• BMB Reports
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• 제52권10호
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• pp.607-612
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• 2019

During meiosis, programmed double-strand breaks (DSBs) are repaired via recombination pathways that are required for faithful chromosomal segregation and genetic diversity. In meiotic progression, the non-homologous end joining (NHEJ) pathway is suppressed and instead meiotic recombination initiated by nucleolytic resection of DSB ends is the major pathway employed. This requires diverse recombinase proteins and regulatory factors involved in the formation of crossovers (COs) and non-crossovers (NCOs). In mitosis, spontaneous DSBs occurring at the G1 phase are predominantly repaired via NHEJ, mediating the joining of DNA ends. The Ku complex binds to these DSB ends, inhibiting additional DSB resection and mediating end joining with Dnl4, Lif1, and Nej1, which join the Ku complex and DSB ends. Here, we report the role of the Ku complex in DSB repair using a physical analysis of recombination in Saccharomyces cerevisiae during meiosis. We found that the Ku complex is not essential for meiotic progression, DSB formation, joint molecule formation, or CO/NCO formation during normal meiosis. Surprisingly, in the absence of the Ku complex and functional Mre11-Rad50-Xrs2 (MRX) complex, a large portion of meiotic DSBs was repaired via the recombination pathway to form COs and NCOs. Our data suggested that Ku complex prevents meiotic recombination in the elimination of MRX activity.

• Journal of Ceramic Processing Research
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• 제19권6호
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• pp.509-513
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• 2018

This study uses fly ash for non-shrinkage grout in order to develop strength of grout and improve its durability. We grind fly ash to the extent of $7,000cm^2/g$ and use ground fly ash and raw fly ash respectively at the proportion of 10%, 20%, 30% instead of OPC and compare the results drawn on the condition of each proportion. As a mixed material of grout, EVA and water-reducing agent is added in order to prevent bleeding and improve segregation resistance, CSA is added with a view to preventing drying shrinkage and improving early strength property. In regard to flow and flow time test for analyzing and evaluating workability, it is revealed that grouts of all mix proportions except raw fly ash 30% mix proportion satisfy all performance criteria. With regard to length change rate, grout with no admixture shows the highest shrinkage rate, but the rate is 0.0005%, extremely insignificant rate. As material age increases, compressive strength of two grouts, that is to say ground fly ash 10% and 20%-used grouts, exceed that of grout with no admixture or show high-level compressive strength.

• 한국지반환경공학회 논문집
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• 제15권4호
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• pp.13-27
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• 2014

Catchments soil erosion, one of the most serious problems in the mountainous environment of the world, consists of a complex phenomenon involving the detachment of individual soil particles from the soil mass and their transport, storage and overland flow of rainfall, and infiltration. Sediment size distribution during erosion processes appear to depend on many factors such as rainfall characteristics, vegetation cover, hydraulic flow, soil properties and slope. This study involved laboratory flume experiments carried out under simulated rainfall in a 3.0 m long ${\times}$ 0.8 m wide ${\times}$ 0.7 m deep flume, set at $17^{\circ}$ slope. Five experimental cases, consisting of twelve experiments using three different sediments with two different rainfall conditions, are reported. The experiments consisted of detailed observations of particle size distribution of the out-flow sediment. Sediment water mixture out-flow hydrograph and sediment mass out-flow rate over time, moisture profiles at different points within the soil domain, and seepage outflow were also reported. Moisture profiles, seepage outflow, and movement of overland flow were clearly found to be controlled by water retention function and hydraulic function of the soil. The difference of grain size distribution of original soil bed and the out-flow sediment was found to be insignificant in the cases of uniform sediment used experiments. However, in the cases of non-uniform sediment used experiments the outflow sediment was found to be coarser than the original soil domain. The results indicated that the sediment transport mechanism is the combination of particle segregation, suspension/saltation and rolling along the travel distance.

