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Search Results: 1 - 10 of 9224 matches for " Eung-Woo Park "
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An accurate method for quantifying and analyzing copy number variation in porcine KIT by an oligonucleotide ligation assay
Bo-Young Seo, Eung-Woo Park, Sung-Jin Ahn, Sang-Ho Lee, Jae-Hwan Kim, Hyun-Tae Im, Jun-Heon Lee, In-Cheol Cho, Il-Keun Kong, Jin-Tae Jeon
BMC Genetics , 2007, DOI: 10.1186/1471-2156-8-81
Abstract: PCR followed by a quantitative oligonucleotide ligation assay (qOLA) was developed for quantifying CNVs. The accuracy and precision of the assay were evaluated for porcine KIT, which was selected as a model locus. Overall, the root mean squares of bias and standard deviation of qOLA were 2.09 and 0.45, respectively. These values are less than half of those in the published pyrosequencing assay for analyzing CNV in porcine KIT. Using a combined method of qOLA and another pyrosequencing for quantitative analysis of KIT copies with spliced forms, we confirmed the segregation of KIT alleles in 145 F1 animals with pedigree information and verified the correct assignment of genotypes. In a diagnostic test on 100 randomly sampled commercial pigs, there was perfect agreement between the genotypes obtained by grouping observations on a scatter plot and by clustering using the nearest centroid sorting method implemented in PROC FASTCLUS of the SAS package. In a test on 159 Large White pigs, there were only two discrepancies between genotypes assigned by the two clustering methods (98.7% agreement), confirming that the quantitative ligation assay established here makes genotyping possible through the accurate measurement of high KIT copy numbers (>4 per diploid genome). Moreover, the assay is sensitive enough for use on DNA from hair follicles, indicating that DNA from various sources could be used.We have established a high resolution quantification method using an oligonucleotide ligation assay to measure CNVs, and verified the reliability of genotype assignment for random animal samples using the nearest centroid sorting method. This new method will make it more practical to determine KIT CNV and to genotype the complicated Dominant White/KIT locus in pigs. This procedure could have wide applications for studying gene or segment CNVs in other species.Susceptibility to genetic disorders is known to be associated not only with single nucleotide polymorphisms (SNP), but also w
Use of a bovine genome array to identify new biological pathways for beef marbling in Hanwoo (Korean Cattle)
Seung-Hwan Lee, Cedric Gondro, Julius van der Werf, Nam-Kuk Kim, Da-jeong Lim, Eung-Woo Park, Sung-Jong Oh, John P Gibson, John M Thompson
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-623
Abstract: Bovine genome array analysis was conducted to detect differentially expressed genes (DEGs) in m. longissimus with divergent marbling phenotype (marbling score 2 to 7). Three data-processing methods (MAS5.0, GCRMA and RMA) were used to test for differential expression (DE). Statistical analysis identified 21 significant transcripts from at least two data-processing methods (P < 0.01). All 21 differentially expressed genes were validated by real-time PCR. Results showed a high concordance in the gene expression fold change between the microarrays and the real time PCR data. Gene Ontology (GO) and pathway analysis demonstrated that some genes (ADAMTS4, CYP51A and SQLE) over expressed in high marbled animals are involved in a protein catabolic process and a cholesterol biosynthesis process. In addition, pathway analysis also revealed that ADAMTS4 is activated by three regulators (IL-17A, TNFα and TGFβ1). QRT-PCR was used to investigate gene expression of these regulators in muscle with divergent intramuscular fat contents. The results demonstrate that ADAMTS4 and TGFβ1 are associated with increasing marbling fat. An ADAMTS4/TGFβ1 pathway seems to be associated with the phenotypic differences between high and low marbled