• Title/Summary/Keyword: Migration process

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배양된 해마 신경세포의 성장에 대한 납의 영향

  • 김율아;김종곤;김용식;김영희;송동근
    • Toxicological Research
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    • v.9 no.2
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    • pp.207-215
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    • 1993
  • Lead is an environmental toxicant that causes a marked deficit in cognative development in infants and children. Damage to the hippocampus has been linked to the lead-induced deficit in the learning process. The present study examined the effects of lead on the development of hippocampal neurons in vitro. Hippocampal neurons were incubated with various concentrations in lead acetate (1nM to 30 nM) for 72 hrs from 4 h after plating, and the percentage of living neurons bearing neurites, neurite outgrowth and migration of multipolar neurons in culture were determined.

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Fabrication of electro phoresis microchips and effects of channel surface properties (마이크로 전기영동 소자의 제작과 유로 면 특성에 따른 전기삼투 및 전기영동 효과)

  • Kim, Min-Su;Cho, Seung-Il;Lee, Kook-Nyung;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2003.10a
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    • pp.286-289
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    • 2003
  • We investigated the influence of the properties of substrate material on the separation efficiency in microchip electrophoresis. We fabricated the various microchips and studied separation efficiency in microchannels composed of a single material such as quartz, glass, polydimethylsiloxane (PDMS), and polymethylmetha crylate (PMMA), as well as hybrid micro channels composed of different materials. New fabrication process for glass chip was suggested and some treatment is added to improve fabrication process in other chip. Separation efficiency was compared by measuring migration times and bandwidths of EOF and analytes in each microchip. The efficiency is the function of migration time, which is affected by the electroosmotic flow (EOF), and bandwidth of an analyte. EOF is highly dependent upon the characteristics of a microchannel wall surface. Migration time was more reproducible in silica chips than that of PDMS chip and more band broadening was observed in the microchip composed of hybrid material due to non-uniformity of surface charge density at the walls of the channel.

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Understanding of migration experiences and mental health among Korean immigrant youth (한국 이주배경 청소년의 이주경험과 정신건강)

  • Ryou, Bee;Choi, Jungtae;Sohn, Yejin;Kim, Kihyun
    • Journal of the Korean Society of Child Welfare
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    • no.58
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    • pp.231-262
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    • 2017
  • South Korea has long been a culturally homogenous society, yet the increasing number of immigrants has turned the country into a multicultural society. Therefore, many empirical studies have investigated the way immigrants adapt to the Korean society and its associated factors. However, examining the overall process of migration (from family separation to reunification and cultural adaptation to the host society) that immigrant youth usually experience has been understudied. Previous empirical research and theoretical work have identified prominent factors that predict immigrant youth's mental health: experiences of family separation, living with others rather than primary caretakers during the separation, the length of residency in the host society, and family and peer support. In this respect, this exploratory and preliminary study that examined whether the experience of migration process and post-migration are related to Korean immigrant youth's mental health problems (depression, anxiety, and suicidal ideation). The result indicated that longer duration of family separation; living with relatives, siblings; and friends rather than primary caretakers during the separation; receiving less support from family and peer after migration; and a lower degree of cultural adaptation to Korean culture were associated with depression, anxiety, and suicidal ideation. Drawing upon the results, this study discussed implications for policy and practice.

Speedup of Sequential Program Execution on a Network of Shared Workstations

  • Cho, Sung-Hyun;Jun, Sung-Syck
    • Journal of Electrical Engineering and information Science
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    • v.2 no.6
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    • pp.183-190
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    • 1997
  • We present competition protocols to speed up the execution of sequential programs on a network of shared workstations in the background by exploiting their wasted computing capacity, without interfering with processes of workstation owners. In order to argue that competition protocols are preferable to migration protocols in this situation, we derive the closed form solutions for the speedup of competition protocols and migration protocols, and simulate both of protocols under comparable overhead assumptions. Based on our analytic results and simulation results, we show that competitive execution is superior to process migration, and that competitive execution can finish sequential programs significantly faster than noncompetitive execution, especially when the foreground load is sufficiently high.

