• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1890-1894
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• 2008

Apoemulsan is a biopolymer with potent emulsification activity, produced by Acinetobacter venetian us RAG-1 (RAG-1). The wee gene cluster is responsible for apoemulsan biosynthesis. The analysis of (i) a putative polysaccharide copolymerase mutant (${\Delta}wzc$), (ii) a putative polymerase mutant (${\Delta}wzy$), and (iii) an apoemulsan-deficient variant (${\Delta}2$) indicated that the wee gene cluster controls the synthesis of two polysaccharides: high molecular weight (HMW) and low molecular weight (LMW). LMW polysaccharide of wee origin was present in LPS isolated from RAG-1 cells, suggesting a link to the Lipid A-core of LPS molecules. SDS-PAGE analysis indicated that apoemulsan is copurified with LPS polysaccharide, with implications in the emulsification activity of RAG-1 polymer.

• Journal of Life Science
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• 제9권1호
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• pp.1-4
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• 1999

Large-scale deletions of mitochondrial DNA(mtDNA) have been documented in patients with mitochondrial myopathies and seem to be especially frequent in patients with Kearns-Sayre syndrome (KSS). About one third of all patients shows a 4,977 bp deletion, known as the "common deletion", that removes a segment of DNA that includes several genes encoding for respiratory chain subunits. In this disorder, the population of deleted mtDNA molecules coexists with population of normal, wild-type full length mtDNAs, a situation known as heteroplasmy. We have performed polymerase chain reaction (PCR) on paraffin-embedded muscle tissues from two korean KSS patients. The PCR analysis revealed the existence of two amplified fragments, the deleted fragments, the deleted fragment of 123 bp characteristic for common deletion and the wild-type fragment of 152 bp.of 152 bp.

• Journal of Life Science
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• 제9권1호
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• pp.5-8
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• 1999

Helicobacter pylori is the etiologic agent of human gastritis and peptic ulceration and produces urease as the major protein component on its surface. H. pylori urease is known to serve as a major virulence factor and a potent immunogen. Deletion mutageneses were performed in the H. pylori urease accessory genes by using combinations of restriction enzymes and other DNA modifying enzymes in order to assess the function of these accessory gene products in the expression of the active urease. Selective disruptions in the accessory gene regions resulted in complete abolishment of the urease activity, which is consistent with other bacterial ureases. Interestingly, deletions in ureE-containing regions caused reduced expression of the structural enzyme subunits.

• 말소리와 음성과학
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• 제3권3호
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• pp.115-121
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• 2011

This paper examines how L2 speech production varies according to learner's L2 proficiency level. L2 speech production variations are analyzed by quantitative measures at word and phone levels using Korean learners' English corpus. Word-level variations are analyzed using correctness to explain how speech realizations are different from the canonical forms, while accuracy is used for analysis at phone level to reflect phone insertions and deletions together with substitutions. The results show that speech production of learners with different L2 proficiency levels are considerably different in terms of performance and individual realizations at word and phone levels. These results confirm that speech production of non-native speakers varies according to their L2 proficiency levels, even though they share the same L1 background. Furthermore, they will contribute to improve non-native speech recognition performance of ASR-based English language educational system for Korean learners of English.

• Journal of Electrical Engineering and information Science
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• 제2권4호
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• pp.37-45
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• 1997

With rapid increase of information requirements from various application areas, there has been much research on dynamic information storage structures that effectively support insertions, deletions and updates. In this appear we evaluate the performance of he existing dynamic signature file methods such as the S-tree, Quick Filter and HS file and provide guidelines for the most effective usage to a given operational environment. We derive analytic performance evaluation models of the storage structures based on retrieval time, storage overhead and insertion time. We also perform extensive experiments with various data distributions such as uniform, normal and exponential distributions. The relationships among various performance parameters are throughly investigated. We show through performance comparison based on analytic models and experiments that regardless of data distribution, the HS file significantly improves performance in both the retreival time and the storage overhead over S-tree and Quick Filter.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2006년도 Principles and Practice of Microarray for Biomedical Researchers
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• pp.125-126
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• 2006

