• 생명과학회지
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• 제11권5호
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• pp.400-404
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• 2001

최근 새로운 인간 내생 레트로바이러스 패밀리(HERAV-S)가 인간의 X 염색체상에서 동정 되었다. 그 길이는 6.7kb 이며 LTR-gag-pol-env-LTR의 일반적인 레트로바이러스의 구조를 가졌다. PCR 방법과 염기서열분석을 통하여 인간 게놈 DNA에서 HERV-S LTR 패밀리를 동정하였다. 네 개의 LTR엘리먼트(HSL-1, HSL-5, HSL-10, HSL-11)가 동정 되었으며, 이들은 HERV-S LLR 패밀리는 영장류의 진화과정에서 진화적인 분기를 통해 주된 2개의 그룹으로 나뉘어졌다. 영장류에서 이러한 HERV-S LTR들의 연구가 이루어진다면 이들의 영장류 게놈 내의 삽입시기를 알 수 있고 또한 인류의 진화를 이해하는데 크게 이바지 할 것이다.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.40-47
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• 2001

In this pater, the QLQG/LTR control method is applied for the position control of the nonlinear timing belt driving sys-tem. Parameters fo the plant are identified by genetic algorithm and nonlinear elements, such as Coulomb friction and dead-zone, and quasi-linearized by RIDE method. Comparing with the LQG/LTR contro. the QLQG/LTR has similar structures of the LQG/LTR, but this method can consider nonlinear effects in designing the controller. Thus, the QLQG/LTR control system is robust to hard nonlinearities such as Coulomb friction, dead-zone, etc. Forma given hard non-linear system through experiments, it is shown that the tracking performance of the QLQG/LTR control system can be very improved that the LQF/LTR control system.

• Animal cells and systems
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• 제6권2호
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• pp.167-170
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• 2002

The long terminal repeats (LTRs) of human endogenous retrovirus (HERV) have been found to be coexpressed with sequences of closely located genes. It has been suggested that the LTR elements have contributed to the structural change or genetic variation of human genome connected to various diseases and evolution. We examined the HERV-W LTR elements in various cancer cells (2F7, A43l , A549, HepG2, MIA-PaCa-2, PC-3, RT4, SiHa, U-937, and UO-31). Using genomic DNA from the cancer cells, we performed PCR amplification and identified twelve new HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (88-99％) with HERV-W LTR (AF072500). A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-W LTR elements could be mainly divided into two groups through evolutionary divergence. Three HERV-W LTR elements (RT4-2, A43l-1, and UO3l-2) belonged to Group 1, whereas nine LTR elements (2F7-2, A549-1, A549-3, HepG2-3, MP2-2, PC3-1, SiHa-8, SiHa-10, and U937-1) belonged to Group 11. Taken together, our new sequence data of the HERV-W LTR elements may contribute to an understanding of tissue-specific cancer by genomic instability of LTR integration.

• 한국정밀공학회지
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• 제10권4호
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• pp.118-127
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• 1993

A nonlinear control design method called the QJQG/LTR method is presented for the depth control of underwater vehicles with the deadzone of the flow control valve. And, it is shown how the design plant model can be formulated in the QLQG/LTR depth control system design for underwater vehicles which have the triple integrator. In order to show the effectiveness of this control system, the linear LQG/LTR control system neglected the deadzone effect and the nonlinear QLQG/LTR control system considered it are compared. It is found that the QLQG/LTR control system is relatively insensitive to the input magnitude, even if there exists a hard nonlinearity in the plant.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.508-513
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• 2002

Human endogenous retroviral long terminal repeats (LTRs) have been found to be coexpressed with sequences of genes located nearby. It has been suggested that the LTR elements have contributed to the structural change or genetic variation of human genome connected to various diseases. The HERV-W family has been identified in the cerebrospinal fluids and brains of individuals with schizophrenia. Using a cDNA library derived from a human brain, the HERV-W LTR elements were examined and five new LTR elements were identified. These elements were examined using a YAC clone panel from the Xq21.3 region linked to psychosis that was replicated on the Y chromosome after the separation of the chimpanzee and human lineages. Fourteen elements of the HERV-W LTR were identified in that region. Those LTR elements showed a high degree of sequence similarity ($91.8-99.5\%$) with previously reported HERV-W LTR. A phylogenetic tree obtained from the neighbor-joining method revealed that new HERV-W LTR elements were closely related to the AXt000960, AF072504, and AF072506 from the GenBank database. The data indicates that several copy numbers of the HERV-W LTR elements exist on the Xq21.3 region and are also expressed in the human brain. These LTR elements need to be further investigated as potential leads to neuropsychiatric diseases.

