• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.196-200
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• 1999

A recombinant human $\alpha_{s1}$-casein was expressed as a secretory product in the yeast Saccharomyces cerevisiae. Three different leader sequences derived from the mating factor $\alpha$l (MF$\alpha$l), inulinase, and human $\alpha_{s1}$-casein were used to direct the secretion of human $\alpha_{s1}$-casein into the extracellular medium. Among the three leader sequences tested, the native leader sequence of human $\alpha_{s1}$-casein was found to be the most efficient in the secretory expression of human $\alpha_{s1}$-casein, which implies that the native leader sequence of human $\alpha_{s1}$-casein might be used very efficiently for the secretory production of other heterologous proteins in yeast. The recombinant human $\alpha_{s1}$-casein was proteolytically cleaved as the culture proceeded. Therefore, an attempt was made to produce human $\alpha_{s1}$-casein using a S. cerevisiae mutant in which the YAP3 gene encoding yeast aspartic protease 3 (YAP3) was disrupted. After 72 h of culture, most of the human $\alpha_{s1}$-casein secreted by the wild type was cleaved, whereas more than 70% of the human $\alpha_{s1}$-casein secreted by yap3-disruptant remained intact. The results suggest that YAP3 might be involved in the internal cleavage of human $\alpha_{s1}$-casein expressed in yeast

• Honam Mathematical Journal
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• v.39 no.2
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• pp.297-305
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• 2017

Let ${\alpha}$ > 0 be a real number and $(s_{\alpha}(n))_{n{\geq}1}$ be the lexicographically greatest Sturmian word of slope ${\alpha}$. We investigate Dirichlet series of the form ${\sum}^{\infty}_{n=1}s_{\alpha}(n)n^{-s}$. To do this, a generalization of Euler's totient function is required. For a real ${\alpha}$ > 0 and a positive integer n, an arithmetic function ${\varphi}{\alpha}(n)$ is defined to be the number of positive integers m for which gcd(m, n) = 1 and 0 < m/n < ${\alpha}$. Under a condition Re(s) > 1, this paper establishes an identity ${\sum}^{\infty}_{n=1}s_{\alpha}(n)n^{-S}=1+{\sum}^{\infty}_{n=1}{\varphi}_{\alpha}(n)({\zeta}(s)-{\zeta}(s,1+n^{-1}))n^{-s}$.

• Biomolecules & Therapeutics
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• v.26 no.3
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• pp.268-273
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• 2018

Sleep is the most basic and essential physiological requirement for mental health, and sleep disorders pose potential risks of metabolic and neurodegenerative diseases. Tryptic hydrolysate of ${\alpha}_{S1}$-casein (${\alpha}_{S1}-CH$) has been shown to possess stress relieving and sleep promoting effects. However, the differential effects of ${\alpha}_{S1}-CH$ on electroencephalographic wave patterns and its effects on the protein levels of ${\gamma}$-aminobutyric acid A ($GABA_A$) receptor subtypes in hypothalamic neurons are not well understood. We found ${\alpha}_{S1}-CH$ (120, 240 mg/kg) increased sleep duration in mice and reduced sleep-wake cycle numbers in rats. While ${\alpha}_{S1}-CH$ (300 mg/kg) increased total sleeping time in rats, it significantly decreased wakefulness. In addition, electroencephalographic theta (${\theta}$) power densities were increased whereas alpha (${\alpha}$) power densities were decreased by ${\alpha}_{S1}-CH$ (300 mg/kg) during sleep-wake cycles. Furthermore, protein expressions of $GABA_A$ receptor ${\beta}_1$ subtypes were elevated in rat hypothalamus by ${\alpha}_{S1}-CH$. These results suggest ${\alpha}_{S1}-CH$, through $GABA_A$ receptor modulation, might be useful for treating sleep disorders.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.269-275
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• 1981

