• Title/Summary/Keyword: degenerate strain

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Bending Spring Model for Stable Strain-Based Dynamics in Triangular Meshes (삼각형 메쉬에서 안정적인 변형률 기반 동역학을 위한 굽힘 스프링 모델)

  • Kim, Jong-Hyun
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.01a
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    • pp.341-344
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    • 2022
  • 본 논문에서는 삼각형 메쉬 기반에서 변형률 기반 동역학(Strain-based dynamics, SBD)을 안정적으로 표현할 수 있는 굽힘 스프링 구조와 감쇠 기법에 대해 설명한다. SBD는 삼각형 메쉬의 에지 길이(Edge length) 기반의 에너지 대신 변형률(Strain)을 활용하여 에너지를 모델링한다. 하지만, 비정상적인 삼각형(Degenerate triangle)인 경우 변형률이 불안정하게 계산되어 잘못된 방향으로 늘어나는 문제가 발생한다. 본 논문에서는 이러한 문제를 효율적으로 처리할 수 있는 굽힘 스프링(Bending spring) 구조에 대해 소개한다. 결과적으로 본 논문에서 제안하는 기법은 안정적으로 SBD를 처리할 수 있기 때문에 다양한 재질의 옷감 시뮬레이션을 안정적으로 표현할 수 있도록 한다.

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Simulation of Stable Cloth on Triangular Mesh via LOD-Based Bending Springs on Strain-Based Dynamics

  • Jong-Hyun Kim
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.9
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    • pp.73-79
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    • 2023
  • This paper describes a level of detail (LOD) based bending spring structure and damping technique that can reliably represent strain-based dynamics (SBD) on a triangular mesh. SBD models elastic energy using strain instead of energy based on the edge length of a triangular mesh. However, when a large external force occurs, the process of calculating the elastic energy based on edges results in a degenerate triangle, which stretches in the wrong direction because it calculates an unstable strain. In this paper, we introduce an LOD-based bending spring generation and energy calculation method that can efficiently handle this problem. As a result, the technique proposed in this paper can reliably and efficiently handle SBD based on bending springs, which can provide a stable representation of cloth simulation.

Scratching Stimuli of Mycelia Influence Fruiting Body Production and ROS-Scavenging Gene Expression of Cordyceps militaris

  • Liu, Gui-Qing;Qiu, Xue-Hong;Cao, Li;Han, Ri-Chou
    • Mycobiology
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    • v.46 no.4
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    • pp.382-387
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    • 2018
  • The entomopathogenic fungus Cordyceps militaris is a valuable medicinal ascomycete, which degenerates frequently during subsequent culture. To avoid economic losses during industrialized production, scratching stimuli of mycelia was introduced to improve the fruiting body production. The present results indicated that higher yields and biological efficiency were obtained from two degenerate strains (YN1-14 and YN2-7) but not from g38 (an insertional mutant in Rhf1 gene with higher yields and shorter growth periods). Furthermore, the growth periods of the fruiting bodies were at least 5 days earlier when the mycelia were scratched before stromata differentiation. Three ROS-scavenging genes including Cu/Zn superoxide dismutase (CmSod1), Glutathione peroxidase (CmGpx), and Catalase A (CmCat A) were isolated and their expression profiles against scratching were determined in degenerate strain YN1-14 and mutant strain g38. At day 5 after scratching, the expression level of CmGpx significantly decreased for strain g38, but that of CmSod1 significantly increased for YN1-14. These results indicated that scratching is an effective way to promote fruiting body production of degenerate strain, which may be related at least with Rhf1 and active oxygen scavenging genes.

Nonlinear Analysis of RC Shell Structures Including Creep and Shrinkage Effects (크리프와 건조수축을 고려한 RC쉘 구조물의 비선형 해석)

  • 정진환;한충목;조현영
    • Magazine of the Korea Concrete Institute
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    • v.5 no.2
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    • pp.181-188
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    • 1993
  • In this study, a numerical method for the material nonlinear analysis of reinforced concrete shell structures including the time dependent effects due to creep and shrinkage is developed. Degenerate shell elements with the layered approach are used. The perfect or strain hardening plasticity model in compression and the linearly elastic model in tension until cracking for concrete are employed. The reinforcing bars are considered as a steel layer of equivalent thickness. Each :steel layer has an uniaxial behaviour resisting only the axial force in the bar direction. A bilinear idealization is adopted to model elasto-plastic stress-strain relationships. For the nonlinear anaysis, incremental load method combined with unbalanced load iterations for each load increment is used. To include time dependent effects of concrete, time domain is divided into several time steps which may have different length. Some numerical examples are presented to study the validity and applicability of the present method. The results are compared with experimental and numerical results obtained by other investigator.

