• BMB Reports
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• v.45 no.8
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• pp.464-469
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• 2012

Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. MiRNA let-7 family is known to be involved in the regulation of cell apoptosis. However, the function of let-7 in ox-LDL induced ECs apoptosis and atherosclerosis is still unknown. Here, we show that let-7c expression was markedly up-regulated in ox-LDL induced apoptotic human umbilical cord vein endothelial cells (HUVECs). Let-7c over-expression enhanced apoptosis in ECs whereas inhibition of let-7c could partly alleviate apoptotic cell death mediated by ox-LDL. Searching for how let-7c affected apoptosis, we discovered that antiapoptotic protein Bcl-xl was a direct target of let-7c in ECs. Our data suggest that let-7c contributes to endothelial apoptosis through suppression of Bcl-xl.

• Knowledge Management Research
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• v.11 no.5
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• pp.79-90
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• 2010

As the volume of South Korean trading increased, the pressure from the international community on South Korea to perform export control system for strategic items (ECS) increased as well. However, the South Korean government has been giving a tepid response toward the ECS, due to lack of the knowledge on psychological reactance of firms. This paper investigates the structural relationships between environmental factors and the attitude toward the ECS, and the adoption of the ECS. The author discuss the implications of the findings in this article which are useful for the government to find strategic policy direction.

• Ocean and Polar Research
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• v.34 no.2
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• pp.219-228
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• 2012

Tintinnid species distribution has been monitored in the northern East China Sea (ECS) in the summer of 2006 through 2011. This is used to understand the water mass movements in the northern ECS. The warm oceanic tintinnid species had largely spread in 2007 in the area, indicating that there was greater warm water extension into the northern ECS. However the extension of neritic water within the Changjiang diluted water mass has strengthened in 2008 and 2010 because the neritic species distribution had relatively grown in both years. These annual results based on the biological indicators of tintinnid species are well matched with the salinity change in the area. The warm oceanic species, Dadayiella ganymedes had frequently occurred over the study years and had shown a significant relationship with the salinity change. This is valuable as a key stone species for monitoring the intrusion of the Kuroshio within the northern ECS. Information from tintinnid biological indicators can support physical oceanography data to confirm ambiguous water mass properties.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4560-4570
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• 2022

Dynamic fault tree (DFT) and its related research methods have received extensive attention in safety analysis and reliability engineering. DFT can perform reliability modelling for systems with sequential correlation, resource sharing, and cold and hot spare parts. A technical modelling method of DFT is proposed for modelling ship collision accidents and loss-of-coolant accidents (LOCAs). Qualitative and quantitative analyses of DFT were carried out using the cutting sequence (CS)/extended cutting sequence (ECS) method. The results show nine types of dynamic fault failure modes in ship collision accidents, describing the fault propagation process of a dynamic system and reflect the dynamic changes of the entire accident system. The probability of a ship collision accident is 2.378 × 10^-9 by using CS. This failure mode cannot be expressed by a combination of basic events within the same event frame after an LOCA occurs in a marine nuclear reactor because the system contains warm spare parts. Therefore, the probability of losing reactor control was calculated as 8.125 × 10^-6 using the ECS. Compared with CS, ECS is more efficient considering expression and processing capabilities, and has a significant advantage considering cost.

• Proceedings of the KSRS Conference
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• v.2
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• pp.740-743
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• 2006

We identify two distinct finer-scale frontal bands: 'Mainland China Coastal Front' (MCCF) and 'Kuroshio Front' (KF). The MCCF is along the 50-m isobath with large temperature gradient. The front is a boundary between the Mainland China Coastal Current and the offshore shelf waters. On the other hand, the KF is extending from the northeastern coast of Taiwan toward the northeast and into the shelf of south ECS. It forms a broad semicircle-shape and curving along 100-m isobath, it also deviates from eastward at around 26.5N-122E and leaves the shelf of ECS. This front should be the boundary between the Kuroshio water and the other shelf waters.

