Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

Park, Chang-hyun,Chang, Won Hyuk,Yoo, Woo-Kyoung,Shin, Yong-Il,Kim, Sung Tae,Kim, Yun-Hee Mary Ann Liebert 2014 Brain connectivity Vol.4 No.4

<P>Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.</P>

Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

Cho, Yong-Chan,Lee, Chang-Seok,Cho, Hyun-Je,Lee, Kyu-Song,Park, Pil-Sun The Ecological Society of Korea 2011 Journal of Ecology and Environment Vol.34 No.1

Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.

Long second toe: its nail and skin changes

( Geun-hwi Park ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Tae-wook Kim ),( Sung-min Park ),( Hyun-joo Lee ),( Gun-wook Kim ),( Hoon-soo Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Nail can be affected by trauma, infection, and systematic disorders. In particular, the toe nails are exposed to the repeated and cumulative minor traumas, which usually result in thickened, splitted, and discolorated nails. Considering these, it can be inferred that the long second toe can be related to various nail and skin changes by repeated minor traumas such as friction in shoes, but the study or report on this topic hasn’t been done yet. Objectives: The purpose of this study was to introduce various nail and skin changes on long second toe. Methods: We analyzed the kinds of nail/skin changes of 50 patients with long second toe, enrolled at Pusan National University Hospitals (Busan and Yangsan) from 2013 to 2018. Results: There was no significant difference in the incidence of left and right toe and toenail, and 7 (14%) patients presented bilateral distribution. The most common nail change on long second toe was melanonychia (23, 46%), followed by subungual hematoma (15, 30%), onycholysis (2, 4%), subungual hyperkeratosis (2, 4%), onychomadesis (1, 2%), and retronychia (1, 2%). The most common skin change was corn (9, 18%), followed by paronychia (2, 4%). Twenty (20/50, 40%) patients also had other toe or toenail changes. Among them, the most common site was big toe/nail (13, 62%), and the most common change was subungual hematoma (8, 42%). Conclusion: Through this study, the dermatologists can recognize and diagnose the nail and skin changes of long second toe.

Numerical analysis of flow and bed change at a confluence of the Namhan River and the Seom River using a two-dimensional model

Park Moonhyung,Kim Hyung Suk,Baek Chang Hyun 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.12

본 연구에서는 4대강 살리기 사업 후 퇴적현상이 지배적으로 발생하는 남한강과 섬강 합류부 구간을 대상으로 2차원 수치모형인 CCHE2D 모형을 이용하여 하천의 흐름 및 하상변동에 대한 해석을 수행하였다. 대상지점 합류부는 남한강 본류의 만곡부에 지류 섬강이 유입되는 특성을 갖는다. CCHE2D 모형은 비평형 유사이송을 해석하며 소류사와 부유사 조정거리가 중요한 입력변수로 대상지점에서는 소류사 조정거리가 하상변동에 가장 큰 영향을 주는 것으로 나타났다. 수치모의 결과 유량비(Qr) 변화가 남한강과 섬강 합류부 지점에서 흐름 및 하상변동에 영향을 미쳤으며, Qr≤ 2.5인 경우에는 합류전 본류의 유속이 증가하여 흐름박리구역을 감소시켰으며 이로 인해 합류부 내측의 퇴적이 감소하였다. Qr>2.5이면 합류부 구간에 퇴적이 증가하여 사주가 형성될 가능성이 높은 것으로 나타났다. 수치모의를 통해 2013년에 발생한 유량비 변화에 의해 합류부에 고정사 주가 형성된 것을 알 수 있었다. The flow and bed change were analyzed using the CCHE2D model, which is a two-dimensional numerical model, at a confluence of the Namhan River and Seom River where deposition occurs predominantly after the “Four Major Rivers Restoration Project.” The characteristic of the junction is that the tributary of Seom River joined into the curved channel of the main reach of the Namhan River. The CCHE2D model analyzes the non-equilibrium sediment transport, and the adaptation lengths for the bed load and suspended load are important variables in the model. At the target area, the adaptation length for the bed load showed the greatest influence on the river bed change. Numerical simulation results demonstrated that the discharge ratio (Qr) change affected the flow and bed change in the Namhan River and Seom river junction. When Qr ≤2.5, the flow velocity of the main reach increased before confluence, thereby reducing the flow separation zone and decreasing the deposition inside the junction. When Qr>2.5, there was a high possibility that deposition would be increased, thereby forming sand bar. Numerical simulation showed that a fixed sand bar has been formed at the junction due to the change of discharge ratio, which occurred in 2013.

