• The Korean Journal of Applied Statistics
• /
• v.31 no.5
• /
• pp.637-653
• /
• 2018

Rapid aging of the population affects population structure and population aging. Consequently, developed countries have focused on population aging as a major issue in regards to pension sustainability finances as well as health and the elderly welfare system. Mortality projections that result from population structure changes and population aging are increasingly important. This paper compares six mortality models using KOSTAT's life table from 1970 to 2016. The models are rooted in the Lee-Carter (LC) model (Lee and Carter, Journal of the American Statistical Association, 87, 659-671, 1992) and have been modified and improved on the assumptions of the LC model. We examined the improvement process and the check assumption by models in order to find a suitable mortality model for Korea. Korea shows rapid aging and declined mortality rate by age; therefore, it is desirable to estimate and predict mortality from LL&LC-ER models by combining LC-ER, LL, and LC-ER models that reflect the phenomena and modify age-specific mortality patterns without major changes in expected life expectancy.

• Toxicological Research
• /
• v.31 no.4
• /
• pp.331-337
• /
• 2015

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC ($10^{-6}M$) and CP ($10^{-5}M$) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 ($10^{-8}M$), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, $ER{\alpha}$ expression was not significantly changed by LC and CP, while down-regulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model.

• Tribology and Lubricants
• /
• v.14 no.2
• /
• pp.42-48
• /
• 1998

Electro-Rheological (ER) fluid is a class of functional fluid whose apparent viscosity can be varied by the applied electric field strength. The ER fluid is classified into two types; one is a dispersive fluid and the other is a homogeneous. Dispersive ER fluid is a colloidal suspension of fine semiconducting particles in a dielectric liquid and liquid crystal (LC) is classed as homogeneous type ER fluid. LC has been originally developed for some electronic display devices. Various mechanical components applying ER fluid have been developed, and the their performance typically depends on the characteristics of ER fluid which have generally been evaluated by a rotational viscometer. However, the ER fluid introduced into various mechanical components undergoes not only simple shear flow but press flow or oscillating flow. For the evaluation of ER fluid, the authors developed an reciprocating type viscometer. The amplitude is controlled on 5 mm at the frequency from 50 to 1000 Hz. In the present paper, the performance of several types of ER fluid is evaluated by the reciprocating type viscometer and compared with those evaluated by a rotational viscometer.

• Journal of Life Science
• /
• v.28 no.10
• /
• pp.1127-1131
• /
• 2018

Cortisol, a steroid hormone, functions within metabolism, immune response, and stress. Intense or prolonged physical exercise increases cortisol levels to enhance the gluconeogenesis pathway and stabilize blood glucose level. However, cortisol also exerts a negative impact on muscle function and creates a stressful environment in skeletal muscle cells. The present study investigated the function of cortisol as a stress hormone. To examine the effect of the exercise-induced hormone cortisol on skeletal muscles, C2C12 cells were cultured and treated with cortisol at different concentrations. As a result, we found that the morphology of C2C12 changed remarkably with 5 ug/ml cortisol treatment. Western blot analysis was conducted to learn whether ER-stress and autophagy were induced. We found that the expression ratio of LC3I/LC3II decreased and BiP expression increased after cortisol treatment. In addition, immunocytochemistry analysis with IER3 antibody clearly showed that apoptosis is induced after 12-hour cortisol treatment. These results indicate that cortisol treatment could induce apoptosis, ER-stress, and autophagy in muscle cells. This study would provide valuable information in the study of the effects of exercise on skeletal muscle cells and the development of additives to reduce cortisol stress.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.1
• /
• pp.98-105
• /
• 2005

The effects of chlorination on the elimination of three estrogenic chemicals such as $17{\beta}$-estradiol (E2), nonylphenol (NP) and bis-phenol A (BPA) were investigated using yeast two-hybrid assay (YTA), estrogen receptor competition assay (ER-CA), and high-performance liquid chromatography/mass spectrometer (LC/MS). Results of YTA, ECA and the analysis of LC/MS indicated that the estrogenic activity of above mentioned three endocrine disruptors were significantly reduced as the result of chlorination. The decrease in estrogenic activity paralleled with decrease in estrogenic chemicals under the influence of free chlorine. One common characteristic of estrogenic chemicals is the presence of a phenolic ring. Considering that a phenolic ring is likely to undergo some sort of transformation in aqueous chlorination solution, the above mentioned results may be applied to the rest of the other estrogenic chemicals in natural waters.

• Korean Journal of Pharmacognosy
• /
• v.50 no.3
• /
• pp.198-204
• /
• 2019

A facile and convenient method was developed for the mass production of epigallocatechin gallate (EGCG) rich green tea extract (Er-GTE). The Er-GTE was successfully obtained from the crude water extract of green tea by the combination of two step purification, i.e., a simple adsorption process on the cation exchange resins (Trilite SCR-B) followed by the chromatography with Diaion HP-20 resins. The green tea extract produced by water extraction under $45^{\circ}C$ was subjected to adsorb on the strongly acidic cation exchange resin, Trilite SCR-B. The eluate passed through the resin was reabsorbed on Diaion HP-20 resin, which was subjected to elute with a mixture of water and alcohol by conventional chromatographical manner. The EGCG content in Er-GTE was estimated above 97% by HP-LC analysis and the newly developed method was regarded as the most suitable and appropriate process for the mass production of epigallocatechin gallate rich green tea extract (Er-GTE).

