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Search Results: 1 - 10 of 33347 matches for " Jung-Hyun Lee2 "
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Preferred Feeding Sites and Prey of the Adult Gold-spotted Pond Frog, Rana plancyi chosenica
Eom, Junho1,Jung-Hyun Lee2,Nam-Yong Ra2,Daesik Park1*
Journal of Ecology and Field Biology , 2007,
Abstract: To determine the feeding sites preferred by adult gold-spotted pond frogs, Rana plancyi chosenica,and the foods that induce favorable growth of the frogs in the laboratory, we conducted two separate experimentsbetween 27 May and 12 July 2007 in a vivarium. In the first experiment, we counted the number of cricketseaten by four gold-spotted pond frogs in a 60 min period at four different feeding sites within the experimentalarenas: on the water surface, at the edge of a pond, and at two terrestrial sites. Adult gold-spotted pond frogsate more crickets on the water surface and at the edge of the pond than the terrestrial sites. In the secondexperiment, we measured the growth of SVL (snout-vent length) and body mass of adult gold-spotted pond frogsfed crickets, mealworms, maggots, or earthworms in individual experimental boxes over a one month period. TheSVL and body mass of the adult gold-spotted pond frogs fed crickets, mealworms, or maggots were greater thanthose of the frogs that were fed earthworms. These results indicate that providing crickets, mealworms, ormaggots on the water or at the edge of a pond should induce favorable growth of captive-reared adult goldspottedpond frogs.
Single Nucleotide Polymorphisms and Haplotypes in Vascular Endothelial Growth Factor Gene and Residual Ridge Resorption of Mandible in Korean Population  [PDF]
Jung-Hyun Song, Jae-Hoon Lee
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2014, DOI: 10.4236/jbnb.2014.51006
Abstract:

The tooth extraction is a routine surgical procedure in the dental treatment where the healing process results in a saddle-shaped residual ridge in the edentulous jaw. There are substantial differences among individuals in the end result. In some cases, there is excessive bone atrophy, which complicates the dental restorative treatment. The alveolar ridge receives the mechanical load continuously from the periodontal ligament connected to the teeth and it diminishes dramatically as a consequence of dental extraction; thus it is believed the continuing pattern of the alveolar bone resorption is related to this change. The reduced partial pressure of oxygen is the most prominent event from the reduced mechanical load. Vascular Endothelial Growth Factor (VEGF), regulated by HIF-1, reported close association with angiogenesis and bone turn over, where partial oxygen pressure has changed. Therefore the genetic association between Single Nucleotide Polymorphsim (SNP) of VEGF gene and RRR was investigated. 120 subjects (70.93 ± 9.28 years) which were treated at Dental clinic of Yonsei University with edentulous mandible were recruited. Mandibular bone height was measured following the protocol of the American College of Prosthodontists. Three variants, rs1570360, rs25648, and rs3025039 in VEGF from previous study, were used as tag-SNPs and genotyping for the study. Student’s t-test and ANOVA were used for statistical analysis. There was a notable association with rs1570360 (

Effects of Physical Parameters and Age on the Order of Entrance of Hynobius leechii to a Breeding Pond
Lee, Jung-Hyun,Daesik Park
Journal of Ecology and Field Biology , 2008,
Abstract: To determine the age structure of a Hynobius leechii breeding population and analyze relationshipsbetween the order of entrance to breeding ponds and physical parameters and age, we studied a wild populationof the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Koreafrom March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of femalesranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm,respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-ventlength (SVL), head length, and body mass of males were all positively correlated with their age, but female agedid not show a significant relationship with any physical parameter. The tail depth, body mass, and conditionfactors (SVL/body mass × 100) of both males and females were negatively related with the order of entranceto the breeding pond. The head width and SVL of males were also negatively correlated with the order ofentrance, but the SVL of females was positively related with the order of entrance. These results suggest thatphysical parameters are more important determinants of breeding migration patterns than age. We discuss whichof two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explainthe order of entrance to breeding ponds for male and female H. leechii.