NimbleGen has developed strategies to use its high-density oligonucleotide microarray platform (385,000 probes per array) to map both promoter binding sites and copy number variation at very high-resolution in the human genome. Here we describe a genome-wide map of active promoters determined by experimentally locating the sites of transcription imitation complex binding throughout the human genome using microarrays combined with chromatin immunoprecipitation. This map defines 10,567 active promoters corresponding to 6,763 known genes and at least 1,196 un-annotated transcriptional units. Microarray-based comparative genomic hybridisation (CGH) is animportant research tool for investigating chromosomal aberrations frequently associated with complex diseases such as cancer, neuropsychiatric disorders, and congenital developmental disorders. NimbleGen array CGH is an ultra-high resolution (0.5-50 Kb) oligo array platform that can be used to detect amplifications and deletions and map the associated breakpoints on the whole-genome level or with custom fine-tiling arrays. For whole-genome array CGH, probes are tiled through genic and intergenic regions with a median probe spacing of 6 Kb, which provides a comprehensive, unbiased analysis of the genome.

• Journal of Microbiology
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• 제38권2호
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• pp.62-65
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• 2000

Partial sequence comparisons of mitochondrial small subunit rDNA (mt SSU rDNA) were used to examine taxonomic and evolutionary relationships among seven Penicillium species : two monoverticillate species, two biverticillate species, and three terverticillate species. Amplified fragments of mt SSU rDNA highly varied among seven species in size, suggesting the existence of multiple insertions or deletions in the region. A phylogengtic tree was constructed by exhaustive search of parsimony analysis. The phylogenetic tree distinguished two statistically supported monophyletic groups, one for two monoverticillate species and the other for three terverticillate species and ont biverticillate species, P. vulpinum. The phylogenetic relationship of P. waksmanii, the biverticillate species, was not clear.

• Journal of Genetic Medicine
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• 제7권1호
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• pp.1-8
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• 2010

Hemophilia A is a sex-linked recessive coagulation disorder associated with diverse mutations of the factor VIII gene and a variety of phenotypes. The type of mutation involved dictates the activity of factor VIII, and in turn the severity of bleeding episodes and development of alloantibodies against factor VIII (inhibitors). Missense mutations are the most common genetic risk factors for hemophilia A, especially mild to moderate cases, but carry the lowest risk for inhibitor development. On the other hand, intron 22 inversion is the most common mutation associated with severe hemophilia A and is associated with high risk of inhibitor formation. Large deletions and nonsense mutations are also associated with high risk of inhibitor development. Additional mutations associated with hemophilia A include frameshift and splice site mutations. It is therefore valuable to assess the mutational backgrounds of hemophilia A patients in order to to interpret their symptoms and manage their health problems.

• Journal of Information Processing Systems
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• 제14권3호
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• pp.631-644
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• 2018

Many studies on flash memory-based buffer replacement algorithms that consider the characteristics of flash memory have recently been developed. Conventional flash memory-based buffer replacement algorithms have the disadvantage that the operation speed slows down, because only the reference is checked when selecting a replacement target page and either the reference count is not considered, or when the reference time is considered, the elapsed time is considered. Therefore, this paper seeks to solve the problem of conventional flash memory-based buffer replacement algorithm by dividing pages into groups and considering the reference frequency and reference time when selecting the replacement target page. In addition, because flash memory has a limited lifespan, candidates for replacement pages are selected based on the number of deletions.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.109-110
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• 2003

To validate a novel mouse model, gpt delta, for in vivo mutagenesis, the Mammalian Mutagenesis Society (MMS), a subgroup of the Environmental Mutagen Society of Japan (JEMS) (JEMS/MMS), performed a collaborative study as the third trial for transgenic animal assay. In this mouse model, point mutations and deletions re separately identified by gpt (6-thioguanine-resistant) and Spi- (sensitive to P2 interference) selections, respectively.(omitted)