• Molecules and Cells
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• 제21권3호
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• pp.360-366
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• 2006

Up to 35% of the rice genome consists of various kinds of transposons, and CACTA and MITE are two of the major class 2 DNA transposons in the genome. We have employed the consensus sequences of Rim2/Hipa CACTA, Stowaway MITE Pangrangja, and Tourist MITE Ditto for transposon display (TD) analysis to locate them on a genetic map, with 58 SSR markers used to anchor them. The TD analysis produced a high profile of the polymorphisms between the parental lines, Oryza sativa var. Gihobyeo/O. sativa var. Milyang, in intraspecific $F_{15}$ RIL lines, locating 368 markers of Rim2/Hipa CACTA, 78 markers of Tourist MITE Ditto, and 22 markers of Stowaway MITE Pangrangja. In the segregation analysis, non-parental segregating bands and segregation distortion bands were observed. The recombinant genetic map spans 3023.9 cM, with 5.7 cM the average distance between markers. The TD markers were distributed unequally on the chromosomes because many TD markers were located in pericentric chromosomal regions except in the cases of chromosomes 2, 3, 6 and 9. Although the number of transposon markers was not sufficient to include all rice class 2 transposons, the current map of CACTA and MITE transposons should provide new insight into the genome organization of rice since no previous DNA transposon map is available.

• 한국작물학회지
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• 제25권2호
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• pp.15-22
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• 1980

미립 Alkali 붕괴도의 변이성과 유전현상을 구명하기 위하여 Japonita와 Indica 품종에서 Alkali 붕괴도가 높고 낮온 8개 품종을 가지고 KOH 농도에 따른 변이와 재배시기 및 등숙온도에 따른 변이정도를 조사하고 이 결과에 따라 품종간 반응의 차이가 가장 큰 조건하에서 $F_2$를 재배하였을 때 28개 조합의 Alkali 붕괴도에 따른 개체별 분포상태를 조사하였다. 1. 미립 Alkali 붕괴도는 품종에 따라, KOH 농도에 따라 변이가 컸는데 그중 3$0^{\circ}C$ 에서 23시간 처리한 경우 1.4%에서 품종간 차이가 가장 컸다. 2. Alkali 붕괴도는 이앙기가 늦어짐에 따라, 등숙숙온도가 낮아짐에 따라 증가하였고 그 증가정도는 양처리에서 모두 낮은 품종군에서 더 컸다. 3. 낮은 품종군과 높은 품종군간의 붕괴도 차이가 가장 큰 조건은 조기재배와 주야간 30/22$^{\circ}C$ 의 등숙온도에서였다. 4. Alkali 붕괴도가 같은 군끼리의 교잡에서는 문배친에 가까운 분포를 나타내었고, 15개 조합의 낮은 품종과 높은 품종간의 교잡에서는 낮은 쪽이 우성인 3 : 1의 분리가 9조합이었고 9 : 7과 13:3이 각각 2조합, 1:3이 1조합 그리고 분리비에 맞지 않는 것이 1조합 이었다.

• Journal of Preventive Medicine and Public Health
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• 제56권1호
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• pp.31-40
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• 2023

Objectives: This study investigated the effect of cognitive impairment on the association between social network properties and mortality among older Korean adults. Methods: This study used data from the Korean Social Life, Health, and Aging Project. It obtained 814 older adults' complete network maps across an entire village in 2011-2012. Participants' deaths until December 31, 2020 were confirmed by cause-of-death statistics. A Cox proportional hazards model was used to assess the risks of poor social network properties (low degree centrality, perceived loneliness, social non-participation, group-level segregation, and lack of support) on mortality according to cognitive impairment. Results: In total, 675 participants (5510.4 person-years) were analyzed, excluding those with missing data and those whose deaths could not be verified. Along with cognitive impairment, all social network properties except loneliness were independently associated with mortality. When stratified by cognitive function, some variables indicating poor social relations had higher risks among older adults with cognitive impairment, with adjusted hazard ratios (HRs) of 2.12 (95% confidence interval [CI], 1.34 to 3.35) for social nonparticipation, 1.58 (95% CI, 0.94 to 2.65) for group-level segregation, and 3.44 (95% CI, 1.55 to 7.60) for lack of support. On the contrary, these effects were not observed among those with normal cognition, with adjusted HRs of 0.73 (95% CI, 0.31 to 1.71), 0.96 (95% CI, 0.42 to 2.21), and 0.95 (95% CI, 0.23 to 3.96), respectively. Conclusions: The effect of social network properties was more critical among the elderly with cognitive impairment. Older adults with poor cognitive function are particularly encouraged to participate in social activities to reduce the risk of mortality.