Isolation of Cryptic Polyene Hydroxylase Gene in Rare Actinomycetes via Polyene-specific Degenerate PCR. (Polyene 특이적인 PCR에 의한 희소 방선균 유래 Cryptic Polyene Hydroxylase 유전자의 분리)

  • 박현주;명지선;박남실;한규범;김상년;김응수
    • Microbiology and Biotechnology Letters
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    • v.32 no.3
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    • pp.282-285
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    • 2004
  • The polyene antibiotics including nystatin, pimaricin, amphotericin and candicidin are a family of most promising antifungal polyketide compounds, typically produced by rare actinomycetes species. The biosynthetic gene clusters for these polyenes have been previously investigated, revealing the presence of highly homologous biosynthetic genes among polyene-producers such as polyketide synthase (PKS) and cytochrome P450 hydroxylase (CYP) genes. Based on amino acid sequence alignment among actinomycetes CYP genes, the highly-conserved regions specific for only polyene CYP genes were identified and chosen for degenerate PCR primers, followed by the PCR-screening with various actinomycetes genomic DNAs. Among tested several polyene non-producing actinomycetes strains, Pseudonorcardia autotrophica strain was selected based on the presence of PCR product with polyene-specific CYP gene primers, and then confirmed to contain a cryptic novel polyene hydroxylase gene in the chromosome. These results suggest that the polyene-specific hydroxylase gene PCR should be an efficient way of screening and isolating potentially-valuable cryptic polyene antibiotic biosynthetic genes from various microorganisms including rare actinomycetes.

Cloning of the Xylose Reductase Gene of Candida milleri

  • Sim, Hyoun-Soo;Park, Eun-Hee;Kwon, Se-Young;Choi, Sang-Ki;Lee, Su-Han;Kim, Myoung-Dong
    • Journal of Microbiology and Biotechnology
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    • v.23 no.7
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    • pp.984-992
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    • 2013
  • The entire nucleotide sequence of the xylose reductase (XR) gene in Candida milleri CBS8195 sourdough yeast was determined by degenerate polymerase chain reaction (PCR) and genome walking. The sequence analysis revealed an open-reading frame of 981 bp that encoded 326 amino acids with a predicted molecular mass of 36.7 kDa. The deduced amino acid sequence of XR of C. milleri was 64.7% homologous to that of Kluyveromyces lactis. The cloned XR gene was expressed in Saccharomyces cerevisiae, and the resulting recombinant S. cerevisiae strain produced xylitol from xylose, indicating that the C. milleri XR introduced into S. cerevisiae is functional. An enzymatic activity assay and semiquantitative reverse transcription-PCR revealed that the expression of CmXR was induced by xylose. The GenBank Accession No. for CmXR is KC599203.

Nucleotide Sequence of Coat Protein Gene of Kyuri Green Mottle Mosaic Virus Isolated from Zucchini

  • Lee, Su-Heon;Lee, Young-Gyu;Park, Jin-Woo;Park, Hong-Soo;Kim, Yeong-Tae;Cheon, Jeong-Uk;Lee, Key-Woon
    • The Plant Pathology Journal
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    • v.16 no.2
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    • pp.118-124
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    • 2000
  • The coat protein (CP) gene of kyuri green mottle mosaic virus zucchini strain (KGMMV-Z) isolated from zucchini (Cucurbita pepo) in Chonfu, Korea in 1999 was sequenced by the reverse transcription and polymerase chain reaction with degenerate and generate primers originated from tobamoviruses. The degenerate primers were very effective in amplification of KGMMV-Z CP region. The KGMMV-Z CP gene consisted of 486 nucleotides and had the same nucleotide length compared with those of cucurbit-infecting tobamoviruses. KGMMV-Z CP gene shared 43.8, 44.2, and 44.4% nucleotide sequence similarity with the CP gene of cucumber green mottle mosaic virus watermelon strain (CGMMZ-W), CGMMV-KW1, and CGMMV-SH, respectively, whereas three CGMMV strains among themselves showed 98.6-99.6% nucleotide similarity. The deduced amino acids of KGMMV-Z CP gene were 161 amino acid residues with the molecular weight of 17,181 daltons. The first 24 codons of KGMMV-Z CP gene corresponded to the sequences of the N-terminal amino acid of the viral capsid protein. The amino acid sequences of KGMMV-Z CP had 45.3% similarity compared with those of three CGMMV strains. However, the amino acid sequences of CGMMV strains were identical. These results showed that two cucurbit-infecting tobamovirus members, KGMMV-Z and CGMMV were genetically distantly related.

