• Title/Summary/Keyword: segregation

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Expression and cDNA Cloning of klp-12 Gene Encoding an Ortholog of the Chicken Chromokinesin, Mediating Chromosome Segregation in Caenorhabditis elegans

  • Ali, M. Yusuf;Khan, M.L.A.;Shakir, M.A.;Kobayashi, K. Fukami;Nishikawa, Ken;Siddiqui, Shahid S.
    • BMB Reports
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    • v.33 no.2
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    • pp.138-146
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    • 2000
  • In eukaryotes, chromosomes undergo a series of complex and coordinated movements during cell division. The kinesin motor proteins, such as the chicken Chromokinesin, are known to bind DNA and transport chromosomes on spindle microtubles. We previously cloned a family of retrograde C-terminus kinesins in Caenorhabditis elegans that mediate chromosomal movement during embryonic development. Here we report the cloning of a C. elegans klp-12 cDNA, encoding an ortholog of chicken Chromokinesin and mouse KIF4. The KLP-12 protein contains 1609 amino acid and harbors two leucine zipper motifs. The insitu RNA hybridization in embryonic stages shows that the klp-12 gene is expressed during the entire embryonic development. The RNA interference assay reveals that, similar to the role of Chromokinesin, klp-12 functions in chromosome segregation. These results support the notion that during mitosis both types, the anterograde N-terminus kinesins such as KLP-12 and the retrograde C-terminus kinesins, such as KLP-3, KLP-15, KLP-16, and KLP-17, may coordinate chromosome assembly at the metaphase plate and chromosomal segregation towards the spindle poles in C. elegans.

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Characteristics of Settling and Consolidation Behavior for Non-Plastic Dredged Soils (비소성 준설토의 침강-압밀 거동 특성)

  • Park, Yun-Gyun;Park, Byung-Soo;Jeong, Gil-Soo;Yoo, Nam-Jea
    • Journal of Industrial Technology
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    • v.24 no.A
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    • pp.251-261
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    • 2004
  • A series of column test with a silty marine soil mixed with Jumunjin Standard Sand were performed to investigate the characteristics of settling and consolidation of non-plastic dredged soils. Column tests were carried out by using the separable column to measure the grain size distribution of consolidated layer. Column tests were performed with changing the mixing ratio of Jumunjin Standard Sand to the silty marine soil, initial water content of slurry and initial height of slurry. Height of interface of slurry was monitored during tests and grain size distribution tests were carried out after finishing tests. Influencing factors on the particle segregation, eventually to the characteristics of settling and consolidation of non-plastic soil, were analyzed on the thesis of test results. As results of column tests, the mixing ratio of sand to the silty marine soil and the initial water content of slurry were known to affect the characteristics of settling and consolidation resulted in significant particle segregation of slurry. Initial height of slurry was found not to affect seriously to particle segregation.

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Fabrication of Aluminum Alloy Composites Reinforced with SiC whisker an $Al_2O_3-SiO_2$ Short Fiber by Squeeze Casting (용탕단조에 의한 $Al_2O_3-SiO_2$ 단섬유 및 SiC whisker강화 알루미늄 합금기 복합재료의 제조)

  • Hong, Sung-Kil;Yun, Jung-Yul;Choi, Jung-Chul
    • Journal of Korea Foundry Society
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    • v.17 no.1
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    • pp.28-35
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    • 1997
  • SiC whisker and $Al_2O_3-SiO_2$ short fiber reinforced AC8A, AC8B and AC8B(J) marix composites were fabricated by squeeze casting method. Preform deformation, change of reinforcement volumefraction and formation of macro-segregation in two composites were investigated by using micro Vickers hardness test, analysis of macro and micro structures with OM, SEM and EDAX. $Al_2O_3-SiO_2$ short fiber preform manufactured with 5% $SiO_2$ binder in this study was considerably deformed and cracked, nevertheless, the short fibers were distributed homogeneously in the composites. In SiC whisker reinforced composites, on the other hand, preform deforming and cracking were not occurred, however, macro segregation zone formed along the infiltration routes by interface reaction during infiltration of molten metal into the preform was observed at center-low area in the composites. The decrease of hardness in the macro segregation zone resulted from the depletion of Si and Mg atoms.

