• Title/Summary/Keyword: Brain drain

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Characteristics of Behavior of Brain Board - driven Clay Layers by Vacuum Loading (진공하중에 의한 Drain Board 타입 점토지반의 거동 특성)

  • Lee, Song;Yang, Tae-Seon;Park, Jong-Chan;Paik, Young-Shik
    • Geotechnical Engineering
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    • v.9 no.1
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    • pp.45-58
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    • 1993
  • Paper drain method is one of the methods used for the improvement of soft clay as hydraulic fill sites or the seaside industrial complex. This method adopts a card board as the drain materials instead of sand piles in sand drain method. In this paper 3 types of drain board are used to fond out the characteristics of consolidation by vacuum consolidation model test. So does the no drain board test. This test causes the reduction of pore water pressure to promote the settlement without change of ground water level. Conclusively, the vacuum consolidation shows 3-dimensional behaviors and pore water pressure reaches a negative value in a short time. In addition, it is expected to have a comparatively good consolidation effect using non -woven board, and vacuum loading results in increasing the shear strength at the bottom and top of call layers.

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Study on the Relationship of Brain and Heart Based on Oriental Medicine (뇌(腦)와 심(心)의 한의학적 상관성에 대한 연구)

  • Jo Hak-Jun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1496-1503
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    • 2005
  • This study aims to define the relationship between brain and heart through several literatures about oriental medicine and the conclusions are as follows. Heart in oriental medicine is called as Sinmyeongjishim(神明之心) which has a close connection with Mind, Consciousness, Emotion, and Physiological instinct of Drain in modern medicine. According to Oriental medicine, Brain stores Wonsin(元神) as Heart stores mind(神). Heart is where mind rests whereas Brain is where mind reveals. The external evidences that prove the relationship of Heart and Mind are as follows: First, with ears, eyes, mouth, and nose the subject of cognition is recognized as Sinmyeongjishim(神明之心). Second, Bulin(不仁), which means decreased movement power and sensibility of limbs, proves that Sinmyeongjishim(神明之心) is involved with movement power and sensibility of limbs. The physiological evidences that prove the relationship of Heart and Mind are as follows; First, Heart as the operation of Sinmyeongjishim(神明之心) manages language. Second, Heart is related with Tongue. Third, Heart is linked to Ears through the ear hole. Fourth, Heart is a store of Mind. Fifth, the five viscera control emotional and psychological activities. The pathological evidence of the relationship of Heart and Mind is that the symptoms of heart disease which are related to Sinmyeongjishim(神明之心) are also related to the functions of Brain. Though Brain has a close connection with Heart in oriental medicine, it is recognized that there are distinctive symptoms of disease of Brain and Hyeolyookjishim(血肉之心) respectively. The relationship of Heart and Brain has been researched in this study, even though there are not enough written materials about oriental medicine. But the fact that the majority of Heart operation is deeply connected with Brain activities cannot be denied. Therefore the research of Heart should be done as well as Brain in the clinical study of Brain.

The Changes of Cerebral Metabolic and Hemodynamic Parameters, Brain Histology, and Serum Levels of Neuron-Specific Enolase During Retrograde Cerebral Perfusion Under Pofound Hypothermic total Circulatory Arrest in Pigs (돼지에서 초저체온 순환정지 하의 역행성 뇌관류시 뇌대사, 혈류역학 지표, 뇌조직 소견 및 혈청 내 neuron-specific enolase의 변화)

