• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.3
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• pp.160-180
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• 2012

We have studied the eukaryotic plankton species diversity to compare the community structure of fresh and brackish waters in the lower reaches of the Nakdong River using metagenomic methods. We constructed 18S rDNA clone libraries of total DNAs extracted from environmental water samples collected at Mulgeum (MG100929, fresh) and Eulsukdo bridge (ES, brackish). Through the steps of colony PCR, PCR-RFLP, sequencing and similarity analysis, we discovered the diverse species composition of eukaryotic plankton. Total 338 clones (170 at MG100929 and 168 at ES) were analyzed, and then we found 74 phylotypes (49 for MG100929 and 25 for ES). From the phylogenetic analysis, we confirmed various eukaryotic plankton of broad range of taxonomic groups, including Stramenopiles, Cryptophyta, Viridiplantae, Alveolata, Rhizaria, Metazoa, and Fungi. We also found several unreported species in Korea and candidates of new taxonomic entities at levels higher than genus. Especially, the cryptic species diversity including unreported phylotypes of Pirsonia (Stramenopiles) and Perkinsea (Alveolata) suggests that the molecular monitoring method can produce new informative biological data in monitoring the changes in the Nakdong River Mouth ecosystem.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.210-215
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• 2014

Pseudomonas nitroreducens TX1 was isolated from a rice field drainage in Taiwan. The bacterium is of special interest because of its capability to use a group of nonionic surfactants such as alkylphenol polyethoxylates even at high concentrations as a sole carbon source. In this study, a small cryptic circular plasmid, pTX1, was characterized from P. nitroreducens TX1. It is 2,286 bp in length with a GC content of 63.3% and harbors three open reading frames, $Rep_{pTX1}$ and functionally unidentified ORF1 and ORF2. The predicted $rep_{pTX1}$ gene product is homologous to Rep proteins of plasmids belonging to the pC194/pUB110 family, which is predominantly found in Gram-positive bacteria and is known to replicate by the rolling-circle mechanism. The copy number of pTX1 was estimated to be about 150 in each cell. Based on the genetic fingerprints and comparison with other plasmids, it is concluded that pTX1 replicates by a rolling circle mechanism which is rarely found for Pseudomonas plasmids.

• Journal of Genetic Medicine
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• v.8 no.2
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• pp.135-138
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• 2011

The authors of the present study report the prenatal detection of a chromosomal abnormality with additional satellites on the distal short arm of chromosome 8. A 35-year-old woman was referred for amniocentesis because of her advanced maternal age and positive result for maternal serum screening test. Cytogenetic analysis of cultured amniocytes showed a satellite 8p chromosome. The satellite 8p chromosome was positive for nucleolus organizer region (NOR) staining. The parents' karyotypes were normal. Fluorescence in situ hybridization (FISH) study for metaphases of fetal amniocytes revealed a cryptic translocation of chromosomes 8p and 22p. The fetal karyotype was described as 46,XY,8ps.ish t(8;22)(p23.3;p11.2) (D8S504-;D8S504+)dn. The parents decided to continue the pregnancy and a phenotypically normal boy was born at 38 weeks of gestation. In case of de novo terminal NORs detected prenatally, more accurate cytogenetic and molecular analysis should be performed in order to rule out cryptic chromosomal rearrangement among other chromosomes.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.660-661
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• 2006

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.534-534
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• 2003

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.331-331
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• 2005

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.153-153
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• 2005

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.78-78
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• 2000

• Journal of Internet Computing and Services
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• v.17 no.5
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• pp.97-110
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• 2016

Cryptanalysis is very important step for auditing and checking strength of any cryptosystem. Some of these cryptosystem ensures confidentiality and security of large information exchange from source to destination using symmetric key cryptography. The cryptanalyst investigates the strengths and identifies weakness key as well as enciphering algorithm. With increase in key size the time and effort required to guess the correct key increases so trend is increase key size from 8, 16, 24, 32, 56, 64, 128 and 256 bits to strengthen the cryptosystem and thus algorithm continues without compromise on the cost of time and computation. Automatic Variable Key (AVK) approach is an alternative to the approach of fixing up key size and adding security level with key variability adds new dimension in the development of secure cryptosystem. Likewise, whenever any new cryptographic method is invented to replace per-existing vulnerable cryptographic method, its deep analysis from all perspectives (Hacker / Cryptanalyst as well as User) is desirable and proper study and evaluation of its performance is must. This work investigates AVK based cryptic techniques, in future to exploit benefits of advances in computational methods like ANN, GA, SI etc. These techniques for cryptanalysis are changing drastically to reduce cryptographic complexity. In this paper a detailed survey and direction of development work has been conducted. The work compares these new methods with state of art approaches and presents future scope and direction from the cryptic mining perspectives.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.101-108
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• 2000

The liverwort Pellia borealis is a diploid, monoecious, allopolypliod species (n=18) that as it was postulated, originated after hybridization and duplication of chromosome sets of two cryptic species: Pellia epiphylta-species N (n=9) and Pellia epiphylla-species 5 (n=9). Our recent results have supported the allopolyploid origin of P.borealis. We have shown that the nuclear genome of P.borealis consists of two nuclear genomes: one derived from P.epiphylla-species N and the other from P.epiphylla-species 5. In this paper we show the origin of chloroplast and mitochondrial genomes in an allopolyploid species P.borealis. To our knowledge there is no information concerning the way of mitochondria and chloroplast inheritance in Brophyta. Using an allopolyploid species of p. borealis as a model species we have decided to look into chloroplast and mitochondrial genomes of P.borealis, P.epiphylla-species N and P.epiphylla-species S for nucleotide sequences that would allow us to differentiate between both cryptic species and to identify the origin of organelle genomes in the alloploid species. We have amplified and sequenced a chloroplast $tRNA^{Leu}$ gene (anticodon UAA) containing an intron that has shown to be highly variable in a nucleotide sequence and used for plant population genetics. Unfortunately these sequences were identical in all three liverwort species tested. The analysis of the nucleotide sequence of chloroplast, an intron containing $tRNA^{Gly}$ (anticodon UCC) genes, gave expected results: the intron nucleotide sequence was identical in the case of both P.borealis and P.epiphyllaspecies N, while the sequence obtained from P.epiphyllasperies S was different in several nucleotide positions. These results were confirmed by the nucleotide sequence of another chloroplast molecular marker the chloroplast, an intron-contaning $tRNA^{Lys}$ gene (anticodon UUU). We have also sequenced mitochondrial, an intron-containing $tRNA^{Ser}$ gene (anticodon GCU) in all three liverwort species. In this case we found that, as in the case of the chloroplast genome, P.borealis mitochondrial genome was inherited from P.epiphylla-species N. On the basis of our results we claim that both organelle genomes of P.borealis derived from P.epiphylla-species N.