Link-Disjoint Broadcasting Algorithm in Wormhole-Routed 3D Petersen-Torus Networks
Jung-hyun Seo,HyeongOk Lee
International Journal of Distributed Sensor Networks , 2013, DOI: 10.1155/2013/501974
Abstract: In a network, one-to-all broadcasting is the process of disseminating messages from a source node to all the nodes existing in the network through successive data transmissions between pairs of nodes. Broadcasting is the most primary communication process in a network. A 3D Petersen-Torus (3D PT) network has been proposed recently. the three-dimensionally magnified Petersen-Torus topology, 3D PT, is suitable for establishing a wireless sensor network (WSN) in 3D rectangular or cylindrical structures such as buildings. We propose a link-disjoint broadcasting algorithm for half-duplex 3D PT networks with wormhole routing and prove that the broadcasting algorithm is link-disjoint and the broadcasting step is in 3D PT . 1. Introduction In wireless sensor network (WSN), after sensor nodes are deployed, they self-organize and establish routes automatically and transmit their information on their surroundings to a base station (BS). Since each sensor node has a limited and irreplaceable energy resource, energy conservation is the most important performance consideration in a WSN [1]. To decrease the energy consumption of a node, it is very important to effectively transmit collected data to a router through a sink node. For effective message transmission, a routing path should be short, without message congestion. When the routing path is long, the number of nodes used for message transmission increases, leading to additional energy consumption. Further, link congestion results in excessive energy consumption and lower transfer rate. A routing protocol influenced by node topology is crucial to reducing energy consumption. Topologies used for effective routing include star [2], peer-to-peer (P2P) [3], grid mesh [4], and hexagonal honeycomb [5]. The Petersen-Torus, a topology that connects a Petersen graph in the grid shape, involves lower network costs than both the grid mesh and the honeycomb. 3D PT, the three-dimensionally magnified Petersen-Torus topology, is suitable for establishing a wireless sensor network (WSN) in 3D rectangular or cylindrical structures such as buildings. 3D PT involves lower network costs than the 3D mesh or the 3D honeycomb [6]. This study proposes broadcasting for data transmission in a WSN topology using 3D PT. As the proposed broadcasting is edge-disjoint, it does not cause message congestion. The time complexity, which is at 3D PT , is confirmed to be efficient. It is anticipated that sequential computers will reach their physical limitations in terms of CPU speed and memory size. Over the past years, high performance computing
Trend of Nitriding on Chromium-Molybdenum Steel via Low Temperature Screen Plasma Technology  [PDF]
Kuk-Hyun Yeo, Sang-Gweon Kim, Jae-Hoon Lee, Jung-Hyun Kong, Masahiro Okumiya
Advances in Materials Physics and Chemistry (AMPC) , 2014, DOI: 10.4236/ampc.2014.48017
Abstract: Low temperature screen plasma technology, a high plasma density, through using a low energy supply, shows excellent effects on a low alloy chromium-molybdenum steel for plastic molds because it does not show a compound layer and a high surface hardness without a deterioration in matrix hardness. For interest about hardening depth, both the screen plasma nitriding and plasma nitro-carburizing processes were tested including nitrogen, hydrogen and a methane mixed gas environmental at 653 K, 713 K. The optical emission spectroscopy (OES) has been analyzed during screen plasma nitriding (SPN) and a nitro-carburizing process (SPNC) was proceeded at 713 K and the same pressure. I find it difficult to dissociate nitrogen molecules perfectly with neutral nitrogen atoms via the DC-plasma nitriding process. Therefore, the SPN and SPNC process have shown a high density of plasma species even though low temperature plasma conditions have a high peak intensity of Hβ and Hγ in the results of the analysis by OES. The hardness value was measured with the micro-Vickers hardness tester after the SPN, SPNC process and the chemical composition of nitriding layers were traced by GDOES. The screen nitriding layer via the screen plasma technology has shown excellent properties with a thickness depth of about 850 ~ 900 HV without the deterioration of matrix hardness value.
Influence of Driver’s Career and Secondary Cognitive Task on Visual Search Behavior in Driving: A Dual-Task Paradigm  [PDF]
Hye-In Lee, Seungha Park, Jongil Lim, Seung Ho Chang, Jung-Hyun Ji, Seungmin Lee, Jihye Lee
Advances in Physical Education (APE) , 2015, DOI: 10.4236/ape.2015.54029
Abstract: The purpose of this study was to investigate the effect of driving career and secondary cognitive task on dual-tasking performances and visual search behavior. Twenty male participants were grouped in the following two groups: the experienced group and the novice group. All participants were asked to drive at a speed of 120 km/h while keeping to a lane on the highway and engaging with the following three levels of secondary cognitive task: no cognitive task, easy level, and hard level. The results showed significantly lower correct response rates in the dual task condition (driving + cognitive task) than in the driving only task condition. Novice drivers showed greater decrements in cognitive task performance, particularly in the dual task condition, as compared to the experienced drivers. The total fixation duration decreased as the level of the secondary task increased in difficulty. Experienced drivers showed significantly longer fixation duration on the far-area of the road, and also on specific areas, whereas novice drivers fixated longer on the near-area of the road. In conclusion, we suggest that the importance of perceptual skills in driving should be emphasized and effective training methods need to be applied, especially among high-risk drivers.