  • Kim, Kyung-Hwan;Ahn, Hyuk
    • Journal of Chest Surgery
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    • v.33 no.6
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    • pp.445-468
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    • 2000
  • Background: Retrograde cerebral perfusion(RCP) is currently used for brain protection during aorta surgery, however, for the safety of it, various data published so far are insufficient. We performed RCP using pig and investiaged various parameters of cerebral metabolism and brain injury after RCP under deep hypothermia. Material and Method: We used two experimental groups: in group I(7 pigs, 20 kg), we performed RCP for 120 minutes and in group II (5 pigs, 20 kg), we did it for 90 minutes. Nasopharyngeal temperature, jugular venous oxygen saturation, electroencephalogram were continuously monitored, and we checked the parameters of cerebral metabolism, histological changes and serum levels of neuron-specific enolose(NSE) and lactic dehydrogenase(LDH). Central venous pressure during RCP was mainained in the range of 25 to 30 mmHg. Result: Perfusion flow rates(ml/min) during RCP were 130$\pm$57.7(30 minutes), 108.6$\pm$55.2(60 minutes), 107.1$\pm$58.8(90 minutes), 98.6$\pm$58.7(120 minutes) in group I and 72$\pm$11.0(30 minutes), 72$\pm$11.0(60 minutes), 74$\pm$11.4(90 minutes) in group II. The ratios of drain flow to perfusion flow were 0.18(30 minutes), 0.19(60 minutes), 0.17(90 minutes), 0.16(120 minutes) in group I and 0.21, 0.20, 0.17 in group II. Oxygen consumptions(ml/min) during RCP were 1.80$\pm$1.37(30 minutes), 1.72$\pm$1.23(60 minutes), 1.38$\pm$0.82(90 minutes), 1.18$\pm$0.67(120 minutes) in group I and 1.56$\pm$0.28(30 minutes), 1.25$\pm$0.28(60 minutes), 1.13$\pm$0.26(90 minutes). We could observe an decreasing tendency of oxygen consumption after 90 minutes of RCP in group I. Cerebrovascular resistance(dynes.sec.cm-5) during RCP in group I incrased from 71370.9$\pm$369145.5 to 83920.9$\pm$49949.0 after the time frame of 90 minutes(p<0.05). Lactate(mg/min) appeared after 30 minutes of RCP and the levels were 0.15$\pm$0.07(30 minutes), 0.18$\pm$0.10(60 minutes), 0.19$\pm$0.19(90 minutes), 0.18$\pm$0.10(120 minutes) in group I and 0.13$\pm$0.09(30 minutes), 0.19$\pm$0.03(60 minutes), 0.29$\pm$0.11(90 minutes) in group II. Glucose utilization, exudation of carbon dioxide, differences of cerebral tissue acidosis between perfusion blood and drain blood were maintained constantly during RCP. Oxygen saturation levels(%) in drain blood during RCP were 22.9$\pm$4.4(30 minutes), 19.2$\pm$4.5(60 minutes), 17.7$\pm$2.8(90 minutes), 14.9$\pm$2.8(120 minutes) in group I and 21.3$\pm$8.6(30 minutes), 20.8$\pm$17.6(60 minutes), 21.1$\pm$12.1(90 minutes) in group II. There were no significant changes in cerebral metabolic parameters between two groups. Differences in serum levels of NSE and LDH between perfusion blood and drain blood during RCP showed no statistical significance. Serum levels of NSE and LDH after resuming of cardipulmonary bypass decreased to the level before RCP. Brain water contents were 0.73$\pm$0.03 in group I and 0.69$\pm$0.06 in group II and were higher than those of the controls(p<0.05). The light microscopic findings of cerebral neocortex, basal ganglia, hippocampus(CA1 region) and cerebellum showed no evidence of cerebral injury in two groups and there were no different electron microscopy in both groups(neocortex, basal ganglia and hippocampus), but they were thought to be reversible findings. Conclusion: Although we did not proceed this study after survival of pigs, we could perform the RCP successfully for 120 minutes with minimal cerebral metabolism and no evidence of irreversible brain damage. The results of NSE and LDH during and after RCP should be reevaluated with survival data.

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A Study on the Critical Factors that Affect Korean Students' Decision to Return to Korea after Graduating from the Top 5 Universities in USA (미국 과학기술분야 Top 5 대학 유학생의 귀국 의사결정 요인 분석)

