• 한국해양바이오학회지
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• 제1권3호
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• pp.186-192
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• 2006

짧은 집단 반복 요소 (Short Interspersed Repetitive Elements, SINE) 는 수백개 정도의 염기로 구성된 반복염기서열로서 LINE (Long Interspersed Nucleotide Elements)와 함께 바이러스와는 구별되는 레트로트랜스포존 (Retrotransposon)의 하나로 알려져 있다. 이들의 생체 내 역할은 정확하게 밝혀진 것은 없지만 게놈 내에서 반복염기서열의 재배열을 통해 완전히 새로운 유전자를 창조하거나 기존의 유전자를 변형시킴으로써 유전물질의 운반수단 및 진화적 변화에 있어서 중요한 역할을 할 것이라 예상되며, 질병의 원인이 된다고도 밝혀져 있다. 본 연구에서는 미꾸라지로부터 SINE의 새로운 두 그룹을 분리하였다. 두 SINE 그룹, mlSINE-L과 mlSINE-S는 각각 약 410bp와 270bp의 염기로 구성되어 있다. 두 SINE 그룹의 5'과 3'말단의 서열은 RSg-1와 SmaI SINE 의 그것과 높은 유사도를 보였다. 계통발생분석결과, mlSINE들은 미꾸라지에서 유일하였으며, dot blot hybridization의 결과는 mlSINE-L이 미꾸라지 게놈 $2{\times}10^9bp$ (2.8 pg)당 $1{\times}10^3$ copy를 가지는 것으로 추정되며, loop DNA보다 핵기질부착부위 (nuclear matrix attachment regions, MARs)에서 그 분포도가 높았다. 이런 결과는 미꾸라지의 새로운 SINE 들이 핵기질 부착부위 내에서나 혹은 가까운 주변에 우선적으로 삽입될 수 있음을 나타낸다.

• Animal cells and systems
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• 제16권6호
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• pp.438-446
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• 2012

In 1964, Susumu Ohno, an evolutionary biologist, hypothesized that the size of X chromosome was conserved in mammalian evolution, and that this was based on chromosomal length. Today, unlike Ohno's method which was based on estimated lengths, we know the exact lengths of some mammalian sequences. The aim of this study was to reanalyze Ohno's hypothesis. In mammalian species, variation in the length of the X chromosome is greater than in the autosomes; however, this variation is not statistically significant. This means that differences in chromosomal length occur equally in the X chromosome and in the autosomes. Interspersed nuclear elements and genetic rearrangements were analyzed to maintain the same variance between the length of the X chromosome and the autosomes. The X chromosome contained fewer short interspersed elements (SINEs) (0.90 on average); however, it did contain more long interspersed elements (LINEs) than did autosomes (1.56 on average). An overall correlation of LINEs and SINEs with genetic rearrangements was observed; however, synteny breaks were more closely associated with LINEs in the autosomes, and with SINEs in the X chromosome. These results suggest that the chromosome-specific activities of LINEs and SINEs result in the same variance between the lengths of the X chromosome and the autosomes. This is based on the function of interspersed nuclear elements, such as LINEs, which can inactivate the X chromosome and the reliance of non-autonomous SINEs on LINEs for transposition.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.893-899
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• 2009

Few studies have reported the existence of imprinted genes in cattle compared to the human and mouse. Genomic imprinting is expressed in monoallelic form and it depends on a single parent-specific form of the allele. Comparative analysis of mammals other than the human is a valuable tool for explaining the genomic basis of imprinted genes. In this study, we investigated 34 common imprinted genes in the human and mouse as well as 35 known non-imprinted genes in the human. We found short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and long terminal repeats (LTRs) in imprinted (human and mouse) and control (cattle) genes. Pair-wise comparisons for the three species were conducted using SINEs, LINEs, and LTRs. We also calculated 95% confidence intervals of frequencies of repetitive sequences for the three species. As a result, most genes had a similar interval between species. We found 11 genes with conserved SINEs, LINEs, and LTRs in the human, mouse, and cattle. In conclusion, eleven genes (CALCR, Grb10, HTR2A, KCNK9, Kcnq1, MEST, OSBPL5, PPP1R9A, Sgce, SLC22A18, and UBE3A) were identified as candidate imprinted genes in cattle.

• 한국수학사학회지
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• 제36권2호
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• pp.21-34
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• 2023

Spherical trigonometry refers to the geometry related to spherical triangles. It has been an important tool for studying astronomy since ancient times. In trigonometry, concepts such as trigonometric functions naturally emerge from the relationship between arcs and chords of a circle. In this paper, we briefly examine the origin of spherical trigonometry. To introduce the basics of spherical trigonometry, we present fundamental and important theorems such as Menelaus's theorem, the law of sines and the law of cosines on a sphere, along with their proofs. Furthermore, we discuss the educational value and potential applications of spherical trigonometry.

• 대한수학교육학회지:수학교육학연구
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• 제15권2호
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• pp.131-145
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• 2005

이 논문은 중고등학교 학생들과 예비수학교사를 대상으로 삼각형의 결정조건과 합동조건에 대한 이해의 양상의 일단을 조사하고, 삼각형의 결정조건과 합동조건에 대해 교수학적으로 분석한 것이다. 연구 결과의 일부를 제시하면 다음과 같다. 첫째, 삼각형의 6요소 구하기 학습 지도시 중학교에서 배운 삼각형의 결정조건이 지닌 의미를 재음미할 기회를 제공해야 한다. 둘째, 무엇을 삼각형의 결정조건으로 볼 것인가는 결정조건을 탐구하는 맥락에 따라 달리 판단될 수 있는 문제이다. 셋째, 삼각형의 결정조건이 지닌 최소필수성을 인식할 수 있게 하는 교재 구성과 학습 지도가 필요하다. 넷째, 합동에서 '대응'의 중요성을 인식하게 하는 학습 지도가 필요하며, 삼각형의 합동조건에서 '대응하는' 이라는 표현이 지닌 문제점을 해소하는 방안을 모색할 필요가 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.891-895
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• 2019

