• 정보보호학회논문지
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• 제11권6호
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• pp.41-51
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• 2001

그룹 서명 기법은 익명성을 보장해주면서 그룹 구성원들로 하여금 그룹을 대표해서 서명을 할 수 있도록 하는 방법으로 분쟁이 발생하는 경우에는 지정된 그룹 관리자만이 구성원의 신원을 확인할 수 있다. 최근 수 년 동안, 그룹 서명 기법은 집중적으로 연구되어 왔으며 다양한 응용분야에 적용되고 있다. 그러나 그룹의 구성원이 소속된 그룹에서 탈퇴하기를 원하거나 불법행위 등의 이유로 그룹에서 강제 탈퇴되어야 하는 경우가 발생했을 때, 이 상황에 적합한 방법이 구체적으로 제시되어 있지 않다. [3]에서 언급한 바에 의하면 구성원 탈퇴에 따른 복잡도는 그룹 서명을 실생활에 적용하는데 있어 걸림돌이며 따라서 시급히 해결해야 할 문제이다. 이 논문에서 그룹 공개키와 서명 길이는 그룹 크기에 독립적이면서 구성원의 자유로운 탈퇴를 허용하는 효율적인 그룹 서명 기법을 제안한다. 제안한 그룹 서명 기법의 안전성은 RSA 가정에 기반하고 있다. 더 나아가 특정한 구성원이 생성한 서명을 추적해 낼 수 있는 방법도 더불어 제안한다.

• 영어영문학
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• 제56권5호
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• pp.851-870
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• 2010

The purpose of this paper is to investigate the distribution of /ju/ in British English, especially after the coronal sonorants /n, l, /r/. The sequence /ju/ is related with vowels such as /u/, /ʊ/, and /ʊ/, and has occasioned a variety of conflicting analyses or suggestions. One of those is in which context /j/ is deleted if we suppose that the underlying form is /ju/. The context differs according to the dialect we deal with. In British English, it is known that /j/ is deleted always after /r/, and usually after /l/ when it occurs in an unstressed word-medial syllable. To check this well-known fact I searched OED Online (the 2nd Edition, 1989) for those words which contain /n, l, r/ + /ju, jʊ, u, ʊ, (j)u, (j)ʊ/ in their pronunciations, using the search engine provided by OED Online. After removing some unnecessary words, I classified the collected words into several groups according to the preceding sonorant consonants, the positions, and the presence (or absence) of the stress, of the syllable where /ju/ occurs. The results are as follows: 1) the deletion of /j/ depends on the sonorant consonant which /ju/ follows, the position where it occurs, and the presence of the stress which /ju/ bears; 2) though the influence of the sonorant consonants is strong, the position and stress also have non-trivial effect on the deletion of /j/, that is, the word-initial syllable and the stressed syllable prefer the deletion of /j/, and word-medial and unstressed syllable usually retain /j/; 3) the stress and position factors play their own roles even in the context where the effect of /n, l, r/ is dominant.

• Mycobiology
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• 제51권5호
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• pp.372-378
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• 2023

Lkh1, a LAMMER kinase homolog in the fission yeast Schizosaccharomyces pombe, acts as a negative regulator of filamentous growth and flocculation. It is also involved in the response to oxidative stress. The lkh1-deletion mutant displays slower cell growth, shorter cell size, and abnormal DNA content compared to the wild type. These phenotypes suggest that Lkh1 controls cell size and cell cycle progression. When we performed microarray analysis using the lkh1-deletion mutant, we found that only four of the up-regulated genes in the lkh1-deletion were associated with the cell cycle. Interestingly, all of these genes are regulated by the Mlu1 cell cycle box binding factor (MBF), which is a transcription complex responsible for regulating the expression of cell cycle genes during the G1/S phase. Transcription analyses of the MBF-dependent cell-cycle genes, including negative feedback regulators, confirmed the up-regulation of these genes by the deletion of lkh1. Pull-down assay confirmed the interaction between Lkh1 and Yox1, which is a negative feedback regulator of MBF. This result supports the involvement of LAMMER kinase in cell cycle regulation by modulating MBF activity. In vitro kinase assay and NetPhosK 2.0 analysis with the Yox1T40,41A mutant allele revealed that T40 and T41 residues are the phosphorylation sites mediated by Lkh1. These sites affect the G1/S cell cycle progression of fission yeast by modulating the activity of the MBF complex.