  • Heo, Dae Nyoung;Lee, Jun Young;Jeong, Naeyang;Ku, Bon Chul;Song, Choonghan
    • Journal of Korea Technology Innovation Society
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    • v.17 no.1
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    • pp.264-288
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    • 2014
  • The competition for attracting outstanding HRST (human resource for science and technology) who can lead technological innovation is heating up all over the world. The various concepts, which are brain drain, brain gain, brain overflow, brain migration, brain circulation, are used to explain the international mobility of HRST. But the concept of brain scout is the more adequate for explaining in the case of outstanding HRST as the main cause of excessive competition for scouting. This study analyzed the critical factors of the determinants of Korean students in the USA who have intentions of returning to Korea in view of brain scout. As the first step in this study, potential factors and hypothesis are established by the interviews. As the second step, the major factors are examined by surveys and hypothesis testing. Also, a new model for decision-making is proposed which describes intentions of returning to Korea by logistic regression analysis and contributions of each factor derived from this study were compared. Finally, policy implications for attracting outstanding HRST and the limit of this study are discussed.

Automated Brain Region Extraction Method in Head MR Image Sets (머리 MR영상에서 자동화된 뇌영역 추출)

  • Cho, Dong-Uk;Kim, Tae-Woo;Shin, Seung-Soo
    • The Journal of the Korea Contents Association
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    • v.2 no.3
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    • pp.1-15
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    • 2002
  • A noel automated brain region extraction method in single channel MR images for visualization and analysis of a human brain is presented. The method generates a volume of brain masks by automatic thresholding using a dual curve fitting technique and by 3D morphological operations. The dual curve fitting can reduce an error in clue fitting to the histogram of MR images. The 3D morphological operations, including erosion, labeling of connected-components, max-feature operation, and dilation, are applied to the cubic volume of masks reconstructed from the thresholded Drain masks. This method can automatically extract a brain region in any displayed type of sequences, including extreme slices, of SPGR, T1-, T2-, and PD-weighted MR image data sets which are not required to contain the entire brain. In the experiments, the algorithm was applied to 20 sets of MR images and showed over 0.97 of similarity index in comparison with manual drawing.

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Science and Technology Human Resource Capacity for Economic Growth: The Case of Korea

  • Park, Myungsoo
    • STI Policy Review
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    • v.1 no.2
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    • pp.19-31
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    • 2010
  • This paper presents the policies Korea adopted to educate and train scientists/researchers and technicians/skilled workers. The Korean policies for the increase of human resources in science and technology that stimulated an upgrading of skills in industry and adapted to technical advancements are identified. An important factor is that the supply and demand mechanism created a virtuous circle so that the science and technology education and training policies were responsive to economic demands. In addition, policies to foster a human resource capacity have enhanced the contribution of human resources in science and technology for innovation and economic growth.

Burr Hole Drainage : Could Be Another Treatment Option for Cerebrospinal Fluid Leakage after Unidentified Dural Tear during Spinal Surgery?

  • Huh, Jisoon
    • Journal of Korean Neurosurgical Society
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    • v.53 no.1
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    • pp.59-61
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    • 2013
  • Authors report a rare case of acute intracranial subdural and intraventricular hemorrhage that were caused by intracranial hypotension resulted from cerebrospinal fluid leakage through an unidentified dural tear site during spinal surgery. The initial brain computed tomography image showed acute hemorrhages combined with preexisting asymptomatic chronic subdural hemorrhage. One burr hole was made over the right parietal skull to drain intracranial hemorrhages and subsequent drainage of cerebrospinal fluid induced by closure of the durotomy site. Among various methods to treat cerebrospinal fluid leakage through unidentified dural injury site, primary repair and spinal subarachnoid drainage are well known treatment options. The brain imaging study to diagnose intracranial hemorrhage should be taken before selecting the treatment method, especially for spinal subarachnoid drainage. Similar mechanism to its spinal counterpart, cranial cerebrospinal fluid drainage has not been mentioned in previous article and could be another treatment option to seal off an unidentified dural tear in particular case of drainage of intracranial hemorrhage is needed.