• Ocean and Polar Research
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• v.32 no.4
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• pp.351-359
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• 2010

This study examined extensive patches of floating green macroalgal (Ulva prolifera) mats in the northern East China Sea (ECS) using satellite images from mid May through July 2008 and field observation made during early August 2008 cruise. It was previously reported that the massive macroalgal blooms occurred in the coastal areas of Qingdao in China. During our field survey, researchers noticed widely distributed floating patches of macroalgal mats ranging in size from tens of centimeters to a few hundred meters in diameter. Meteorological data in the northern ECS showed high irradiance, high air-temperature, and predominant southerly winds in summer. In the study area during the survey period, surface waters were characterized by the Changjiang Diluted Water (CDW) mass, which contained high concentrations of nitrate and phosphate. The internal transcribed spacer (ITS) sequence of U. prolifera found in the northern ECS was the same as those of U. prolifera sampled from Qingdao blooms, suggesting a possibility that U. prolifera found in two regions would be derived from the same origin. We suggest that U. prolifera in the nearshore Jiangsu Province drifted into the northern ECS and proliferated under favorable meteorological and oceanographic conditions during the summer of 2008.

• Ocean and Polar Research
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• v.35 no.2
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• pp.147-155
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• 2013

The purpose of this study is to investigate seasonal difference in linear trends in satellite-derived chlorophyll-a concentration (Chl-a) and their related environmental changes in the South Sea of Korea (SSK) and East China Sea (ECS) for recent 15 years (Jan. 1998~Dec. 2012) by analyzing climatological data of Chl-a, Rrs(555), sea surface wind (SSW) and nutrient. A linear trend analysis of Chl-a data reveals that, during recent 15 years, the spring bloom was enhanced in most of the ECS, while summer and fall blooms were weakened. The increased spring (Mar. - May) Chl-a was associated with strengthened winter (Dec. - Feb.) wind that probably provided more nutrient into the upper ocean from the deep. The causes of decreased summer (Jun. - Aug.) Chl-a in the northern ECS were uncertain, but seemed to be related with the nutrient limitation. Recently (after 2006), low-salinity Changjiang diluted water in the south of Jeju and the SSK had lower phosphate that caused increase in N/P ratio with Chl-a decrease. The decreased fall (Sep. - Nov.) Chl-a was associated with weakened wind that tends to entrain less nutrient into the upper ocean from the deep. This study suggests that phytoplankton in the ECS differently changes in response to environmental changes depending on season and region.

• Health Policy and Management
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• v.29 no.1
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• pp.4-10
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• 2019

The term new tobacco products (NTPs) refers to the new alternatives to conventional cigarettes. There are several kinds of NTPs in South Korea. The present study discusses the most widely used NTPs namely electronic cigarette (ECs) and heated tobacco products (HTPs). The aims of this study are to evaluate the risk related to the use of ECs and HTPs, introduce policy examples across different countries of management of this issue, and finally, present some policy implications of the problem and our response strategies. Since the advent of ECs, there has been a lot of debate about its risk. Some studies have reported that ECs are less harmful than conventional cigarettes and that they are effective in aiding smoking cessation. Nevertheless, the efficacy of ECs in smoking cessation and its potential health risks are still unclear. However, the obvious fact is that it is not harmless. Regulations on ECs differ from country to country. In many countries, they are strictly regulated as tobacco or toxic substances; however, in the United Kingdom, the use of ECs are included as part of their smoking cessation policy, and in Japan, they are treated as a form of medication. On the other hand, HTPs are the most recently introduced NTPs and they have attained sensational popularity because of the wrongly held belief that they are less harmful to health. So, what about our policy response to these two tobacco products? The research on ECs requires more systematic statistical monitoring, such as monitoring the ratio of dual-users. Further, the new EC smokers should be identified taking into account that the arguments for the use of ECs often emphasize smoking cessation or less risks to health, the government should further strengthen its policy to prevent those claims. The HTPs market experienced a very sharp growth and continues to grow because the government policy is too passive. Taking this as a lesson, it is necessary to approach NTPs, such as HTPs, proactively and increase their contribution to the National Health Promotion Fund by imposing greater taxes on them. Finally, considering the likelihood of NTPs being promoted as a less harmful tobacco product, it is essential to strictly regulate tobacco companies' publicity from the very beginning to ensure that potential consumer s are not mislead.