groups.Marbling differences are possibly a function of complex signaling pathway interactions between muscle and fat. These results suggest that ADAMTS4, which is involved in connective tissue degradation, could play a role in an important biological pathway for building up marbling in cattle. Moreover, ADAMTS4 and TGFβ1could potentially be used as an early biological marker for marbling fat content in the early stages of growth.Intramuscular fat deposition in cattle starts to become visible at 12 months of age and the rate of deposition increases from 15 months to 24 months [1]. The initial formation of visible intramuscular fat seems to be driven through the development of adipocytes in combination with declining muscle growth [2]. It has been shown th
Neuronal Genes for Subcutaneous Fat Thickness in Human and Pig Are Identified by Local Genomic Sequencing and Combined SNP Association Study
Kyung-Tai Lee,Mi-Jeong Byun,Kyung-Soo Kang,Eung-Woo Park,Seung-Hwan Lee,Seoae Cho,HyoYoung Kim,Kyu-Won Kim,TaeHeon Lee,Jong-Eun Park,WonCheoul Park,DongHyun Shin,Hong-Seog Park,Jin-Tae Jeon,Bong-Hwan Choi,Gul-Won Jang,Sang-Haeng Choi,Dae-Won Kim,Dajeong Lim,Hae-Suk Park,Mi-Rim Park,Jurg Ott,Lawrence B. Schook,Tae-Hun Kim,Heebal Kim
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0016356
Abstract: Obesity represents a major global public health problem that increases the risk for cardiovascular or metabolic disease. The pigs represent an exceptional biomedical model related to energy metabolism and obesity in humans. To pinpoint causal genetic factors for a common form of obesity, we conducted local genomic de novo sequencing, 18.2 Mb, of a porcine QTL region affecting fatness traits, and carried out SNP association studies for backfat thickness and intramuscular fat content in pigs. In order to relate the association studies in pigs to human obesity, we performed a targeted genome wide association study for subcutaneous fat thickness in a cohort population of 8,842 Korean individuals. These combined association studies in human and pig revealed a significant SNP located in a gene family with sequence similarity 73, member A (FAM73A) associated with subscapular skin-fold thickness in humans (rs4121165, GC-corrected p-value = 0.0000175) and with backfat thickness in pigs (ASGA0029495, p-value = 0.000031). Our combined association studies also suggest that eight neuronal genes are responsible for subcutaneous fat thickness: NEGR1, SLC44A5, PDE4B, LPHN2, ELTD1, ST6GALNAC3, ST6GALNAC5, and TTLL7. These results provide strong support for a major involvement of the CNS in the genetic predisposition to a common form of obesity.
Epoxy-Carbazole Polymeric Network Nanolayers for Organic Light-Emitting Devices
Jin-Woo Park,Eung-Kyoo Lee,Myon Cheon Choi,Hwajeong Kim,Jihwan Keum,Chang-Sik Ha,Youngkyoo Kim
Journal of Nanomaterials , 2006, DOI: 10.1155/jnm/2006/46787
Abstract: We report the study of epoxy-carbazole polymeric network (ECzPN) nanolayers as a hole injection/transport layer in organic light-emitting devices. The ECzPN nanolayers were prepared by the thermal curing reaction of epoxidized cresol novolak and 3,6- diaminocarbazole in the presence of catalytic amount of triphenyl phosphine. The curing reaction was examined with Fourier transformed infrared spectroscopy, whilst the thermal stability was studied with thermogravimetric analysis. Optical absorption and emission spectroscopy were employed to investigate the optical properties of ECzPN nanolayers, whilst atomic force microscopy was used to examine the surface nanomorphology of ECzPN nanolayers. The result showed that the device performance was greatly influenced by the weight ratio of monomers, because the highest occupied molecular orbital level of ECzPN was significantly changed with the ratio. This is attributed to the ground-state complexes induced by the specific interaction (hydrogen bonding) between the lone pair electrons in amines of carbazole moieties and the hydroxyl group of ring-opened epoxide moieties.
