Chung-Ang University

About: Chung-Ang University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Thin film. The organization has 13381 authors who have published 26978 publications receiving 416735 citations. The organization is also known as: CAU & Chung.

Using Collaborative Assessment to Examine the Relationship between Self-Reported Beliefs and the Documentable Practices of Preschool Teachers

Abstract: A team of researchers used a collaborative assessment protocol to compare the self-reported teaching beliefs of a convenience sample of preschool teachers (N = 57) to their documentable practices (i.e., practices that could be observed, recorded, and categorized using a deductive strategy). Data were examined from survey instruments, detailed classroom observations and time-sampling, curriculum materials, and program artifacts. Results indicated that when child-directed choice/play time, emergent literacy and language development activities were emphasized, teachers self-reported beliefs were more strongly aligned with developmentally appropriate practice (DAP) as a philosophy of practice. When consistent routines, organized classrooms, preplanned curriculum, and teacher-directed learning were the dominant behaviors, the teachers were found to report more “traditional” or academic-oriented beliefs.

Human microglia transplanted in rat focal ischemia brain induce neuroprotection and behavioral improvement.

Abstract: Background and Purpose Microglia are resident immunocompenent and phagocytic cells of central nervous system (CNS), which produce various cytokines and growth factors in response to injury and thereby regulate disease pathology. The purpose of this study is to investigate the effects of microglial transplantation on focal cerebral ischemia model in rat. Methods Transient middle cerebral artery occlusion (MCAO) in rats was induced by the intraluminal filament technique. HMO6 cells, human microglial cell line, were transplanted intravenously at 48 hours after MCAO. Functional tests were performed and the infarct volume was measured at 7 and 14 days after MCAO. Migration and cell survival of transplanted microglial cells and host glial reaction in the brain were studied by immunohistochemistry. Gene expression of neurotrophic factors, cytokines and chemokines in transplanted cells and host rat glial cells was determined by laser capture microdissection (LCM) and quantitative real time-PCR. Results HMO6 human microglial cells transplantion group demonstrated significant functional recovery compared with control group. At 7 and 14 days after MCAO, infarct volume was significantly reduced in the HMO group. In the HMO6 group, number of apoptotic cells was time-dependently reduced in the infarct core and penumbra. In addition, number of host rat microglia/macrophages and reactive astrocytes was significantly decreased at 7 and 14 days after MCAO in the penumbra. Gene expression of various neurotrophic factors (GDNF, BDNF, VEGF and BMP7) and anti-inflammatory cytokines (IL4 and IL5) was up-regulated in transplanted HMO6 cells of brain tissue compared with those in culture. The expression of GDNF and VEGF in astrocytes in penumbra was significantly up-regulated in the HMO6 group. Conclusions Our results indicate that transplantation of HMO6 human microglial cells reduces ischemic deficits and apoptotic events in stroke animals. The results were mediated by modulation of gliosis and neuroinflammation, and neuroprotection provided by neurotrophic factors of endogenous and transplanted cells-origin.

Influence of pregnancy on neuromyelitis optica spectrum disorder.

Abstract: Objective: To investigate the influence of pregnancy on patients with neuromyelitis optica spectrum disorder (NMOSD). Methods: A total of 190 women with NMOSD were enrolled from 7 referral hospitals in 4 countries. We reviewed medical records and used a structured questionnaire to investigate gravidity, parity, and the number of relapses during the 2 years before pregnancy, during each trimester of pregnancy, during the first and second trimesters after delivery, and for 6 months thereafter. The annualized relapse rate (ARR) was calculated for each period. Results: Of the 190 women with NMOSD, 40 patients experienced 54 informative pregnancies, and all of them were seropositive for aquaporin-4 antibody. Fourteen patients developed the first symptoms of NMOSD either during the pregnancy (3 patients) or within a year after delivery or abortion (8 and 3 patients, respectively). Twenty-six patients experienced 40 pregnancies after the onset of NMOSD (26 deliveries and 14 abortions [1 spontaneous and 13 elective]). There was one preterm delivery with birth defects and no stillbirths. The ARR during pregnancy did not differ from that before pregnancy, but it increased significantly during the first and second trimesters after delivery (5.3 and 3.7 times, respectively). Moreover, 77% of the deliveries were associated with postpartum relapses. Conclusion: The significantly increased relapse rate and numerous cases of NMOSD onset after pregnancy suggest that delivery adversely affects the course of NMOSD. Prospective studies are needed to confirm our findings.

Frequency-offset synchronization and channel estimation for OFDM-based transmission

Abstract: This letter is concerned with a frequency offset estimation technique for OFDM based transmission systems. The frequency estimation technique utilizes a repetitive signal structure inside of a OFDM symbol which is used to enlarge the range and increase the accuracy of offset estimation. Also, an averaged decision-directed channel estimation (ADDCE) technique suitable for burst data is proposed.