• Honam Mathematical Journal
• /
• v.26 no.4
• /
• pp.463-469
• /
• 2004

In this paper we establish some recurrence relations satisfied by quotient moments of upper record values from the exponential distribution. Let $\{X_n,\;n{\geq}1\}$ be a sequence of independent and identically distributed random variables with a common continuous distribution function F(x) and probability density function(pdf) f(x). Let $Y_n=max\{X_1,\;X_2,\;{\cdots},\;X_n\}$ for $n{\geq}1$. We say $X_j$ is an upper record value of $\{X_n,\;n{\geq}1\}$, if $Y_j>Y_{j-1}$, j > 1. The indices at which the upper record values occur are given by the record times {u(n)}, $n{\geq}1$, where u(n)=min\{j{\mid}j>u(n-1),\;X_j>X_{u(n-1)},\;n{\geq}2\} and u(1) = 1. Suppose $X{\in}Exp(1)$. Then $\Large{E\;\left.{\frac{X^r_{u(m)}}{X^{s+1}_{u(n)}}}\right)=\frac{1}{s}E\;\left.{\frac{X^r_{u(m)}}{X^s_{u(n-1)}}}\right)-\frac{1}{s}E\;\left.{\frac{X^r_{u(m)}}{X^s_{u(n)}}}\right)}$ and $\Large{E\;\left.{\frac{X^{r+1}_{u(m)}}{X^s_{u(n)}}}\right)=\frac{1}{(r+2)}E\;\left.{\frac{X^{r+2}_{u(m)}}{X^s_{u(n-1)}}}\right)-\frac{1}{(r+2)}E\;\left.{\frac{X^{r+2}_{u(m-1)}}{X^s_{u(n-1)}}}\right)}$.

• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.3
• /
• pp.265-271
• /
• 1997

The salt accumulation, and chemical properties of 90 samples of the plastic film house soil in the area of Cheongju and Chungju were surveyed. Soil textural distribution of soil samples was 30% for sandy loam, 27% for loam and 43% for silty loam. Percentage distribution of electrical conductivity(EC) of surface soil was 23% below $2dS\;m^{-1}$, 30% for $2{\sim}4dS\;m^{-1}$, 25% for $4{\sim}6dS\;m^{-1}$ and 22% over $6dS\;m^{-1}$. Salt affected soil, which EC was higher than $4dS\;m^{-1}$, covered nearly 50% of all field surveyed. However subsoils(20~30cm) below $2dS\;m^{-1}$ was 68%. Salts in plastic film house soil was accumulated by increasing the cultivation period. After 5 years of cultivation electrical conductivity in plastic house soil was generally higher than $4.47dS\;m^{-1}$ in EC that was 2.8~5.6 times higher than that in the field soil in the outside of plastic film house. As the result of temporary removal of plastic film cover from the house during the rainy summer season, salt content in soil was decreased from $3.54{\sim}7.36dS\;m^{-1}$ to $0.71{\sim}2.92dS\;m^{-1}$ in EC due to the desalinization by runoff and percolating water. Contents of $NO_3-N$, $SO_4-S$ and Cl in plastic film house soil were 2.5. 7.0 and 3.4 times higher than those of open field respectively.

• Animal cells and systems
• /
• v.16 no.5
• /
• pp.415-424
• /
• 2012

Four species of ophichthid leptocephali were identified using 12S rDNA sequences, and their morphological descriptions were first provided based on six individuals (S1-S3,M1, and E1-E2) collected from the East Sea and the Korea Strait between September 2008 and October 2010. Mitochondrial 12S rDNA 859-861 base pairs of ophichthid leptocephali were compared with those of 16 ophichthids adult and 2 outgroups (Anguilla japonica and Conger myriaster). Leptocephali of S1 and E1 were very closely clustered with adult of Scolecenchelys borealis (D=0.002) and Echelus uropterus (D=0.000), respectively. However, leptocephali of S2-S3 andM1 were slightly far clustered with leptocephalus of S1 (D=0.006) and adult of Muraenichthys gymnopterus (0.034), respectively. We believe that S1 and E1 are S. borealis and E. uropterus, respectively, in which the former is unrecorded species in Korea. However, S2-S3 and M1 may be undescribed species belonging to genus Scolecenchelys and Muraenichthys, respectively, because total numbers of myomeres for S2-S3 (148-158) and M1 (151) were not consistent with total numbers of vertebrae or distribution for any adult of Scolecenchelys spp. and Muraenichthys spp. in the world. We propose the new Korean name 'Dong-hae-mul-baem' for S. borealis.