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Nonlinear vibration of functionally graded nano-tubes using nonlocal strain gradient theory and a two-steps perturbation method

  • Gao, Yang;Xiao, Wan-Shen;Zhu, Haiping
    • Structural Engineering and Mechanics
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    • v.69 no.2
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    • pp.205-219
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    • 2019
  • This paper analyzes nonlinear free vibration of the circular nano-tubes made of functionally graded materials in the framework of nonlocal strain gradient theory in conjunction with a refined higher order shear deformation beam model. The effective material properties of the tube related to the change of temperature are assumed to vary along the radius of tube based on the power law. The refined beam model is introduced which not only contains transverse shear deformation but also satisfies the stress boundary conditions where shear stress cancels each other out on the inner and outer surfaces. Moreover, it can degenerate the Euler beam model, the Timoshenko beam model and the Reddy beam model. By incorporating this model with Hamilton's principle, the nonlinear vibration equations are established. The equations, including a material length scale parameter as well as a nonlocal parameter, can describe the size-dependent in linear and nonlinear vibration of FGM nanotubes. Analytical solution is obtained by using a two-steps perturbation method. Several comparisons are performed to validate the present analysis. Eventually, the effects of various physical parameters on nonlinear and linear natural frequencies of FGM nanotubes are analyzed, such as inner radius, temperature, nonlocal parameter, strain gradient parameter, scale parameter ratio, slenderness ratio, volume indexes, different beam models.

Isolation of a Variant Strain of Pleurotus eryngii and the Development of Specific DNA Markers to Identify the Variant Strain

  • Lee, Hyun-Jun;Kim, Sang-Woo;Ryu, Jae-San;Lee, Chang-Yun;Ro, Hyeon-Su
    • Mycobiology
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    • v.42 no.1
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    • pp.46-51
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    • 2014
  • A degenerated strain of Pleurotus eryngii KNR2312 was isolated from a commercial farm. Random amplified polymorphic DNA analysis performed on the genomic DNA of the normal and degenerated strains of this species revealed differences in the DNA banding pattern. A unique DNA fragment (1.7 kbp), which appeared only in the degenerated strain, was isolated and sequenced. Comparing this sequence with the KNR2312 genomic sequence showed that the sequence of the degenerated strain comprised three DNA regions that originated from nine distinct scaffolds of the genomic sequence, suggesting that chromosome-level changes had occurred in the degenerated strain. Using the unique sequence, three sets of PCR primers were designed that targeted the full length, the 5' half, and the 3' half of the DNA. The primer sets P2-1 and P2-2 yielded 1.76 and 0.97 kbp PCR products, respectively, only in the case of the degenerated strain, whereas P2-3 generated a 0.8 kbp product in both the normal and the degenerated strains because its target region was intact in the normal strain as well. In the case of the P2-1 and P2-2 sets, the priming regions of the forward and reverse primers were located at distinct genomic scaffolds in the normal strain. These two primer sets specifically detected the degenerate strain of KNR2312 isolated from various mushrooms including 10 different strains of P. eryngii, four strains of P. ostreatus, and 11 other wild mushrooms.

Design, Optimization and Validation of Genomic DNA Microarrays for Examining the Clostridium acetobutylicum Transcriptome

  • Alsaker, Keith V.;Paredes, Carlos J.;Papoutsakis, Eleftherios T.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.5
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    • pp.432-443
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    • 2005
  • Microarray technology has contributed Significantly to the understanding of bacterial genetics and transcriptional regulation. One neglected aspect of this technology has been optimization of microarray-generated signals and quality of generated information. Full genome microarrays were developed for Clostridium acetobutylicum through spotting of PCR products that were designed with minimal homology with all other genes within the genome. Using statistical analyses it is demonstrated that Signal quality is significantly improved by increasing the hybridization volume. possibly increasing the effective number of transcripts available to bind to a given spot, while changes in labeled probe amounts were found to be less sensitive to improving signal quality. In addition to Q-RT-PCR, array validation was tested by examining the transcriptional program of a mutant (M5) strain lacking the pSOL1 178-gene megaplasmid relative to the wildtype (WT) strain. Under optimal conditions, it is demonstrated that the fraction of false positive genes is 1% when considering differentially expressed genes and 7% when considering all genes with signal above background. To enhance genomic-scale understanding of organismal physiology, using data from these microarrays we estimated that $40{\sim}55%$ of the C. acetobutylicum genome is expressed at any time during batch culture, similar to estimates made for Bacillus subtilis.