Five-year monitoring of herpetofauna in Woraksan National Park
Jung-Hyun Lee,Nam-Yong Ra,Daesik Park
Journal of Ecology and Field Biology , 2011,
Abstract: In this study, in order to determine how climate change may affect amphibian and reptile communities, we surveyedthe numbers of egg clumps and adults of amphibians and the number of reptiles at eight amphibian and nine reptilesurvey sites in Woraksan National Park from March 2005 to September 2009. We assessed the relationships among sixclimate factors (annual minimum temperature, annual maximum temperature, monthly mean temperature, monthlymean precipitation, monthly mean temperature during winter, and monthly mean precipitation during winter); speciesdiversity, evenness, and richness indexes for both amphibians and reptiles; and the number of each species and eggclumps of three amphibian species. First, both the amphibian and reptile species indices evidenced sudden changes in2007, when climate factors in Korea fluctuated substantially. Second, amphibian diversity and evenness were negativelyrelated with annual minimum temperature. Increased monthly mean precipitation had a positive effect in mountainedge sites, but a negative effect in valley sites. Third, reptile species evenness was positively related with monthly meanprecipitation. In particular, the monthly mean temperature in the winter season affected the numbers of the Dione's ratsnake and the Korean tiger keelback snake. These results indicate that amphibian and reptile communities are respondingto climate change in a variety of ways.
Natural diterpenes from coffee, cafestol and kahweol induce apoptosis through regulation of specificity protein 1 expression in human malignant pleural mesothelioma
Kyung-Ae Lee, Jung-Il Chae, Jung-Hyun Shim
Journal of Biomedical Science , 2012, DOI: 10.1186/1423-0127-19-60
Abstract: Cells were treated separately with final concentration of cafestol and kahweol and the results were analyzed by MTS assay, DAPI staining, PI staining, luciferase assay, RT-PCR, and immunoblotting.Viability of MSTO-211H and H28 cells were decreased, and apoptotic cell death was increased in MSTO-211H as a result of cafestol and kahweol treatment. Cafestol and kahweol increased Sub-G1 population and nuclear condensation in MSTO-211H cells. Roles of Sp1 in cell proliferation and apoptosis of the MSTO-211H cells by the Sp1 inhibitor of Mithramycin A were previously confirmed. Cafestol and kahweol significantly suppressed Sp1 protein levels. Kahweol slightly attenuated Sp1 mRNA, while Cafestol did not affect in MSTO-211H cells. Cafestol and kahweol modulated the promoter activity and protein expression level of the Sp1 regulatory genes including Cyclin D1, Mcl-1, and Survivin in mesothelioma cells. Apoptosis signaling cascade was activated by cleavages of Bid, Caspase-3, and PARP with cafestol and by upregulation of Bax, and downregulation of Bcl-xl by kahweol.Sp1 can be a novel molecular target of cafestol and kahweol in human MPM.
Herpetofauna and habitat characteristics of 16 lagoons along the eastern coastline of South Korea
Jung-Hyun Lee,Daesik Park,Heon-Joo Lee,Ja-Kyeong Kim
Journal of Ecology and Field Biology , 2010,
Abstract: We conducted field surveys of amphibians and reptiles over a two-year period in 16 lagoons along the eastern coastlineof South Korea, and determined the habitat characteristics correlated with the number of amphibian and reptilianspecies and individuals. We documented 11 amphibian species and 8 reptilian species. The dominant amphibian specieswas the black-spotted pond frog (Rana nigromaculata), and the dominant reptilian species was the red-eared turtle(Trachemys scripta elegans), an invasive species. Among the 14 habitat characteristics, connectivity to mountainous areasignificantly affected the number of amphibian and reptilian individuals. Other factors, including emerged plant cover,salinity, pH, the number of birds for amphibians and connectivity to agricultural land, lagoon perimeter length for reptilesalso influenced the number of species or individuals of them. Our results demonstrate that these lagoons are hometo more amphibians and reptiles than has been previously known. To effectively conserve herpetofauna in the lagoonecosystem, lagoons as well as surrounding wetlands, grasslands, and mountainous areas should be protected.
Ectoparasites: immature Japanese hard ticks (Ixodes nipponensis; Acari: Ixodidae) on Korean lizards
Nam-Yong Ra,Jun-Ki Lee,Jung-Hyun Lee,Ja-Kyeong Kim
Journal of Ecology and Field Biology , 2011,
Abstract: Although lizards are important hosts for hard ticks (Ixodidae), very few studies have been conducted in South Korea. Todetermine whether or not hard ticks can infest lizards endemic to South Korea, we examined 77 lizards of four species(Eremias argus, Sincella vandenburghi, Takydromus amurensis, and Takydromus wolteri) that were collected at 22 differentsites between April and October 2010. We confirmed that all four lizard species can be infested by Ixodes nipponensislarvae or nymphs. Of the 62 E. argus examined, we found an average of 12.5 larvae on two lizards and an averageof one nymph on one lizard. We found seven nymphs on one S. vandenburghi. We found an average of two nymphs ontwo of the five T. amurensis and an average of one nymph on four of the nine T. wolteri. Ixodes nipponensis larvae andnymphs were found most frequently on the foreleg axillae (87.8%), followed by the forelegs (7.3%), the eyelids (2.4%),and the ears (2.4%) of the lizards. To the best of our knowledge, this is the first report of I. nipponensis infestations oflizards endemic to South Korea.
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