼락을 재료로하여 수온과 광주기 조절이 성숙과 번식주기에 미치는 효과를 파악하고, 출산시기의 제어 가능성을 검토하였다. 월별 GSI의 변화에서 암컷은 Exp.II와 III에서는 서로 큰 차이없이 11월부터 증가하기 시작하여 1월에 각각 13.0과 14.7로 최고값이 되었다. 수온과 광주기를 각각 2 개월씩 늦춘 Exp.I에서 조절에 반응하였던 어미들은 Exp.II와 III에 비해 1개월 늦어진 2월에 15.0으로 최고 값을 나타냈다. 그러나 Exp.I에서 조절에 반응하지 않았던 어미들은 전 실험기간 동안 0.5 이하로 낮게 유지되다. 수컷 GSI의 월별변화는 실험구에서 9월부터 증가하기 시작하여 Exp.I에서는 10월, Exp.II와 III에서는 11월에 각각 최고값을 보인후 급격히 감소하였으며, 실험구별로 차이를 나타내지 않았다. HSI의 월별 변화는 GSI와는 서로 상반된 경향을 나타냈으며, 수온과 광주기의 조절은 실험구별 어체의 GSI와 비만도의 변화에 영향을 미치지 않았다. 실험구별 생식소의 발달단계를 관찰한 결과, Exp.I에서 수온과 광주기 조절에 반응하였던 개체들의 난소는 Exp.II와 III에 비해 성숙과 출산이 지연되는 조직상을 나타냈으나, 정소에서는 실험구별 발달단계의 차이를 인정할 수 없었다. 수온과 광주기를 자연상태로 유지한 것과 이를 2개월 늦춘 실험구를 설정하여 사육한 결과, 암컷 볼락은 대조구 (Exp.II와 III)에 비해 조절구 (Exp.I-r)에서 성숙과 출산이 1$\~$2개월 지연된 반면, 수컷에서는 수온과 광주기의 조절 효과가 인정되지 알았다.

• 동물자원연구
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• 제29권4호
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• pp.158-165
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• 2018

본 연구는 Canada에서 수입한 동결정액으로 인공수정된 모돈의 번식성적을 조사하여 동결정액을 이용한 인공수정(동결정액 인공수정)의 효율을 개선할 수 있는 통찰력을 얻기 위해 수행되었다. 이를 위해 A(GGP) 농장에서 2016년 5월과 9월 사이 총 626회의 동결정액 인공수정과 B(GGP) 농장에서 2015년부터 2017년 기간 동안 수행한 총 2,429 동결정액 인공수정의 결과 기록을 분석하였다. A종 돈장에서 동결정액을 썼을 때 총산자수 및 실산자수는 9월 보다 5월에 높았다(p<0.05). B종돈장의 분만율, 총산자수 및 실산자수는 조사연도 간에 차이가 없었다. A종돈장 결과와 B종돈장 결과를 통합하여 분석했을 때, 분만율은 A종돈장이 높았으나(p<0.01) 총산자수와 실산자수는 두 종돈장간에 차이가 없었고, 동결정액 인공수정을 했을 때가 액상정액 인공수정을 했을 때보다 낮았다(동결정액:액상정액 인공수정에 대한 총산자수와 실산자수는 각각 $10.9{\pm}0.3:13.4{\pm}0.1$두 및 $10.0{\pm}0.3:12.0{\pm}0.1$두 이었음; p<0.01). 결론적으로, 이상의 결과는 동결정액 인공수정이 액상정액 인공수정보다 번식 효율이 낮긴 하지만 연중 적절한 시기에 동결정액 인공수정을 실시하면 번식 효율이 증가될 수도 있음을 시사한다.