• Atmosphere
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• v.16 no.1
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• pp.33-48
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• 2006

A classification of snowfall type based on development mechanism is proposed using previous snowfall studies, operational experiences, etc. Five types are proposed: snowfall caused by 1) airmass transformation (AT type), 2) terrain effects in a situation of expanding Siberian High (TE type), 3) precipitation systems associated with extratropical cyclones (EC type), 4) indirect effects of extratropical cyclones passing over the sea to the south of the Korean peninsula (ECS type), and 5) combined effects of TE and ECS types (COM type). Snowfall events during 1981-2001 are classified according to the 5 types mentioned above. For this, 118 events, with at least one station with daily snowfall depth greater than 20 cm, are selected. For the classification, synoptic weather charts, satellite images, and precipitation data are used. For TE and COM types, local sea-level pressure chart is also used to confirm the presence of condition for TE type (this is done for events in 1990 and thereafter). The classification shows that 109 out of 118 events can be classified as one of the 5 types. In the remaining 8 events, heavy snowfall occurred only in Ullung Island. Its occurrence may be due to one or more of the following mechanism: airmass transformation, mesoscale cyclones and/or mesoscale convergence over the East Sea, etc. Each type shows different characteristics in location of snowfall and composition of precipitation (i.e., dry snow, rain, and mixed precipitation). The AT-type snowfall occurs mostly in the west coast, Jeju and Ullung Islands whereas the TE-type snowfall occurs in the East coast especially over the Young Dong area. The ECS-type snowfall occurs mostly over the southern part of the peninsula and some east cost area (sometimes, whole south Korea depending on the location of cyclones). The EC- and COM-type snowfalls occur in wider area, often whole south Korea. Precipitation composition also varies with the type. The AT-type has a snow ratio (SR) higher than the mean value. The TE- and EC-type have SR similar to the mean. The ECS- and COM-type have SR values smaller than the mean. Generally the SR values at high latitude and mountainous areas are higher than those at the other areas. The SR value informs the characteristics of the precipitation composition. An SR value larger than 10 means that all precipitation is composed of snow whereas a zero SR value means that all precipitation is composed of rain.

• Journal of the korean society of oceanography
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• v.32 no.1
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• pp.1-7
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• 1997

Surface current fields in the eastern East China Sea (ECS) were constructed by analyzing trajectories of 58 satellite-tracked surface drifters released during 1991-1996. Composite trajectories and 20-minute-by-20-minute box-averaged current vectors show that the basic current pattern composes of: the Kuroshio main stream, which turns eastward toward the Tokara Strait; a northward branch current of the Kuroshio on the ECS outer shelf deeper than 100 m; and an anticyclonic circulation in the northern Okinawa Trough west of Kyushu. The northward branch current sharply changes its direction to the northeast when it crosses a line connecting Cheju Island, Korea and Goto Islands, Japan. The basic pattern of current field changes slightly from winter to summer, and the main axis of the Tsushima Current in the Korea Strait is found to shift seasonally. The drifter experiment does not support the claim that the Yellow Sea Warm Current is separated from the northward branch current on the outer shelf southeast of Cheju Island. We suggest that the use of the term 'Tsushima Current' be limited to the northeast channel flow in the Korea Strait. The new term 'Kuroshio Branch Current' is suggested for the northward branch current on the outer shelf south of Cheju-do, which is separated from the Kuroshio.