Immediate Postoperative Epidural Hematomas Adjacent to the Craniotomy Site

  • Jeon, Jin-Soo;Chang, In-Bok;Cho, Byung-Moon;Lee, Ho-Kook;Hong, Seung-Koan;Oh, Sae-Moon
    • Journal of Korean Neurosurgical Society
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    • v.39 no.5
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    • pp.335-339
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    • 2006
  • Objective : The authors present eight cases of immediate post-operative epidural hematomas[EDHs] adjacent to the craniotomy site, describe clinical details of them, and discuss their pathogenesis. Methods : Medical records of eight cases were retrospectively reviewed and their clinical data, operation records, and radiological findings analyzed. Any risk factors of the EDHs were searched. Results : In 5 of 8 cases, adjacent EDHs developed after craniotomies for the surgical removal of brain tumors. Three cases of adjacent EDHs developed after a pterional approach and neck clipping of a ruptured anterior communicating artery aneurysm, a ventriculoperitoneal shunt, and a craniotomy for a post-traumatic EDH, respectively. In all eight cases, brain computed tomography[CT] scans checked immediately or a few hours after the surgery, revealed large EDHs adjacent to the previous craniotomy site, but there was no EDH beneath the previous craniotomy flap. After emergent surgical removal of the EDHs, 7 cases demonstrated good clinical outcomes, with one case yielding a poor result. Conclusion : Rapid drainage of a large volume of cerebrospinal fluid or intra-operative severe brain collapse may separate the dura from the calvarium and cause postoperative EDH adjacent to the previous craniotomy site. A high-pressure suction drain left in the epidural space may contribute to the pathogenesis. After the craniotomy for brain tumors or intracranial aneurysms, when remarkable brain collapse occurs, an immediate postoperative brain CT is mandatory to detect and adequately manage such unexpected events as adjacent EDHs.

Rapid Development of Brain Abscess Caused by Streptococcus Pyogenes Following Penetrating Skull Injury via the Ethomoidal Sinus and Lamina Cribrosa

  • Gulsen, Salih;Aydin, Gerilmez;Comert, Serhat;Altinors, Nur
    • Journal of Korean Neurosurgical Society
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    • v.48 no.1
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    • pp.73-78
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    • 2010
  • Objective : Streptococcus pyogenes is a beta-hemolytic bacterium that belongs to Lancefield serogroup A, also known as group A streptococci (GAS). There have been five reported case in terms of PubMed-based search but no reported case of brain abscess caused by Streptococcus pyogenes as a result of penetrating skull injury. We present a patient who suffered from penetrating skull injury that resulted in a brain abscess caused by Streptococcus pyogenes. Methods : The patient was a 12-year-old boy who fell down from his bicycle while cycling and ran into a tree. A wooden stick penetrated his skin below the right lower eyelid and advanced to the cranium. He lost consciousness on the fifth day of the incident and his body temperature was measured as $40^{\circ}C$. While being admitted to our hospital, a cranial computed tomography revealed a frontal cystic mass with a perilesional hypodense zone of edema. There was no capsule formation around the lesion after intravenous contrast injection. Paranasal CT showed a bone defect located between the ethmoidal sinus and lamina cribrosa. Results : Bifrontal craniotomy was performed. The abscess located at the left frontal lobe was drained and the bone defect was repaired. Conclusion : Any penetrating lesion showing a connection between the lamina cribrosa and ethmoidal sinus may result in brain abscess caused by Streptococcus pyogenes. These patients should be treated urgently to repair the defect and drain the abscess with appropriate antibiotic therapy started due to the fulminant course of the brain abscess caused by this microorganism.

What Drives Skilled Migration? Cross-country Evidence, 1990~2000 (숙련노동력 이민의 경제적 요인: 국가수준 횡단면 분석, 1990~2000)

  • Lee, Changkeun
    • Journal of Labour Economics
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    • v.29 no.2
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    • pp.1-27
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    • 2006
  • Recent migration is led by skilled labor, This paper performes a cross-country analysis to find the determinants of skilled migration using recently released Doquier and Marfouk(2005) data as dependent variable and economic indicators of nations as independent variables. Regression results show that the skilled migration to OECD countries are driven not only by income motive but also by structural factors, such as industrial structure and life expectancy, which have broader meanings in development. It is noteworthy that structural factors of a nation become more important as its income level rises. English seems to have positive effect on skilled migration. Some region-specific factors, proximity to USA of Caribbean countries and political instability of Gold Coast countreis, for example, are found. Middle-income countries seem to be the most vulnerable to the possible risk of brain drain.

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