Mammalian Ste20-Like Kinase and SAV1 Promote 3T3-L1 Adipocyte Differentiation by Activation of PPARγ
Byoung Hee Park, Dae Soon Kim, Gun Woo Won, Hyun Jeong Jeon, Byung-Chul Oh, YoungJoo Lee, Eung-Gook Kim, Yong Hee Lee
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030983
Abstract: The mammalian ste20 kinase (MST) signaling pathway plays an important role in the regulation of apoptosis and cell cycle control. We sought to understand the role of MST2 kinase and Salvador homolog 1 (SAV1), a scaffolding protein that functions in the MST pathway, in adipocyte differentiation. MST2 and MST1 stimulated the binding of SAV1 to peroxisome proliferator-activated receptor γ (PPARγ), a transcription factor that plays a key role in adipogenesis. The interaction of endogenous SAV1 and PPARγ was detected in differentiating 3T3-L1 adipocytes. This binding required the kinase activity of MST2 and was mediated by the WW domains of SAV1 and the PPYY motif of PPARγ. Overexpression of MST2 and SAV1 increased PPARγ levels by stabilizing the protein, and the knockdown of SAV1 resulted in a decrease of endogenous PPARγ protein in 3T3-L1 adipocytes. During the differentiation of 3T3-L1 cells into adipocytes, MST2 and SAV1 expression began to increase at 2 days when PPARγ expression also begins to increase. MST2 and SAV1 significantly increased PPARγ transactivation, and SAV1 was shown to be required for the activation of PPARγ by rosiglitazone. Finally, differentiation of 3T3-L1 cells was augmented by MST2 and SAV1 expression and inhibited by knockdown of MST1/2 or SAV1. These results suggest that PPARγ activation by the MST signaling pathway may be a novel regulatory mechanism of adipogenesis.
Precision improvement of MEMS gyros for indoor mobile robots with horizontal motion inspired by methods of TRIZ
Dongmyoung Shin,Sung Gil Park,Byung Soo Song,Eung Su Kim,Oleg Kupervasser,Denis Pivovartchuk,Ilya Gartseev,Oleg Antipov,Evgeniy Kruchenkov,Alexey Milovanov,Andrey Kochetov,Igor Sazonov,Igor Nogtev,Sun Woo Hyun
Computer Science , 2013,
Abstract: In the paper, the problem of precision improvement for the MEMS gyrosensors on indoor robots with horizontal motion is solved by methods of TRIZ ("the theory of inventive problem solving").
Dark matter and sub-GeV hidden U(1) in GMSB models
Chun, Eung Jin;Park, Jong-Chul
High Energy Physics - Phenomenology , 2008, DOI: 10.1088/1475-7516/2009/02/026
Abstract: Motivated by the recent PAMELA and ATIC data, one is led to a scenario with heavy vector-like dark matter in association with a hidden $U(1)_X$ sector below GeV scale. Realizing this idea in the context of gauge mediated supersymmetry breaking (GMSB), a heavy scalar component charged under $U(1)_X$ is found to be a good dark matter candidate which can be searched for direct scattering mediated by the Higgs boson and/or by the hidden gauge boson. The latter turns out to put a stringent bound on the kinetic mixing parameter between $U(1)_X$ and $U(1)_Y$: $\theta \lesssim 10^{-6}$. For the typical range of model parameters, we find that the decay rates of the ordinary lightest neutralino into hidden gauge boson/gaugino and photon/gravitino are comparable, and the former decay mode leaves displaced vertices of lepton pairs and missing energy with distinctive length scale larger than 20 cm for invariant lepton pair mass below 0.5 GeV. An unsatisfactory aspect of our model is that the Sommerfeld effect cannot raise the galactic dark matter annihilation by more than 60 times for the dark matter mass below TeV.