• Applied Biological Chemistry
• /
• v.32 no.3
• /
• pp.295-302
• /
• 1989

This study was carried out as a preliminary test to investigate the improvement of soysauce and soybean paste for natural food. The soybean was treated on raw, soaked, roasted, and steamed condition and it was maked that rice koji was inoculated by Asp. oryzae, Asp. niger, Asp. awamori and on natural condition fermented. They were maked raw soybean-soypaste $(S_0)$, soaked soybean-soypaste $(S_1)$, roasted soybean-soypaste $(S_2)$, and steamed soybean-soypaste $(S_3)$ from soybean (60%), rice koji (30%) and salt (10%) respectively in order to investigate the changes of enzymes activity(amylase, protease, lipase and lipoxygenase activity) during fermentation of them. The results obtained were summarized as follows; Amylase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_2>S_3$ in the soybean treatments. Protease activity was in the order of natural fermented microorganisms>Asp. niger>Asp. oryzae>Asp. awamori in the microorganisms, and $S_3>S_2>S_1>S_0$ in the soybean treatments. Lipase activity was a similar tendency in the microorganisms, but it was in the order of $S_0>S_1>S_3>S_2$ in the soybean treatments. Lipoxygenase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_3>S_2$ in the treatments.

• Development and Reproduction
• /
• v.12 no.1
• /
• pp.57-66
• /
• 2008

Changes in luteinizing hormone (LH), serum testosterone (T), and salivary T levels with age were examined in Korean men. Serum was obtained from 167 Korean men of different ages ($20{\sim}69\;y$), and the serum LH and T levels were measured. Saliva samples were also obtained, and the salivary T level was determined. The LH levels did not change considerably until 40 y of age (20s, $2.5{\pm}1.0$; 30s, $2.7{\pm}1.5$; and 40s, $2.5{\pm}1.8\;mIU/mL$) but increased significantly around 50 y (50s, $3.7{\pm}1.8$ and 60s, $3.1{\pm}1.7\;mIU/mL$). Further, the serum T levels also did not change until 40 y of age (20s, $5.3{\pm}2.6$, 30s, $4.4{\pm}1.4$, 40s, $4.1{\pm}1.5\;ng/mL$) but decreased significantly at 50 y (50s, $3.4{\pm}1.5$; 60s, $2.6{\pm}0.8\;ng/mL$). The salivary T levels also showed small changes until the age of 40 y ($20s{\sim}40s$, $0.11{\pm}0.015\;ng/mL$) but decreased significantly at 50 y ($0.08{\pm}0.03\;ng/mL$). Thus, the relative ratio of salivary T to serum T levels did not change significantly in all the ages examined ($2.4{\pm}0.9%$). Linear regression analysis predicted that the LH levels increased 1.5%/y while the serum and salivary T levels decreased 1%/y and 0.8%/y, respectively. The serum T/LH ratio did not change considerably until the age of 40 y ($20s{\sim}40s$, $2.27{\pm}0.14$) but decreased significantly ($1.2{\pm}1.0$) at 50 y. Age-related changes in the salivary T/LH ratio were very similar to those in the serum T/LH ratio. These results demonstrated that LH and T levels in serum or saliva did not change considerably until 40 y of age; instead, in Korean men, from 50 y of age, the LH level increased, while the T level decreased. This suggests that primary testicular failure that occurred due to aging (approximately 50 y) and caused this phenomenon. The present study also shows that the salivary T level can be an indicator of the free T level in serum although the salivary T level correlates weakly with the total T level in serum (r=0.53). Thus, information regarding salivary T levels may be useful for studying the age-related changes occurring in male testicular physiology.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.495-500
• /
• 2001