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The Relationship between Residential Distribution of Immigrants and Crime in South Korea

  • Park, Yoonhwan
    • Journal of Distribution Science
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    • v.16 no.7
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    • pp.47-56
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    • 2018
  • Purpose - This study aims to not only investigate spatial pattern of immigrants' residence and crime occurrences in South Korea, but shed light on how geographic distribution of immigrants and immigrant segregation affect crime rates. Research design, data, and methodology - Th unit of analysis is Si-Gun-Gu municipal level entities of South Korea. The crime data was obtained by Korea National Police Agency and two major types(violence and property) of crime were measured. Most demographic, social, and economic variables were derived from Korean Census Data in 2015. In order to examine spatial patterns of immigrants' distribution and crime rates in South Korea, the present study utilized GIS mapping technique and Exploratory Spatial Data Analysis(ESDA) tools. The causal linkage was investigated by a series of regression models using STATA. Results - Spatial inequality between urban metropolitan vs rural areas was visualized by mapping. Assuming large Moran's I value, spatial autocorrelation appeared to be quite strong. Several neighborhood characteristics such as residential stability and economic prosperity were found to be important factors leading to crime rate change. Residential distribution and segregation for immigrants were negatively significant in the regression models. Conclusions - Unlike the traditional arguments of social disorganization theory, immigrant segregation appeared to reduce violent crime rate and the high proportion of immigrants also turned out to be a crime prevention factor.

Effects of Sulfur Segregation on Tertiary Recrystallization Kinetics in Thin-gauged 3% Si-Fe Electrical Strip

  • Chai, K.H.;Na, J.G.;Heo, N.H.;Kim, J.C.;Lee, S.R.;Woo, J.S.
    • Journal of Magnetics
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    • v.4 no.1
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    • pp.5-9
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    • 1999
  • Effect of sulfur segregation on tertiary recrystallization and magnetic induction during final annealing was investigated in a 3% Si-Fe electrical strip containing 6 ppm(LS) and 15 ppm(HS) sulfur. During final annealing, Auger peak height of segregated sulfur on the surface of the strips reached a maximum, and then decreased to low level with increasing annealing time, which is attributed to sulfur segregation and evaporation. The magnetic induction of the thin-gauged 3% Si strip was inversely proportional to the Auger peak height of segregated sulfur on the surface. The overall profile for surface segregation of sulfur and B10 was observed, irrespective of sulfur content in Si-Fe strips, but the peaks of LS strips appeared earlier than those of HS strips. The grain growth rate of the LS strips during final annealing was faster than that of the HS strips, which may be attributed to the pinning effects of segregated sulfur. With increasing final annealing temperature, B10 value increased rapidly and the saturation level in B10 increased.

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Variation of Alloying Element Distribution and Microstructure due to Microsegregation in Ni-base Superalloy GTD 111 (니켈기 초내열 합금 GTD 111에서 편석에 의한 합금원소 분포 및 미세조직 변화)

  • Choi, Baig-Gyu;Kim, In-Soo;Do, Jeong-Hyeon;Jung, Joong-Eun;Jo, Chang-Yong
    • Journal of Korea Foundry Society
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    • v.35 no.6
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    • pp.170-177
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    • 2015
  • Segregation during solidification and homogenization during thermal exposure in GTD 111 were investigated. The microstructures of as-cast, standard heat-treated, and thermally exposed specimens were observed by SEM. A compositional analysis of each specimen was conducted by EDS. The dendrite core was enriched in W and Co, though lower levels of Ti and Ta were observed. An unexpected phase, in this case like the ${\eta}$ phase, was observed due to segregation near the ${\gamma}-{\gamma}^{\prime}$ eutectic in the standard heat-treated specimen. Segregation also induced microstructural evolution near the ${\gamma}-{\gamma}^{\prime}$ eutectic during the standard heat treatment. A quantitative analysis and microstructural observations showed that the thermal exposure at a high temperature enhanced the chemical homogeneity of the alloy.