• 대한기계학회논문집B
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• 제20권10호
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• pp.3361-3370
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• 1996

Micro-Macro approach is conducted for the mixture solidification to handle the closely linked phenomena of microscopic solute redistribution and macroscopic solidification behavior. For this purpose, present work combines the efficiency of mixture theory for macro part and the capability of microscopic analysis of two-phase model for micro part. The micro part of present study is verified by comparison with experiment of Al-4.9 mass% Cu alloy. The effect of back diffusion on the macroscopic variables such as temperature and liquid concentration, is appreciable. The effect, however, is considerable on the mixture concentration and eutectic fraction which are indices of macro and micro segregation, respectively. According to the diffusion time, the behavior near the cooling wall where relatively rapid solidification permits short solutal diffusion time, approaches Scheil equation limit and inner part approaches lever rule limit.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권4호
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• pp.237-246
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• 2004

The advantages of the Magnetic Fluid Linear Pump(MFLP) is that this device could Pump the non-conductive. non-magnetic liquid such as Insulin or blood because of the segregation structure of the magnetic fluid and pumping liquid. In this device. the sequential currents are needed to Produce pumping forces so that Pumping Forces and Pumping speed mainly depend on the current Patterns. The excessive forces at Pumping moment could cause the medical shock, and weak forces at intermediate moment could cause the back flow or the pumping liquid. So the ripples of the pumping forces need to be reduced for the medical application. In this research, the driving characteristics in the MFLP by operating current is analysed. The change of magnetic fluid surface according to the driving currents could be obtained be magneto-hydrodynamic analysis so that Pumping fortes could be computed by integration of the surface moving to the pumping direction at each moment. The actual MFLP with 13mm diameter was made and tested for experiments. The effects of driving current and frequency on the pumping forces and pumping speed were analyzed and compared with experimental measurements.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.269-274
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• 1998

In this study, to increase fluidity and resistance of segregation of materials, the effect of each of the materials, which have effects on high performance concrete from investigating the properties of strength and drying shrinkage of high performance concrete made by the basic mix proportion used fly-ash and ground granulated blast-furnace slag after hardening, has been checked. According to the experimental results, fluidity on W/C = 34% was satisfied within slump-flow 65$\pm$ 5cm and U-type self-compactability difference 5cm. On the properties of strength, high performance concrete produced compressive strength over 400kg/$\textrm{cm}^2$ in 28days when powder was replaced by 40% of fly-ash and 60% of ground granulated blast-furnace slag. And compressive strength was taken over 600kg/$\textrm{cm}^2$ equal to non-replacement in 91days. Also, the length change of concrete with the addition of fly-ash was smaller than that without it. Therefore, it may be effective on the decrease of drying shrinkage volume.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.275-280
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• 1998

In this study, to increase fluidity and resistance of segregation of materials, the effect of each of the materials, which have effects on high performance concrete from investigating the properties of strength and drying shrinkage of high performance concrete made by the basic mix proportion used fly-ash and ground granulated blast-furnace slag after hardening, has been checked. By the results of this experiment, fluidity on W/C=34% was satisfied within slump-flow 65$\pm$5cm and U-type self-compacting difference 5cm. On the properties of strength, high performance concrete produced compressive strength over 400kg/$\textrm{cm}^2$ in 28days when powder was replaced by 40% of fly-ash and 60% of ground granulated blast-furnace slag. And compressive strength was taken over 600kg/$\textrm{cm}^2$ equal to non-replacement in 91days. Also, the length change of concrete with the addition of fly-ash was smaller than that without it. Therefore, it may be effective on the decrease of drying shrinkage volume.