Objective: Aim of present study was the set up of a fast and reliable protocol using species-specific markers for the quali-quantitative analysis of DNA and the detection of ruminant biological components in dairy products. For this purpose, the promoter of the gene coding for the ${\alpha}$-lactoalbumin (LALBA) was chosen as possible candidate for the presence of short interspersed nuclear elements (SINEs). Methods: DNA was isolated from somatic cells of 120 individual milk samples of cattle (30), Mediterranean river buffalo (30), goat (30), and sheep (30) and the gene promoter region (about 600/700 bp) of LALBA (from about 600 bp upstream of exon 1) has been sequenced. For the development of a single polymerase chain reaction (PCR) protocol that allows the simultaneous identification of DNA from the four species of ruminants, the following internal primers pair were used: 5'-CACTGATCTTAAAGCTCAGGTT-3' (forward) and 5'-TCAGA GTAGGCCACAGAAG-3' (reverse). Results: Sequencing results of LALBA gene promoter region confirmed the presence of SINEs as monomorphic "within" and variable in size "among" the selected species. Amplicon lengths were 582 bp in cattle, 592 bp in buffalo, 655 in goat and 729 bp in sheep. PCR specificity was demonstrated by the detection of trace amounts of species-specific DNA from mixed sources ($0.25ng/{\mu}L$). Conclusion: We developed a rapid PCR protocol for the quali-quantitative analysis of DNA and the traceability of dairy products using a species-specific marker with only one pair of primers. Our results validate the proposed technique as a suitable tool for a simple and inexpensive (economic) detection of animal origin components in foodstuffs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.414-417
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• 1999

According to development of power electric technology from industrial field to electronic home appliances, recent SMPS using semiconductor is spread widely. Electric converting instrument uses a sine wave voltage source, namely an usual power source, and it gets a non-sines power source from power source because current flows through one part in waveform of one cycle. This injects higher harmonic source in source part, absorb pollution source. And this cause quality deterioration, durability shortage of electric power instrument, spreading accident of electric solver system, and so on. It can't supply an electric source of good quality in industry, so become an impedimental element in improving productivity and reliance. This study can be used in prediction of hindrance and diagnosis material and intends to suggest a countermeasure about measurement data.

• 대한기계학회논문집
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• 제12권2호
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• pp.241-251
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• 1988

본 연구에서는 숫돌입자, 결합자 및 기공으로 조성된 연삭숫돌의 구조를 다공질 포성체로 보고, WA계 비트리파이드(vitrified) 및 레지노이드(resinoid) 결합자의 연삭숫돌시험편에 대하여 AE 계측방법을 이용한 인장, 압축, 굽힘 및 압렬시험을 실시하여 Babel과 Sines의 2축응력장해소이론과 연삭숫돌의 파괴조건을 관련시켜 평가함과 동시에, 이 때 검출되는 AE 신호 처리 파라미터(Parameter) 로부터 연삭숫돌의 자인자가 파괴강도 및 AE특성에 미치는 영향을 구명하여 파괴의 예지및 연삭숫돌수명의 예측가능성등의 파괴강도특성을 평가고찰하였다.

• Journal of Radiation Protection and Research
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• 제2권1호
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• pp.24-30
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• 1977

P.W.R. 형 원자로 증기발생기에서 발생되는 배수는 방사성 물질에 의하여 오염된다. 일반적으로 이 원자로의 증기발생기에 공급되는 급수는 'Phosphate'로 pH를 조절했으나 근래에는 'Ammonia' 조절방법이 선진제국에서 각광을 받고 있는 실정인 바 이는 약알카리로 pH를 조절하여 장치의 부식을 방지하기 위함이다. 본 실험에서는 이온 교환 수지탑을 이용하여 'Ammonia'로 조절된 배수를 처리하는 실험을 하였는 바, Acid Form의 Carboxylic, Cationic 몇 Anionic Ion Exchange Resinces Columns의 직열상태로 운전하였을 시 $^{137}Cs$과 $^{90}Sr$의 제염계수(Decontamination Factor)가 가장 높은 값을 나타낼 수 있으며 또한 그 처리능력이 가장 양호한 편으로 판명되었다.

• Molecules and Cells
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• 제44권11호
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• pp.805-829
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• 2021

CCCTC-binding factor (CTCF) critically contributes to 3D chromatin organization by determining topologically associated domain (TAD) borders. Although CTCF primarily binds at TAD borders, there also exist putative CTCF-binding sites within TADs, which are spread throughout the genome by retrotransposition. However, the detailed mechanism responsible for masking the putative CTCF-binding sites remains largely elusive. Here, we show that the ATP-dependent chromatin remodeler, chromodomain helicase DNA-binding 4 (CHD4), regulates chromatin accessibility to conceal aberrant CTCF-binding sites embedded in H3K9me3-enriched heterochromatic B2 short interspersed nuclear elements (SINEs) in mouse embryonic stem cells (mESCs). Upon CHD4 depletion, these aberrant CTCF-binding sites become accessible and aberrant CTCF recruitment occurs within TADs, resulting in disorganization of local TADs. RNA-binding intrinsically disordered domains (IDRs) of CHD4 are required to prevent this aberrant CTCF binding, and CHD4 is critical for the repression of B2 SINE transcripts. These results collectively reveal that a CHD4-mediated mechanism ensures appropriate CTCF binding and associated TAD organization in mESCs.