• Journal of Microbiology and Biotechnology
• /
• v.17 no.6
• /
• pp.1045-1048
• /
• 2007

Two genes, dps encoding decaprenyl diphosphate synthase and dxs encoding 1-deoxy-D-xylulose 5-phosphate synthase, were isolated from Rhizobium radiobacter ATCC 4718. DNA sequencing analysis of the dps and dxs genes revealed an open reading frame of 1,077 bp and 1,920 bp, respectively. The heterologous expression in Escherichia coli BL21(DE3) was carried out in order to identify their functions. Recombinant E. coli BL21(DE3) harboring the dps gene produced $CoQ_{10}$ as well as $CoQ_8$ and $CoQ_9$, whereas E. coli harboring only the dxs gene produced more $CoQ_8$ compared with the wild-type E. coli. Additionally, the coexpression of dps and dxs genes in E. coli was carried out. The recombinant E. coli harboring only the dps gene produced $0.21{\pm}0.04\;mg/l$ of $CoQ_{10}$, whereas the coexpressed E. coli with dps and dxs genes produced $0.37{\pm}0.07\;mg/l$ of $CoQ_{10}$. HPLC analysis also showed that the $CoQ_{10}$ fraction (100% of the total CoQs distribution) was increased from $15.86{\pm}0.66%$ (only dps) to $29.78{\pm}1.80%$ (dps and dxs).

• Journal of Forest and Environmental Science
• /
• v.8 no.1
• /
• pp.51-66
• /
• 1992

This study was carried out to investigate the micromorphology of vessel wall sculpture such as shape of perforation plate, perforation rim, steepness of perforation plate, occurrence of vestured pit, warty layer and ray-vessel pitting on 13 species of Fagaceae in Korea. The results were summarized as follows ; 1. In the species examined, all sample species except Fagus crenata var. multinervis have simple perforation plate. But Fagus crenata var. multinervis has simple and scalariform perforation plate (it was called to combination perforation plate) in a tree stem. 2. The shapes of perforation rim could be classified into five types; Type A without tail, Type B with small tail on both sides, Type C with long tail on both sides, Type D with tail only one side and Type E with the very short interval between perforations. Among five types, Type Band C have higer frequency of distribution than the others. 3. The steepness of perforation plate measured was about 20 degree on pore zone and 43 degree on outside parts of pore zone. 4. Species with vestured pit were Q. aliena, Q, dentata, Q. variabilis, Fagus crenata var. multinervis, Castanopsis cuspidata var sieboldii, Q. acuta, Q. stenophylla, and Q. glauca. But the extent of vesturing was very slight and vestured pits were observed mainly in ray-vessel pit of some vessel elements. 5. Species with warty layer on the inner surface wall of all vessel elements were Q. acuta, Q. stenophylla, Q. glauca, Fagus crenata var. multinervis and species with warty layer of some vessel elements were Q. aliena, Q, dentata, Q. variabilis, Castanopsis cuspidata var. sieboldii. 6. Species with palisade ray-vessel pit were Q. acuta, Q. stenophylla, Q. glauca, Castanea crenata, Castanea bungeana, Q. aliena, Q. serrata, Q. mongolica, and species with scalariform ray-vessel pit was Fagus crenata var. multinervis and species with oval ray-vessel pit were Q, dentata, Castanopsis cuspidata var sieboldii.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.529-531
• /
• 2011

In Gen-2 Q-algorithm, the values of weight C, which is the parameter for incrementing or decrementing the slot-count size, are not defined in the standard. In this case, if the reader selects an inappropriate weight, there are a lot of empty or collided slots. As a result, the performance will be degraded because the frame size does not converge to the optimal point quickly during the query round. In this paper, we analyze how the performances of Gen-2 Q-algorithm will be affected by the weight value.

• Korean Journal of Mathematics
• /
• v.25 no.3
• /
• pp.349-358
• /
• 2017

The cyclic group $C_n={\langle}(12{\cdots}n){\rangle}$ acts on the set $(^{[n]}_k)$ of all k-subsets of [n]. In this action of $C_n$ the number of orbits of size d, for d | n, is $$O^{n,k}_d={\frac{1}{d}}{\sum\limits_{{\frac{n}{d}}{\mid}s{\mid}n}}{\mu}({\frac{ds}{n}})(^{n/s}_{k/s})$$. Stanton and White [6] generalized the above identity to construct the orbit polynomials $$O^{n,k}_d(q)={\frac{1}{[d]_{q^{n/d}}}}{\sum\limits_{{\frac{n}{d}}{\mid}s{\mid}n}}{\mu}({\frac{ds}{n}})[^{n/s}_{k/s}]_{q^s}$$ and conjectured that $O^{n,k}_d(q)$ have non-negative coefficients. In this paper we give a constructive proof for the positivity of coefficients of the orbit polynomial $O^{n,2}_d(q)$.