• 미생물학회지
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• 제54권1호
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• pp.9-17
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• 2018

저온 환경에서의 생장에 영향을 주는 지방산 합성 관련 유전자 bkdR, sigL, yplP, des들의 역할을 알아보기 위하여 각각 유전자들이 상실된 Bacillus subtilis CU1065와 JH642 돌연변이들을 제조하였다. 이들 유전자들의 저온 민감성을 확인하기 위해 $37^{\circ}C$와 $15^{\circ}C$에서 세포들의 생장을 측정하였다. $37^{\circ}C$에서 야생형과 결실 돌연변이 균주는 거의 유사한 정도의 생장을 보였으나, $15^{\circ}C$에서 오직bkdR 결실 돌연변이만이 야생형에 비해 매우 느린 생장이 관찰되었으며 sigL, yplP 결실의 경우 야생형에 비해 다소 느리거나 유사한 생장을 보였다. bkdR, sigL, yplP 결실에 대한 이중, 삼중 돌연변이를 만들어 LB agar에서 $20^{\circ}C$로 키워 저온생장을 조사한 결과, bkdR 결실이 포함되지 않은 어떤 이중, 삼중 결실들에서는 저온에 민감한 생장을 보이지 않았다. 온도 민감성 특성을 보다 잘 알아보기 위하여 $37^{\circ}C$에서 $OD_{600}=0.4$까지 키워 $15^{\circ}C$로 온도를 내리는 저온충격 조건에서 생장하는 실험을 진행하였다. 이 실험에서 오직bkdR 결실 돌연변이만이 현저히 낮은 생장을 보였으며 추가적인 des 결실은 저온 민감성을 증가시킨다. bkdR은 branched-chain fatty acid을 합성하는 전구물질인 isoleucine, valine, leucine 아미노산을 생산하는 bkd operon을 활성화한다. bkdR 결실 돌연변이의 저온생장에서 이들 아미노산의 저온생장에 미치는 영향을 조사한 결과 isoleucine은 bkdR 결실에 대한 저온 민감성을 회복시켜주나 valine은 저온 민감성을 회복시켜 주지 못하는 결과를 보였다. isoleucine은 분해되어 anteiso-branched 지방산 합성의 전구물질로 만들어지는 반면에, valine은 iso-branched 지방산 합성의 전구물질로 만들어진다. 따라서 저온생장에서 branched-chain fatty acid 중 anteiso-branched 지방산이 중요한 역할을 하고 있음을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1526-1531
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• 2014

Matrix metalloproteinases (MMP) are key enzymes involved in cell and tissue remodeling during ovarian follicle development and ovulation. The control of MMP9 transcription in ovarian follicles occurs through a core promoter region (-2,400 to -1,700 bp). The aim of this study was to screen genetic variations in the core promoter region and examine MMP9 transcription regulation and reproduction performance. A single cytosine deletion/insertion polymorphism was found at -1954 $C^+/C^-$. Genetic association analysis indicated significant correlation between the deletion genotype ($C^-$) with total egg numbers at 28 weeks (p = 0.031). Furthermore, luciferase-reporter assay showed the deletion genotype ($C^-$) had significantly lower promoter activity than the insertion genotype ($C^+$) in primary granulosa cells (p<0.01). Therefore, the identified polymorphism could be used for marker-assisted selection to improve chicken laying performance.

• Genomics & Informatics
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• 제8권4호
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• pp.177-184
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• 2010

The target of rapamycin (TOR) signaling pathway is a conserved pathway that regulates eukaryotic cell growth in response to environmental cues. Chemical genomic approaches that profile rapamycin sensitivity of yeast deletion strains have given insights into the function of TOR signaling pathway. In the present study, we analyzed the rapamycin sensitivity of yeast deletion library strains on synthetic medium. As a result, we identified 130 strains that are hypersensitive or resistant to rapamycin compared with wild-type cells. Among them, 36 genes are newly identified to be related to rapamycin sensitivity. Moreover, we found 16 strains that show alteration in rapamycin sensitivity between complex and synthetic media. We suggest that these genes may be involved in part of TOR signaling activities that is differentially regulated by media composition.