Black Photoresist for Patterning Pixel Define Layer of Organic Light Emitting Diode with Polyimide as Thermal Stabilizer  [PDF]
Genggongwo Shi, Jin Woo Park, Lee Soon Park
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.96040
Abstract: In order to improve the visibility for outside use of organic light emitting diodes (OLEDs), the polarized film and black matrix pattern have been used in the small and medium sized OLEDs; however, these cause problem of reducing the emission efficiency of OLED. Changing the color of pixel define layer (PDL) from brown to black is an important point for improving the efficiency and visibility of OLEDs. In this work we studied the photoresist material containing black pigment and the photolithographic process for patterning of black PDL on OLEDs. The black PDL patterns made with our synthesized polyimides as thermal stabilizer were found to give high thermal stability over 300°C.
An Iterative Method for Problems with Multiscale Conductivity
Hyea Hyun Kim,Atul S. Minhas,Eung Je Woo
Computational and Mathematical Methods in Medicine , 2012, DOI: 10.1155/2012/893040
Abstract: A model with its conductivity varying highly across a very thin layer will be considered. It is related to a stable phantom model, which is invented to generate a certain apparent conductivity inside a region surrounded by a thin cylinder with holes. The thin cylinder is an insulator and both inside and outside the thin cylinderare filled with the same saline. The injected current can enter only through the holes adopted to the thin cylinder. The model has a high contrast of conductivity discontinuity across the thin cylinder and the thickness of the layer and the size of holes are very small compared to the domain of the model problem. Numerical methods for such a model require a very fine mesh near the thin layer to resolve the conductivity discontinuity. In this work, an efficient numerical method for such a model problem is proposed by employing a uniform mesh, which need not resolve the conductivity discontinuity. The discrete problem is then solved by an iterative method, where the solution is improved by solving a simple discrete problem with a uniform conductivity. At each iteration, the right-hand side is updated by integrating the previous iterate over the thin cylinder. This process results in a certain smoothing effect on microscopic structures and our discrete model can provide a more practical tool for simulating the apparent conductivity. The convergence of the iterative method is analyzed regarding the contrast in the conductivity and the relative thickness of the layer. In numerical experiments, solutions of our method are compared to reference solutions obtained from COMSOL, where very fine meshes are used to resolve the conductivity discontinuity in the model. Errors of the voltage in L2 norm follow O(h) asymptotically and the current density matches quitewell those from the reference solution for a sufficiently small mesh size h. The experimental results present a promising feature of our approach for simulating the apparent conductivity related to changes in microscopic cellular structures. 1. Introduction Electrical conductivity of a material is a measure of its ability to allow the movement of electric charge. Based on the material’s atomic or molecular composition, electric charge may be either in the form of free electrons or ions. In a homogeneous saline solution, for example, there is ionic electric charge and its conductivity is determined by the total sum of the multiplication of concentration and the mobility of various ions presents in the solution [1]. The mobility of ions depends on the structural composition of the
Application of Design of Experiment Method for Thrust Force Minimization in Step-feed Micro Drilling
Dong-Woo Kim,Myeong-Woo Cho,Tae-il Seo,Eung-Sug Lee
Sensors , 2008, DOI: 10.3390/s8010211
Abstract: Micro drilled holes are utilized in many of today’s fabrication processes.Precision production processes in industries are trending toward the use of smaller holeswith higher aspect ratios, and higher speed operation for micro deep hole drilling. However,undesirable characteristics related to micro drilling such as small signal-to-noise ratios,wandering drill motion, high aspect ratio, and excessive cutting forces can be observedwhen cutting depth increases. In this study, the authors attempt to minimize the thrustforces in the step-feed micro drilling process by application of the DOE (Design ofExperiment) method. Taking into account the drilling thrust, three cutting parameters,feedrate, step-feed, and cutting speed, are optimized based on the DOE method. Forexperimental studies, an orthogonal array L27(313) is generated and ANOVA (Analysis ofVariance) is carried out. Based on the results it is determined that the sequence of factorsaffecting drilling thrusts corresponds to feedrate, step-feed, and spindle rpm. Acombination of optimal drilling conditions is also identified. In particular, it is found in thisstudy that the feedrate is the most important factor for micro drilling thrust minimization.
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