• 약학회지
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• 제52권2호
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• pp.125-130
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• 2008

The long terminal repeat (LTR) of retroviral DNA genome plays an important role in the integration process by providing substrate recognition site for viral integrase (IN). The dinucleotide CA near the 3'-end of the LTR termini is completely conserved among retoviruses. In order to study specificity of interaction between prototype foamy virus (PFV) IN and its U5 LTR DNA, the effect of mutagenesis of the CA sequence was investigated by studying reactivity of PFV IN to the mutant LTR substrates. Replacement of only the C or the A allowed 60 to 100% of the reactivity of the wild type LTR substrate. In addition, replacement of the C and the A showed 50 to 80% of the reactivity of the wild type LTR substrate, indicating that PFV IN has less specificity on the conserved CA sequence when it is compared to the other retroviral INs. Therefore it is suggested that PFV IN is less dependent on the conserved sequence of LTR termini for its enzymatic reaction.

• Journal of Life Science
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• 제10권1호
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• pp.32-36
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• 2000

Solitary long terminal repeats(LTRs) of human endogenous retrovirus K family(HERV-K) have been found to be coexpressed with sequences of closely located genes. It has been suggested that HERV-K LTR-like elements entered the primate genome approximately 33-40 million years ago. WE investigated the presence of HERV-K LTR elements in New World monkeys using PCR amplification. Six LTR elements of HERV-K family were identified from New World monkeys, represented by the squirrel and night monkeys. They showed a high degree of sequence homology(96-99%) with the human-specific HERV-K LTR elements. Phylogenetic analysis reveals that an LTR element (SM-1) from the squirrel monkey and another LTR element (NM-1) from the night monkey are very closely related to the human-specific HERV-K LTR elements with low degree of divergence. This finding suggests that some of LTR elements of HERV-K family have recently been proliferated in New World monkeys. A sequence in chromosome Xq26(AL034407) \ulcorner contains an HERV-K LTR element was shown to be present in the human genome, but is absent in the bonobo, chimpanzee, gorilla, orangutan, and gibbon. It has more than 99% homology to other human-specific HERV-K LTR elements. This sequence thus represents and isolated insertion of an evolving class of elements that may have made a particular contribution to human genomic plasticity.

• 전자공학회논문지S
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• 제36S권2호
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• pp.38-45
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• 1999

본 논문에서는, $H_{\infty}-LTR$ 설계의 새로운 접근방법을 제시한다. 제시된 방법은 제어입력의 크기 및 회복오차의 적절한 가중을 조절할 수 있는 설계도구를 제공한다. 1단계에서, 요구되는 성능사양에 만족하도록 루프를 정형하기 위하여 Kalman 필터를 설계하고, 설계된 Kalman 필터는 플랜트의 전달함수와 함께 목표전달함수(target transfor function)로 사용된다. 2단계에서는 목표전달함수로 회복을 위하여 감도함수를 가중함수로 상요한 준 최적 $H_{\infty}_LTR$을 설계한다. 시뮬레이션을 통하여 LQG/LTR, $H_{\infty}-LTR$ 방법의 경과를 비교함으로써 제시된 $H_{\}-LTR$의 우수성을 보인다.

• Journal of Life Science
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• 제11권2호
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• pp.83-86
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• 2001

The long terminal repeat (LTR) elements of human endogenous retrovirus (HERV) have been found to be coexpressed with genes located nearby. It has been suggested that the LTR elements have contributed to the genetic variation of human genome connected to various diseases. Recently, HERV-W family was identified in the cerebrospinal fluids and brains of individuals with schizophrenia. Using genomic DNAs derived from schizophrenia, we performed PCR amplification and identified six HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (87.7-99.5%) with HERV-W LTR (AF072500). Sequence analysis of the HERV-W LTR elements revealed that clone W-sch1 showed identical sequence with the AC003014 (PAC clone RP1-290B4) derived from human Xq23. Clone W-sch2 was closely related to the AC0072442 derived from human Y chromosome by phylogenetic analysis. Our data suggest that new HERV-W LTR elements in schizophrenia may be very useful for further studies to understand neuropsychiatric diseases.

• 한국통신학회논문지
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• 제16권10호
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• pp.981-991
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• 1991

LQG의 강인성 증진을 위하여 제안된 LGQ/LTR방법은 비 최소위상 플랜트에 대하여 적용할 수 없는 이론적 제한성을 갖는다. 본 논문에서는 비 최소위상 플랜트에 대해서도 적용될 수 있는 세 단계로 구성된 새로운 LQG/LTR방법을 제안한다. 첫번째 단계로 주어진 비 최소위상 플랜트를 최소위상 플랜트로 근사화 시키기 위한 부가적인 feed-forward 보상기를 설계하며 다음 단계에서 전개사양에 맞도록 근사화된 비 최소위상 플랜트에 대하여 목표 루우프를 설계한다. 마지막 단계로 개루우프의 전달함수가 목표 루우프로 회복시키는 LTR을 설계한다. 제안된 방법이 비 최소위상 플랜트에 대한 제약을 해결할 수 있음을 시뮬레이션 예제를 통하여 보인다.