• IMMUNE NETWORK
• /
• v.12 no.6
• /
• pp.253-260
• /
• 2012

${\alpha}$-Mangostin is a xanthon derivative contained in the fruit hull of mangosteen (Garcinia mangostana L.), and the administration of ${\alpha}$-Mangostin inhibited the growth of transplanted colon cancer, Her/CT26 cells which expressed Her-2/neu as tumor antigen. Although ${\alpha}$-Mangostin was reported to have inhibitory activity against sarco/endoplasmic reticulum $Ca^{2+}$ ATPase like thapsigargin, it showed different activity for autophagy regulation. In the current study, we found that ${\alpha}$-Mangostin induced autophagy activation in mouse intestinal epithelial cells, as GFP-LC3 transgenic mice were orally administered with 20 mg/kg of ${\alpha}$-Mangostin daily for three days. However, the activation of autophagy by ${\alpha}$-Mangostin did not significantly increase OVA-specific T cell proliferation. As we assessed ER stress by using XBP-1 reporter system and phosphorylation of $eIF2{\alpha}$, thapsigargin-induced ER stress was significantly reduced by ${\alpha}$-Mangostin. However, coadministration of thapsigargin with ${\alpha}$-Mangostin completely blocked the antitumor activity of ${\alpha}$-Mangostin, suggesting ER stress with autophagy blockade accelerated tumor growth in mouse colon cancer model. Thus the antitumor activity of ${\alpha}$-Mangostin can be ascribable to the autophagy activation rather than ER stress induction.

• The Korean Journal of Applied Statistics
• /
• v.31 no.4
• /
• pp.427-446
• /
• 2018

Korea will have a super-aged society within only 30 years according to the United Nations' definition of an aging society and the statistics on Korea's Population projections (2016), indicates that Korea has the fastest ageing speed in the world. There is a lack of data on long-term time-series data on death as related to pension and welfare policies compared to the rapid rate of aging. This paper estimates life expectancy over 245 years (from 1955 to 2200) through past and future forecasts as well as compares the expected life expectancy of the synthetic cohort and the real cohort. In addition, an international comparisons were made to understand the level of aging in Korea. Estimates of the back-projection period were compared with previous studies and the LC model to improve accuracy and objectivity. In addition, the predictions after 2016 reflected the declined mortality rate effect of Korea using the LC-ER model. The results showed an increase in life expectancy of about 30 years over 60 years (1955-2015) with an expected life expectancy of the real cohort over the second century (1955-2155) higher than the synthetic cohort. The comparative advantage of life expectancy of real cohorts was confirmed to be a common trend among comparative countries. In addition, Japan and Korea have a higher life expectancy and starting from 85 to 90 years old, all comparative countries show that the growth rate for the life expectancy of synthetic and real cohorts is less than previous years.

• Journal of Korean Library and Information Science Society
• /
• v.3
• /
• pp.79-88
• /
• 1976

In Ecorea Lrynasty, the authority all officers a compulsary obligatic.~ to learn the Nyo-I~.'z~\ulcorneruzngd er the custody of a super1 iscr o; Letters wino -1 a\ulcorner the ~ejponsible officer to train ci~ril senants. The Nyo-Kjli ilg was possible to interpret the pious love of ci I illans to the~re lders as a mutual ethics between the parental ber~ec;~lc nce and the filial piety of inferiors which n-as far superior to the traditional cthic; that was laid on an firm obligation of inieri~rs to tEei:- elders. The filial piety as a lovc for elders mean2 a mutual harrn~n:a~n d show\ulcorner a berieiolent conduct as an influence of a political morality. Thc heaer-o!erLt conduct was developed as a political morality of Confucius originated from the filial piety of Confucius based on a moral policj . Such a kenerolent conduct is to become a main spring to effect a mutual tie betn-een the king and his people as a national system of the Confucian theory. In i*

• The Korean Journal of Applied Statistics
• /
• v.33 no.4
• /
• pp.421-437
• /
• 2020

This paper implemented a method to predict the fertility rate, mortality rate, and international migration rate using the R program, which has been widely used in recent years, that calculates population projection by substituting the results into the Leslie matrix. In particular, the generalization log gamma model for the fertility rate by Kaneko (2003), LC-ER model for mortality rate by Li et al. (2013), and functional data model for international migration rates proposed by Ramsay and Silverman (2005) and Hyndman and Booth (2008), Hyndman et al. (2013) can be directly demonstrated with R programs. Demography and bayesPop have been introduced as a representative demographic package implemented in R; however, it can be analyzed only for data uploaded to Human Mortality Database (HMD) and Human Fertility Database (HFD) with data changes and modifications requiring application of other data. In particular, in Korea, there is a limitation in applying this package because it is provided only for short-term data in HMD. This paper introduces an R program that can reflect this situation and the different patterns of low fertility, aging, migration of domestic and foreigners in Korea, and derives a population projection for the year 2117.