• Journal of Korean Society for Quality Management
• /
• v.33 no.2
• /
• pp.40-50
• /
• 2005

HoQ (House of Quality) provides an effective tool not only to arrange and evaluate VoC (Voice of Customers) and VoE (Voice of Engineers), but also to link and combine VoC and VoE, thereby presenting explicit directions for quality improvement. There have been, however, few researches on the HoQ framework in the IT industry. The case study discussed here serves an illustration of the applicability and usefulness of the HoQ approach to website quality improvement. The proposed HoQ framework shows great potentials since customers needs are explicitly considered in the framework, and it helps website administrators develop better web services by providing guidelines for reengineering the website operations.

• Journal of applied mathematics & informatics
• /
• v.33 no.5_6
• /
• pp.649-656
• /
• 2015

In this paper we investigate some symmetric property of the twisted q-Euler zeta functions and twisted q-Euler polynomials.

• Journal of Veterinary Clinics
• /
• v.26 no.5
• /
• pp.413-418
• /
• 2009

This study was performed to investigate the changes of the serological parameters of the rats fed a high fat and high cholesterol diets with or without quercetin supplement for five weeks. Thirty Sprague-Dawley male rats ($152.1{\pm}17.0\;g$ of body weight) were randomly divided into three groups with 10 rats in each group. Rats in the control(C) group were fed the high fat and high cholesterol diet containing 15% lard, 2% cholesterol and 0.5% sodium cholate (w/w). Rats in two treatment groups were fed the same diet supplemented with 0.25% quercetin (Q-0.25) or 0.5% quercetin (Q-0.5) on the weight to weight basis, respectively. The final body weight, gain of body weight, the amount of feed intake and the feed efficiency of rats in between control and treatment groups were not significantly different. Serum glucose, total protein, albumin, globulin and albumin/globulin (A/G) ratio of rats showed no significant differences between control and treatment groups. Serum total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and atherogenic index(AI) of rats in both Q-0.25 and Q-0.5 groups were significantly lower than in C group (p < 0.05). However serum high density lipoprotein-cholesterol (HDL-C) was significantly higher in both Q-0.25 and Q-0.5 groups than in C group (p < 0.05). The levels of triglyceride in sera of rats showed no significant differences between control and treatment groups. The values of AST and ALT in sera of rats showed no significant differences between control and treatment groups. Therefore the supplementation of quercetin to high fat and high cholesterol diet in rats was effective in reducing the levels of serum lipids to cause cardiovascular diseases and in elevating the level of HDL-C to protect cardiovascular diseases.

• Bulletin of the Korean Mathematical Society
• /
• v.47 no.6
• /
• pp.1181-1188
• /
• 2010

q-Volkenborn integrals ([8]) and fermionic invariant q-integrals ([12]) are introduced by T. Kim. By using these integrals, Euler q-zeta functions are introduced by T. Kim ([18]). Then, by using the Euler q-zeta functions, S.-H. Rim, S. J. Lee, E. J. Moon, and J. H. Jin ([25]) studied q-Genocchi zeta functions. And also Y. H. Kim, W. Kim, and C. S. Ryoo ([7]) investigated twisted q-zeta functions and their applications. In this paper, we consider the q-analogue of twisted Lerch type Euler zeta functions defined by $${\varsigma}E,q,\varepsilon(s)=[2]q \sum\limits_{n=0}^\infty\frac{(-1)^n\epsilon^nq^{sn}}{[n]_q}$$ where 0 < q < 1, $\mathfrak{R}$(s) > 1, $\varepsilon{\in}T_p$, which are compared with Euler q-zeta functions in the reference ([18]). Furthermore, we give the q-extensions of the above twisted Lerch type Euler zeta functions at negative integers which interpolate twisted q-Euler polynomials.

• Korean Journal of Microbiology
• /
• v.46 no.1
• /
• pp.46-51
• /
• 2010

Coenzyme Q10 (CoQ10) is an essential lipid-soluble component of membrane-bound electron transport chains. CoQ10 is involved in several aspects of cellular metabolism and is increasingly being used in therapeutic applications for several diseases. Despite the recent accomplishments in metabolic engineering of Escherichia coli for CoQ10 production, the production levels are not yet competitive with those by fermentation or isolation. So we tested several microorganisms obtained from the KCTC of Biological Resource Center to find novel sources of strain-development for CoQ10-production. Then we selected two strains, Paracoccus denitrificans (KCTC 2530) and Asaia siamensis (KCTC 12914), and tested to optimize the CoQ10 production conditions. Among the carbon sources tested, CoQ10 production was the highest when fructose was supplied about 4% concentration. Yeast extract produced the highest CoQ10 production about 2% concentration. The highest CoQ10 production was obtained at pH 6.0 for P. denitrificans and pH 8.0 for A. siamensis. And two strains showed the highest CoQ10 production at $30^{\circ}C$, but the highest DCW was obtained at $37^{\circ}C$. In the fed-batch culture, P. denitrificans yielded $14.34{\pm}0.473$ mg and A. siamensis yielded $12.53{\pm}0.231$ mg of final CoQ10 production.

• Journal of applied mathematics & informatics
• /
• v.41 no.1
• /
• pp.167-179
• /
• 2023

In this paper, we investigate solutions of equations which are linear (p, q)-difference equation of higher order by using (p, q)-derivative and integral. We also derive the solution of equation in the case of second order.