The fishing hooks were tested for breaking and unbending due to plastic deformation of the material. Study of tensile test is not complicated, but has not even worked out fully enough, especially when the test specimen is subjected to plastic deformation. The fishing hook is subjected to unbending stress and the critical section is a Point which is furthest from the line of action of the forces. The dynamic force of fish during jerks depends on their speed of movement and body weight, the kinetic energy corresponding to it and also on the rlastic displacement of the rigging which absorb the energy. Six kinds of hook were tested by the dynamometer under tensile speed 290mm/min (subscript s) and 780mm/min (subscript f). According to their results, the breaking load(B: kg) can be induced with the formula $B={\alpha}wd^2+\beta$ where w(mm) is the distance between the barb base and the lower shank and d(mm) is diameter. The coefficients of the formula for the round hooks(R) and the angular hooks(A) are approximately as follows: $$R:\;\alpha_{s}=0.5,\;\beta_{s}=1.6,\;\alpha_{f}=0.4,\;\beta_{f}=1.4$$ $$A:\;\alpha_{s}=1.1,\;\beta_{s}=2.0,\;\alpha_{f}=1.0,\;\beta_{f}=0.9$$ The ratio of $B_{f}\;to\;B_{s}$ is corresponding to 0.8. The ratio of deformation(X) that is moved distance of barb base at break to the distance(H) between head base and barb base is about $50\%$. Further study should be carried out on the subject of impact and fatigue test under the same condition which is exerted force by the hooked fish.

• Journal of the Korean Mathematical Society
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• v.56 no.4
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• pp.1049-1061
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• 2019

For ${\alpha}{\geq}1$, let $s_{\alpha}(n)={\lceil}{\alpha}n{\rceil}-{\lceil}{\alpha}(n-1){\rceil}$. A continued fraction $C({\alpha})=[0;s_{\alpha}(1),s_{\alpha}(2),{\ldots}]$ is considered and analyzed. Appealing to Diophantine approximation, we investigate the differentiability of $C({\alpha})$, and then show its singularity.

• Journal of the Korean Mathematical Society
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• v.41 no.1
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• pp.209-229
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• 2004

Let $\Sigma_{$\mid$\alpha$\mid$=m}\;s_{\alpha}z^{\alpha},\;z\;{\in}\;{\mathbb{C}}^n$ be a unimodular m-homogeneous polynomial in n variables (i.e. $$\mid$s_{\alpha}$\mid$\;=\;1$ for all multi indices $\alpha$), and let $R\;{\subset}\;{\mathbb{C}}^n$ be a (bounded complete) Reinhardt domain. We give lower bounds for the maximum modules $sup_{z\;{\in}\;R\;$\mid$\Sigma_{$\mid$\alpha$\mid$=m}\;s_{\alpha}z^{\alpha}$\mid$$, and upper estimates for the average of these maximum moduli taken over all possible m-homogeneous Bernoulli polynomials (i.e. $s_{\alpha}\;=\;{\pm}1$ for all multi indices $\alpha$). Examples show that for a fixed degree m our estimates, for rather large classes of domains R, are asymptotically optimal in the dimension n.

• East Asian mathematical journal
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• v.21 no.1
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• pp.61-64
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• 2005

Let R be a commutative ring with identity, and let $f,\;g_i(i=1,\;\ldots,\;n),\;g_{\alpha}(\alpha{\in}S)$ be elements of R. We show that the following statements are equivalent; (i) $X_f{\subseteq}{\cup}_{\alpha{\in}S}X_{g\alpha}$ only if $X_f{\subseteq}X_{g\alpha}$ for some $\alpha{\in}S$, (ii) $V(f){\subseteq}{\cup}_{\alpha{\in}S}V(g_{\alpha})$ only if $V(f){\subseteq}V(g_{\alpha})$ for some $\alpha{\in}S$, (iii) $V(f){\subseteq}{\cup}^n_{i=1}V(g_i)$ only if $V(f){\subseteq}V(g_i)$ for some i, (iv) Spec(R) is linearly ordered under inclusion.