• 한국환경과학회지
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• 제10권4호
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• pp.293-298
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• 2001

The toxicity values heavy metals were evaluated by immobilization and chronic reproduction impairment tests, using Daphnia magna. Acute tests were evaluated by the inhibition of their mobilization after 24hrs without food addition. The tests of reproductive impairment were investigated for 21 days by food addition and exchange or water. The effect of each concentration was assessed by Probit analysis and t-test. The results obtained from this study were as follows : 1) The change of pH and DO was not significant in the acute tests, while, in the reproductive tests, pH was increased by 0.3~1.4 and DO also increased. 2) The $E_iC_{50}$ values of immobilization to Daphnia magna in artificial fresh water were $0.030mg/{\ell}(Cu),\;0.054mg/{\ell}(Cd),\;0.12mg/{\ell};(Cr),\;0.74mg/{\ell}(Pb),\;3.4mg/ {\ell}(As)$ and the $NOE_iC$ values were $0.010mg/{\ell}(Cu),\;0.018mg/{\ell}(Cd),\;0.010mg/{\ell}(Cr),\;0.10mg/{\ell}(Pb),\;and\;$1.8mg/{\ell}(As)$. 3) The $E_rC_{50}$ values of reproductive impairment to Daphnia magna were $13.8\mu\textrm{g}/{\ell}(Cu),\;2.9\mu\textrm{g}/{\ell}(Cd),\;15.5\mu\textrm{g}/{\ell}(Cr),\;61.7\mu\textrm{g}/{\ell}(Pb),\;759\mu\textrm{g}/{\ell}(As)$, and $NOE_rC$ values were $0.95\mu\textrm{g}/{\ell}(Cu),\;$0.54\mu\textrm{g}/{\ell}(Cd),\;1.2\mu\textrm{g}/{\ell}(Cd),\;$7.4\mu\textrm{g}/{\ell}(Pb),\;110mu\textrm{g}/{\ell}(As)$. The results of tests using OECD artificial culture water were more sensitive than natural water for culturing. The presented data show that an artificial culture water is suitable in the experiment of bioassay for assessing the toxicity of marterials.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.227-232
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• 2011

This survey was conducted to investigate the current status of swine artificial insemination(AI) centers registered as 'semen processing business' in Korea. The survey responses were collected by direct visitation or telephone conversation for 5 months from May through September in 2008. The survey showed that sixty-four AI centers were enrolled in local government and those of fifty-two AI centers were under operation. Forty-nine AI centers surveyed owned a total of 3,334 boars and the Duroc breed accounted for the highest rate(73.1%) of all boar breeds. In type of ownership, agricultural management corporations was the highest(42.3%) and followed by private ownership(34.6%). Large-scale AI centers in terms of own over 151 boar were surveyed as 5.9% and most AI centers own less than 100 boars(86.5%). The average number of boars per AI center was 68. The amount of liquid semen provided by 52 AI centers were 1,791,000 doses and each AI center provides average of 39,000 does, which is represented for 90% consumption by sows in Korea.

• 한국발생생물학회지:발생과생식
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• 제21권1호
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• pp.101-110
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• 2017

On June 14, 2008 (the first experiment) and July 24, 2008 (the second experiment), the shores of the Boseong River and the sandy beaches, Seokgok-myun, Moksadong-myun, Gokseong-gun in Jeollanam Province were investigated and a total of 29 soft-shelled turtle (Tryonyx sinensis) eggs in the natural spawning nest eggs were collected (13 eggs were collected in the first experiment and 16 eggs in the second experiment). The temperatures in the natural spawning nests were $25.9-36.9{\pm}0.5^{\circ}C$, the depth of the eggs was $5.2-7.5{\pm}0.5cm$ as the distance of the average $6.4{\pm}0.5cm$. 29 eggs were scattered at least 0.2 cm interval. Artificial incubation of 29 eggs was conducted in artificial nest boxes in thermo-plastic composition of the incubator, and then incubated at $26.5-35.5{\pm}0.5^{\circ}C$, and an average constant temperature was $31.2-32.1{\pm}1.0^{\circ}C$. The incubation days ranged from 53 to 55. In case of most turtles, incubation at $31^{\circ}C$ (higher temperatures) generally produces all or mostly females, while incubation at $25^{\circ}C$(cooler temperatures) produces all or mostly males. Exceptionally, in case of genus Trionyx, the sex ratio of female : male of T. sinensis of a freshwater soft-shelled turtle was approximately 1:1, which differs from other genera of turtles and makes T. sinensis Strauch only turtles presently known to lack temperature-dependent sex determination.