Seed germination, seedling growth, plant establishment after transplanting, set of female flowers, and subsequent fruit growth were examined in cucumbers grown in soils having varying electrical conductivities (EC) of $1.0-5.0dS{\cdot}m^{-1}$ adjusted by adding different amount of a commercial compound fertilizer (N : $P_2O_5$ : $K_2O$ = 21 : 17 : 17). Slower seed germination was recorded in soils having EC value of $3.0dS{\cdot}m^{-1}$ or higher and little or no germination took place in soils with EC $4.0dS{\cdot}m^{-1}$ until 8 days after sowing. Suppression of seedling growth was apparent in soils having EC level of $2.5dS{\cdot}m^{-1}$. All seedlings died eventually at EC level of $3.5dS{\cdot}m^{-1}$. Leaf color became progressively dark green with the increase in EC from 1.0 to $3.0dS{\cdot}m^{-1}$. The first female flower was formed at higher node and the number of days required for the first flowering of female flower increased with the increase in EC values up to $3.0dS{\cdot}m^{-1}$. Occasionally, leaf yellowing and self-topping symptoms appeared in plants grown in soils having EC level of $3.0dS{\cdot}m^{-1}$.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.1
• /
• pp.58-64
• /
• 2013

The objective of this study was to understand the physiological response and cadmium accumulation of MuS1 transgenic tobacco exposed to high concentration of Cd in soil. For this, a pot experiment was carried out in a greenhouse for a month, with two lines of MuS1 transgenic tobaccos (S4 and S6) and non-transgenic tobacco cultivated in the soils spiked at three different Cd concentrations (0, 60 and 180 mg $kg^{-1}$). Both transgenic and non-transgenic tobacco showed visible toxic symptoms such as chlorosis and leaf roll as treated concentration increased. The net photosynthetic rates of MuS1 plants (S4 and S6) exposed at 180 mg $kg^{-1}$ Cd were 6.3 and $7.7{\mu}mol\;m^{-2}s^{-1}$, being higher than those of the non-transgenic plant ($4.8{\mu}mol\;m^{-2}s^{-1}$). Values of stomatal conductance of MuS1 transgenic plants (0.05 and 0.008 mmol $H_2O\;m^{-2}s^{-1}$) were also higher than those of non-transgenic plant (0.03 mmol $H_2O\;m^{-2}s^{-1}$). In addition, fresh and dry weights of MuS1 transgenic plants were heavier than those of non-transgenic plant. Likewise, MuS1 transgenic plants appeared to be better physiological performance than non-transgenic tobacco when exposed at high concentration of Cd in soil. With regard to metal accumulation, MuS1 transgenic tobaccos accumulated more Cd in their roots than non-transgenic tobacco implying that MuS1 transgenic tobacco is suggested to be used for phytostabilization of heavy metals.