• BMB Reports
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• 제48권3호
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• pp.184-189
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• 2015

Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) is known to protect neurons from neurodegeneration during ischemia/reperfusion injury. We recently reported that ROS-mediated oxidative stress promotes phosphorylation of endogenous SHP-2 in astrocytes and complex formation between caveolin-1 and SHP-2 in response to oxidative stress. To examine the region of SHP-2 participating in complex formation with caveolin-1, we generated three deletion mutant constructs and six point mutation constructs of SHP-2. Compared with wild-type SHP-2, binding of the N-SH2 domain deletion mutant of SHP-2 to p-caveolin-1 was reduced greatly, using flow cytometric competitive binding assays and surface plasmon resonance (SPR). Moreover, deletion of the N-SH2 domain of SHP-2 affected $H_2O_2$-mediated ERK phosphorylation and Src phosphorylation at Tyr 419 in primary astrocytes, suggesting that N-SH2 domain of SHP-2 is responsible for the binding of caveolin-1 and contributes to the regulation of Src phosphorylation and activation following ROS-induced oxidative stress in brain astrocytes.

• Clinical and Experimental Pediatrics
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• 제57권7호
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• pp.333-336
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• 2014

Reports of constitutional ring chromosome 22, r(22) are rare. Individuals with r(22) present similar features as those with the 22q13 deletion syndrome. The instability in the ring chromosome contributes to the development of variable phenotypes. Central nervous system (CNS) atypical teratoid rhabdoid tumors (ATRTs) are rare, highly malignant tumors, primarily occurring in young children below 3 years of age. The majority of ATRT cases display genetic alterations of SMARCB1 (INI1/hSNF5 ), a tumor suppressor gene located on 22q11.2. The coexistence of a CNS ATRT in a child with a r(22) is rare. We present a case of a 4-month-old boy with 46,XY,r(22)(p13q13.3), generalized hypotonia and delayed development. High-resolution microarray analysis revealed a 3.5-Mb deletion at 22q13.31q13.33. At 11 months, the patient had an ATRT ($5.6cm{\times}5.0cm{\times}7.6cm$) in the cerebellar vermis, which was detected in the brain via magnetic resonance imaging.

• Journal of information and communication convergence engineering
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• 제5권4호
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• pp.339-345
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• 2007

Video transcoding is a technique used to convert a compressed input video stream with an arbitrary format, size, and bitrate into a different attribute video stream different attributes to provide a efficient video streaming service for the customers is dispersed in the heterogeneous networks. Specifically, frames deletion occur in a transcoding scheme that exploits the adjustment of frame rate, and at this time, the loss in temporal relation among frames due to frame deletion is compensated for the prediction of motion estimation by reusing motion vectors in the would-be deleted frames. But the processing time for transcoding don't have an improvement as much as our expectation because transcoding is done only within the transcoder. So in this paper, we propose a new transcoding algorithm based on prediction period to improve transcoding-related processing time. For this, we also modify the existing encoder so as to adjust dynamically frame rate based on the prediction period and deletion period of frames. To check how the proposed algorithm works nicely, we implement a video streaming system with the new transcoder and encoder to which it is applied. The result of the performance test shows that the streaming system with proposed algorithm improve 60% above in processing time and also PSNR have a good performance while the quality of pictures is preserved.

• BMB Reports
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• 제32권1호
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• pp.12-19
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• 1999

Gaegurin 4 (GGN4), a broad-spectrum antibiotic, is a 37-amino acid peptide isolated from the Korean frog, Rana rugosa. In this study, we have chemically synthesized and purified GGN4 analogues where the C-terminal portion is truncated and/or substituted with tryptophan. These peptides show significantly different biological activities depending on the location of tryptophan and the number of amino acids truncated from the C-terminal end. While deletion of 9 amino acids from the C-terminal seems to be marginally tolerable in maintaining the antimicrobial activity, further deletion of up to 14 amino acid residues decreases the potency by more than 60-fold towards Gram-positive, and 10-fold towards Gram-negative, bacteria. Surprisingly, the reduced activity of the shorter peptide can be completely restored by a single substitution of aspartic acid 16 to tryptophan 16 (D16W). Also, the truncation seems to decrease the specificity of antibiotic activity more towards Gram-positive than towards Gram-negative bacteria studied. These data suggest a partial role of the C-terminal region in determining the binding specificity and the activity of peptides upon binding to their target cell membranes.