Verification of efficacy as an ergogenic aid and safety in doping of sibjeondaebo-tang

( Hyun Hin Yoo ),( Geun Hoon Choi ),( Man Gyoon Lee ),( Chang Kyun Kang ),( Hyon Park ) 한국운동영양학회 2014 Physical Activity and Nutrition (Phys Act Nutr) Vol.18 No.2

Hyun Jin Yoo, Geun Hoon Choi, Man Gyoon Lee, Chang Kyun Kang and Hyon Park. Verification of efficacy as an ergogenicaid and safety in doping of sibjeondaebo-tang. JENB., Vol. 18, No. 2, pp.189-195, 2014 [Purpose]Various kinds of food substances from all over the world have been proposed to use as ergogenic aids for the additional improvement of exercise performance especially in athletes. Herb medicine which usually being applied for the cure of disease is used as a performance booster in several far eastern countries including Korea. Many scientists and coaches have asked very objective verifications on the realityof herb medicines practically used but never been scientifically elucidated well enough. In addition to the possibility as an ergogenicaid, the safety in doping is the critical factor to be examined thoroughly. In this study, Sibjeondaebo-Tang, a leading popular prescribed herb medicine in Korea, was examined. [Methods]After the intake of Sibjeondaebo-Tang, its effects on V˙O2max, recovery from fatigue, and doping safety through the official process as WADA suggested. Six volunteered male Taekwondo Pumsae players were subjected in a repeatedly examined protocol. [Results]First of all, every subjects showed ‘negative’ in doping test, and the treatment did not show any significant improvement on VO2max even though there was a significant decrease in blood lactate level on a step test. [Conclusion]In conclusion, Sibjeondaebo-Tang may have some limited effects as a fatigue delayer and the use of it showed safe to doping test with the strict limitation as the way in this study. So we should abstain from the over-interpreted application of the results so far. [Keywords]ergogenic aid, Doping, Taekwondo, Sibjeondaebo-Tang

A New MPEG-2 Rate Control Scheme Using Scene Change Detection

Park, Sang-Gyu,Lee, Young-Sun,Chang, Hyun-Sik Electronics and Telecommunications Research Instit 1996 ETRI Journal Vol.18 No.2

We propose two new rate control schemes to improve MPEG-2 rate control in view of visual quality when scene changes happen. Two proposed schemes are characterized by real-time and non real-time improvement to reduce the impact of scene changes. We also propose a new target-bit prediction method using spatial activity of pictures and present a simple and efficient scene change detection scheme using signed difference of mean absolute difference (MAD). Computer simulation results show that the proposed real-time algorithm effectively alleviates visual quality degradation after scene changes. The proposed non real-time algorithm gives maximum 2 dB improvement in peak signal-to-noise ratio (PSNR) at a scene-changed picture, compared with MPEG-2 rate control scheme and it shows better quality than the real-time one.

Sensitivity analysis of satellite-retrieved SST using IR data from COMS/MI

Park, Eun-Bin,Han, Kyung-Soo,Ryu, Jae-Hyun,Lee, Chang-Suk The Korean Society of Remote Sensing 2013 大韓遠隔探査學會誌 Vol.29 No.6

Sea Surface Temperature (SST) is the temperature close to the ocean's surface and affects the Earth's atmosphere as an important parameter for the climate circulation and change. The SST from satellite still has biases from the error in specifying retrieval coefficients from either forward modeling or instrumental biases. So in this paper, we performed sensitivity analysis using input parameter of the SST to notice that the SST is most affected among the input parameter. We used Infrared (IR) data from the Communication, Ocean, and Meteorological Satellite (COMS)/Meteorological Imager (MI) from April 2011 to March 2012. We also used the Global Space-based Inter-Calibration System (GSICS) correction to quality of the IR data from COMS. SST was calculated by substituting the input parameters; IR data with or without the GSICS correction. The results of this sensitivity analysis, the SST was sensitive from -0.0403 to 0.2743 K when the IR data were changed by the GSICS corrections.

Reconstruction of Anterior Chest Wall Defect Induced by Sterile Costochondritis: A Case Report of Non-radiographic Axial Spondyloarthritis

Park Sang Hyun,Jeong Sang Hyun,민경현,Chang Lan Sook 대한창상학회 2023 Journal of Wound Management and Research Vol.19 No.2

Non-radiographic axial spondyloarthritis (axSpA) is a subtype of axSpA characterized by chronic low back pain and stiffness but without radiographic evidence of sacroiliitis or spinal changes. As is the case with axSpA, early initiation of nonsteroidal anti-inflammatory drugs, tumor necrosis factor inhibitor agents, or physical therapy are often recommended for patients with non-radiographic axSpA. While the clinical course of non-radiographic axSpA is less well-known than axSpA, we present a case of a patient with non-radiographic axSpA manifesting as a sterile abscess in the sternum and costal cartilage. In this case report, we describe the diagnostic process for this rare manifestation and reconstruction of the large chest wall defect using a pedicled transverse rectus abdominis musculocutaneous flap.

흰쥐에서 분리 배양한 척수앞뿔신경세포의 형태 분화 및 축삭 형성

엄창섭,엄창섭,박창현,권계숙,유임주,박선화,전용혁 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.2

연령증가에 따른 혈압요소들의 좌심실비대 및 관동맥질환과의 관련성

박재석,박창규,박미영,박재형,김용현,나진오,신성희,서순용,홍순준,박성미,임홍의,김응주,서홍석,오동주,노영무 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2