• Biomolecules & Therapeutics
• /
• v.27 no.3
• /
• pp.318-326
• /
• 2019

Sphingosine 1-phosphate (S1P) levels are often found to be elevated in serum, bronchoalveolar lavage, and lung tissue of idiopathic pulmonary fibrosis patients and experimental mouse models. Although the roles of sphingosine kinase 1 and S1P receptors have been implicated in fibrosis, the underlying mechanism of fibrosis via Sphingosine 1-phosphate receptor 2 ($S1P_2$) has not been fully investigated. Therefore, in this study, the roles of $S1P_2$ in lung inflammation and fibrosis was investigated by means of a bleomycin-induced lung fibrosis model and lung epithelial cells. Bleomycin was found to induce lung inflammation on day 7 and fibrosis on day 28 of treatment. On the $7^{th}$ day after bleomycin administration, $S1P_2$ deficient mice exhibited significantly less pulmonary inflammation, including cell infiltration and pro-inflammatory cytokine induction, than the wild type mice. On the $28^{th}$ day after bleomycin treatment, severe inflammation and fibrosis were observed in lung tissues from wild type mice, while lung tissues from $S1P_2$ deficient mice showed less inflammation and fibrosis. Increase in TGF-${\beta}1$-induced extracellular matrix accumulation and epithelial-mesenchymal transition were inhibited by JTE-013, a $S1P_2$ antagonist, in A549 lung epithelial cells. Taken together, pro-inflammatory and pro-fibrotic functions of $S1P_2$ were elucidated using a bleomycin-induced fibrosis model. Notably, $S1P_2$ was found to mediate epithelial-mesenchymal transition in fibrotic responses. Therefore, the results of this study indicate that $S1P_2$ could be a promising therapeutic target for the treatment of pulmonary fibrosis.

• Journal of Gastric Cancer
• /
• v.21 no.1
• /
• pp.30-37
• /
• 2021

Purpose: While the amylase concentration of the drainage fluid (dAmy) has been reported to be a predictor of postoperative pancreas-related complications (PPRC), the optimal timing for its measurement has not been fully investigated. Materials and Methods: The clinicopathological data of 387 patients who underwent elective gastrectomy for gastric cancer were reviewed. Laboratory data, including dAmy on postoperative days 1 (dAmy1) and 3 (dAmy3), and serum C-reactive protein (sCRP) concentrations on postoperative days 1 (sCRP1) and 3 (sCRP3) were compared between patients with PPRC and without PPRC. Results: Nineteen of the 387 patients (4.9%) developed PPRC. The optimal cutoff values of dAmy1, dAmy3, sCRP1, and sCRP3 were 1514 IU/L, 761 IU/L, 8.32 mg/dL, and 15.15 mg/dL, respectively. The area under the curve of dAmy1 was greater than that of dAmy3 (0.915 vs. 0.826), and that of sCRP3 was greater than that of sCRP1 (0.820 vs. 0.659). In the multivariate analysis, dAmy1 (P<0.001) and sCRP3 (P=0.004) were significant predictors of PPRC, while dAmy3 (P=0.069) and sCRP1 (P=0.831) were not. Thirteen (41.9%) of 31 patients with both dAmy1 ≥1,545 IU/L and sCRP3 ≥15.15 mg/dL had PPRC ≥Clavien-Dindo II. In contrast, among 260 patients with both dAmy1 <1,545 IU/L and sCRP3 <15.15 mg/dL, none developed PPRC. Conclusions: dAmy1 was more useful than dAmy3 in predicting PPRC. The combination of dAmy1 and sCRP3 may be a useful criterion for the removal of drains on postoperative day 3.

• KSBB Journal
• /
• v.11 no.2
• /
• pp.173-180
• /
• 1996

The contamination of the environment by heavy metals results in a serious public health problem due to the toxicity of those pollutants even at low concentrations. Microorganisms may be used to remediate wastewaters contamlialtd with heavy metals. The waste S. cerevisiae is an inexpensive readily available source of biomass for bioremediation of wastewater. S. cerevisiae was investigated for their ability to absorb Pb. The crushed biomass of S. cerevisiae exhibited higher Pb uptake capacity than the living S. cerevisiae and the sterilized S. cerevisiae. At the same metal concentration, metal uptake per unit concentration or adsorbent decreased when the biomass concentration rises. The order of the biosorption capacity of the living S. cerevisiae was Pb>Cu>Cd=Co>Cr. When S. cerevisiae was pretreated with 0.1 M NaOH, Pb uptake was increased by 150 percent and 0.1 M HC1, 0.1 M $H_2S_O4$ solutions were efficient in the desorption of Pb. The sorption equilibrium of Pb ions can be described by the Freundlich and Langmuir models.