• Journal of the Korea Society of Computer and Information
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• v.20 no.8
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• pp.29-33
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• 2015

This paper proposes a discrete logarithm algorithm that remarkably reduces the execution time of Pollard's Rho algorithm. Pollard's Rho algorithm computes congruence or collision of ${\alpha}^a{\beta}^b{\equiv}{\alpha}^A{\beta}^B$ (modp) from the initial value a = b = 0, only to derive ${\gamma}$ from $(a+b{\gamma})=(A+B{\gamma})$, ${\gamma}(B-b)=(a-A)$. The basic Pollard's Rho algorithm computes $x_i=(x_{i-1})^2,{\alpha}x_{i-1},{\beta}x_{i-1}$ given ${\alpha}^a{\beta}^b{\equiv}x$(modp), and the general algorithm computes $x_i=(x_{i-1})^2$, $Mx_{i-1}$, $Nx_{i-1}$ for randomly selected $M={\alpha}^m$, $N={\beta}^n$. This paper proposes 4-model Pollard Rho algorithm that seeks ${\beta}_{\gamma}={\alpha}^{\gamma},{\beta}_{\gamma}={\alpha}^{(p-1)/2+{\gamma}}$, and ${\beta}_{{\gamma}^{-1}}={\alpha}^{(p-1)-{\gamma}}$) from $m=n={\lceil}{\sqrt{n}{\rceil}$, (a,b) = (0,0), (1,1). The proposed algorithm has proven to improve the performance of the (0,0)-basic Pollard's Rho algorithm by 71.70%.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.487-493
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• 2018

Cluster of differentiation 44 (CD44), a cell surface receptor for hyaluronic acid (HA), is involved in aggressive cancer phenotypes. Herein, we investigated the role of the CD44 standard isoform (CD44s) in hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) regulation using MCF7 overexpressing CD44s (pCD44s-MCF7). When pCD44s-MCF7 was incubated under hypoxia, levels of $HIF-1{\alpha}$, vascular endothelial growth factor, and the $HIF-1{\alpha}$ response element-derived luciferase activity were significantly increased compared to those in the control MCF7. Incubation of pCD44s-MCF7 cells with HA further increased $HIF-1{\alpha}$ accumulation, and the silencing of CD44s attenuated $HIF-1{\alpha}$ elevation, which verifies the role of CD44s in $HIF-1{\alpha}$ regulation. In addition, the levels of phosphorylated extracellular signal-regulated kinase (ERK) was higher in hypoxic pCD44s-MCF7 cells, and $HIF-1{\alpha}$ accumulation was diminished by the pharmacological inhibitors of ERK. CD44s-mediated $HIF-1{\alpha}$ augmentation resulted in two functional outcomes. First, pCD44s-MCF7 cells showed facilitated cell motility under hypoxia via the upregulation of proteins associated with epithelial-mesenchymal transition, such as SNAIL1 and ZEB1. Second, pCD44s-MCF7 cells exhibited higher levels of glycolytic proteins, such as glucose transporter-1, and produced higher levels of lactate under hypoxa. As a consequence of the enhanced glycolytic adaptation to hypoxia, pCD44s-MCF7 cells exhibited a higher rate of cell survival under hypoxia than that of the control MCF7, and glucose deprivation abolished these differential responses of the two cell lines. Taken together, these results suggest that CD44s activates hypoxia-inducible $HIF-1{\alpha}$ signaling via ERK pathway, and the $CD44s-ERK-HIF-1{\alpha}$ pathway is involved in facilitated cancer cell viability and motility under hypoxic conditions.

• Communications of the Korean Mathematical Society
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• v.10 no.4
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• pp.875-880
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• 1995

Let $S_p(\alpha)$ denote the class of the Spirallike functions of order $\alpha, 0 < $\mid$\alpha$\mid$ < \frac{\pi}{2}$ Let $\Pi_N$ denote the subset of $S_p(\alpha)$ consisting of all products $z\Pi^N_{j=1}(1-u_j z)^{-mt_j}$ where $m = 1 + e^{-2i\alpha},$\mid$u_j$\mid$ = 1, t_j > 0$ for $j = 1, \cdots, N$ and $\sum^{N}_{j=1}{t_j = 1}$. In this paper we prove that extreme points of $S_p(\alpha)$ may be found which lie in $\Pi_N$ for some $N \geq 2$. We are let to conjecture that all exreme points of $S_p(\alpha)$ lie in $\Pi_N$ for somer $N \geq 1$ and that every such function is an extreme point.