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Ritualism versus Universalism: The Challenge of Establishing an Effective Rights-Based Labor Migration Regime in ASEAN

  • Tigno, Jorge V.
    • SUVANNABHUMI
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    • v.11 no.2
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    • pp.159-186
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    • 2019
  • Southeast Asia accounts for nearly a tenth of total worldwide cross-border movements of migrant workers. Cambodia, Indonesia, Laos, Myanmar, and Philippines make up the sending countries while Malaysia, Singapore, and Thailand are the major destinations. Migrant worker movements are predominantly in production process and low- to medium-skilled sectors. It is not unusual for irregular or undocumented movements to take place. In not a few instances, migrants work under harsh and exploitative conditions. In recent years, however, ASEAN has taken steps to manage labor migration at the regional level. The paper argues that ASEAN has not managed these cross-border labor flows as well as it should particularly in terms of protecting and promoting the human rights of migrants. It will be difficult to establish the genuine building blocks for a regional human rights mechanism unless there is a diffusion of alternative universal norms and standards to what ASEAN already embodies. As long as states resist any attempt to weaken or question or deligitimize their capacity to determine who gets to enter, stay, and leave their jurisdictions, it will be difficult to establish an effective migrant rights framework for the region.

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Platform Design for Optimal Migration Cost of Mobile Agents (이동 에이전트의 최적 이주 비용을 위한 플랫폼 설계)

  • 김완성;복경수;신재룡;유재수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.1
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    • pp.137-149
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    • 2004
  • A new software paradigm is required on the development of network and various service requirements. With this, many studies on a mobile agent have been made. For the execution of the mobile agent, migration is the most important factor that influences the performance of the mobile agent. In this paper we propose the method that leads to high migration efficiency in order to improve the performance. The features of our migration technique are as follows. First, the migration technique creates the dynamic itinerary that appropriately copes with the network conditions and the platform changes to improve the agent execution efficiency. Second, it perfecters an executed code to reduce the amount of the mobile data and reduces the execution time by instantiating the agent in advance. Third, it improves the execution efficiency by using the checkpoint-based recovery method that does not execute the agent again and recovers the process states even though the errors take place. Though the simulation we compare the proposed method with the existing methods. The simulation result shows that the proposed method outperform the existing methods in terms of migration.

Monitoring of heavy metals, bisphenol A and phenol migrated from food packages for delivery

  • Cho, Hyunnho;Yun, Ho Cheol;Lee, Ji Yoon;Kwon, Hyeon Jeong;Jeong, Eun Jung;Kim, Da Young;Lee, Seong Ju;Kang, Jung Mi
    • Analytical Science and Technology
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    • v.35 no.1
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    • pp.15-23
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    • 2022
  • Food delivery is gaining popularity due to changes in lifestyle and dietary patterns. However, packages used to delivery food may contain contaminants including heavy metals, or additives added during manufacturing process which may migrate into food during processing and transportation. In this study, a total of 58 food packages for delivery were collected and tested for migration of heavy metals (lead, cadmium and arsenic), bisphenol A and phenol into food simulants. The method was validated by evaluating linearity of calibration curve, limit of detection, limit of quantification, recovery and precision. Result of heavy metal migration showed that lead was the most frequently migrated metal and the highest concentration was detected in a polypropylene sample. Although there are no specific migration limits for bisphenol A and phenol in packaging materials tested in this study, migrations of bisphenol A and phenol were detected in some packages. This may due to contamination or additives added during manufacture of packages. Risk (%) was calculated to analyze the risk associated with the migration of heavy metals, bisphenol A and phenol, and was always below 1 %. These results showed that food packages for delivery are safe in terms of heavy metals, bisphenol A and phenol migration.

Characterization of the KG1a Cell Line for Use in a Cell Migration Based Screening Assay

  • Bernhard O. Palsson;Karl francis;Lee, Gyun-Min
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.3
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    • pp.178-184
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    • 2002
  • High-throughput screening has become a popular method used to identify new “leads”for potentially therapeutic compounds. Further screening of these lead compounds is typically done with secondary assays which may utilize living, functioning cells as screening tools. A problem (or benefit) with these cell-based assays is that living cells are very sensitive to their environment. We have been interested in the process of stem cell migration and how it relates to the cellular therapy of bone marrow transplantation. In this study we describe a secondary, cell-based assay for screening the effects of various in-vitro conditions on Immature Hematopoietic Cell (IHC) migration. Our results have revealed many subtle factors, such as the cell's adhesive characteristics, or the effect of a culture's growth phase, that need to be accounted for in a screening protocol. Finally, we show that exponentially glowing KG1a cells (a human IHC cell line) were 10 times more motile than those in the lag or stationary phases. These data strongly suggest that KG1a cells secrete a chemokinetic factor during the exponential growth phase of a culture.