Evaluation of Mixing Conditions for the Production of Optimized High Flowing Concrete

  • Kim, Sang-Chel
    • KCI Concrete Journal
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    • v.11 no.3
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    • pp.79-88
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    • 1999
  • Most difficulties of inducing high fluidity on the concrete mixing design with a strength range of 210 to 240kg/$\textrm{cm}^2$ result from the segregation of aggregates due to the shortage of cementitious binders. To solve the problem, this study concentrated on finding the optimized amount of binder material which does not affect the concrete strength and is also economical. Also there were studies on the use of intermediate sized aggregates to avoid the gap-grading between coarse and fine aggregates so that the material segregation in high flowing concrete was and minimalized the fluidity and penetration capacity of the reinforcing bars was enhanced. Throughout the parametric study with respect to water/binder ratio. superplasticizer. replaceable mineral admixture, the size of coarse aggregate and mixing methods, the effect of each constituent on the characteristics of high flowing concrete could be observed. As a result or partially using stone powder or an intermediate class of aggregate (max. diameter 13mm) . it was fund that the fluidity of concrete significantly increased without material segregation and any change of compressive strengths. It was also proved in this study that proper mixing time and speed are significant factors influence the performence of high flowing concrete.

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Importance of family segregation in the American College of Medical Genetics and Genomics and Association of Molecular Pathology guidelines: Case of a Korean family with autosomal dominant polycystic disease

  • Kwon, Won Kyung;Kim, Suhee;Jang, Ja-Hyun;Kim, Jong-Won
    • Journal of Genetic Medicine
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    • v.17 no.1
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    • pp.51-54
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    • 2020
  • Since the American College of Medical Genetics and Genomics and Association of Molecular Pathology published their guidelines in 2015, most interpretations of genetic tests have followed them. However, all variants have only limited evidence along 28 interpretation standards, especially de novo variants. When de novo variants, which are classified as variants of uncertain significance (VUS) due to lack of evidence, are detected, segregation in the affected family could provide an important key to clarifying the variants. Autosomal dominant polycystic kidney disease is the most common inherited kidney disorder with pathogenic variants in the PKD1 or PKD2 genes. We detected a novel in-frame deletion variant in the PKD1 gene, c.7575_7577del (p.(Cys2526del)), which was interpreted as a VUS. We analyzed this variant in a Korean family to decide for segregation. Here, we report the variant as a likely pathogenic variant based on the evidence of segregation in three affected relatives and two unaffected members.

Epitaxial Growth of Graphene by Surface Segregation and Chemical Vapor Deposition on Ru(0001) Studied with Scanning Tunneling Microscopy (주사형 탐침 현미경을 이용한 Ru(0001) 위 그래핀의 에피탁시얼 성장 조건에 대한 연구)

  • Jang, Won-Jun;Kahng, Se-Jong
    • Journal of the Korean Vacuum Society
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    • v.22 no.6
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    • pp.285-290
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    • 2013
  • Epitaxial graphene on metal substrates provides excellent platforms to study its atomic and electronic structures, and can be grown either by surface segregation of carbon or by chemical vapor deposition. The growth behaviors of the two methods, however, have not been directly compared each other. Here, we studied domain structures of graphene grown by three different methods, surface segregation, post-annealing with adsorbed ethylene, and high-temperature dose of ethylene, using scanning tunneling microscopy. The first two methods resulted in graphene regions with areas of $100nm^2$, whereas the third method showed large area graphene (> $10^4nm^2$) with regular hexagonal Moire patterns, implying that high-temperature dose of ethylene is preferable for further studies on graphene such as additional growth of organic molecules.

Centerline Segregation of Pipe Plate made of API 5L X65 Steel (배관 강재 API 5L X65의 중심편석)

  • Choe, Byung Hak;Lee, Sang Woo;Kim, Woo Sik;Kim, Cheol Man
    • Journal of the Korean Institute of Gas
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    • v.24 no.5
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    • pp.39-46
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    • 2020
  • This paper is considered about centerline segregation of API 5L steel used in pipeline. Mn/S, Nb and C were known as segregated elements in the centerline of pipe thickness. The Mn usually was accompanied by S consisting of long viscous shape. Microstructure of the centerline was composed of MnS and Nb/Ti indusions including oxide. The segregation effect in centerline region was analyzed by OM, SEM/EDS and micro Vickers hardness. The Mn, Nb and C are retarded elements in transformation from austenite to ferrite or martensite. These elements could derive a bainitic microstructure as a kind of martensite, which is different from difference and element segregation between in matrix and centerline derived from steel melting and heat treatment.