• Journal of Microbiology and Biotechnology
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• 제17권3호
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• pp.496-510
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• 2007

This paper describes the use of a discrete mathematical model to represent the basic mechanisms of regulation of the bacteria E. coli in batch fermentation. The specific phenomena studied were the changes in metabolism and genetic regulation when the bacteria use three different carbon substrates (glucose, glycerol, and acetate). The model correctly predicts the behavior of E. coli vis-a-vis substrate mixtures. In a mixture of glucose, glycerol, and acetate, it prefers glucose, then glycerol, and finally acetate. The model included 67 nodes; 28 were genes, 20 enzymes, and 19 regulators/biochemical compounds. The model represents both the genetic regulation and metabolic networks in an integrated form, which is how they function biologically. This is one of the first attempts to include both of these networks in one model. Previously, discrete mathematical models were used only to describe genetic regulation networks. The study of the network dynamics generated 8 $(2^3)$ fixed points, one for each nutrient configuration (substrate mixture) in the medium. The fixed points of the discrete model reflect the phenotypes described. Gene expression and the patterns of the metabolic fluxes generated are described accurately. The activation of the gene regulation network depends basically on the presence of glucose and glycerol. The model predicts the behavior when mixed carbon sources are utilized as well as when there is no carbon source present. Fictitious jokers (Joker1, Joker2, and Repressor SdhC) had to be created to control 12 genes whose regulation mechanism is unknown, since glycerol and glucose do not act directly on the genes. The approach presented in this paper is particularly useful to investigate potential unknown gene regulation mechanisms; such a novel approach can also be used to describe other gene regulation situations such as the comparison between non-recombinant and recombinant yeast strain, producing recombinant proteins, presently under investigation in our group.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7337-7341
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• 2014

Background: The physiological role of vitamin D extends beyond bone health and calcium-phosphate homeostasis to effects on cancer risk, mainly for colorectal cancer. Vitamin D may have an anticancer effect in colorectal cancer mediated by binding of the active form $1,25(OH)_2D$ to the vitamin D receptor (VDR). The Taq1 VDR gene polymorphism, a C-to-T base substitution (rs731236) in exon 9 may influence its expression and function. The aim of this study wass to determine the 25(OH)D vitamin D level and to investigate the association between circulating vitamin D level and Taq1VDR gene polymorphism among Jordanian colorectal cancer patients. Materials and Methods: This case control study enrolled ninety-three patients and one hundred and two healthy Jordanian volunteers from AL-Basheer Hospital/Amman (2012-2013). Ethical approval and signed consent forms were obtained from all participants before sample collection. 25(OH)D levels were determined by competitive immunoassay Elecsys (Roche Diagnostic, France). DNA was extracted (Promega, USA) and amplified by PCR followed by VDR Taq1 restriction enzyme digestion. The genotype distribution was evaluated by paired t-test and chi-square. Comparison between vitamin D levels among CRC and control were assessed by odds ratio with 95% confidence interval. Results: The vitamin D serum level was significantly lower among colorectal cancer patients (8.34 ng/ml) compared to the healthy control group (21.02ng/ml). Patients deficient in vitamin D (less than 10.0 ng/ml) had increased colorectal cancer risk 19.2 fold compared to control. Only 2.2% of CRC patients had optimal vitamin D compared to 23.5% among healthy control. TT, Tt and tt Taq1 genotype frequencies among CRC cases was 35.5%, 50.5% and 14% compared to 43.1%, 41.2% and 15.7% among healthy control; respectively. CRC patients had lower mean vitamin D level among TT ($8.91{\pm}4.31$) and Tt ($9.15{\pm}5.25$) genotypes compared to control ($21.3{\pm}8.31$) and ($19.3{\pm}7.68$); respectively. Conclusions: There is significant association between low 25(OH)D serum level and colorectal cancer risk. The VDRTaq1 polymorphism was associated with increased colorectal cancer risk among patient with VDRTaq1 TT and Tt genotypes. Understanding the functional mechanism of VDRTaq1 TT and Tt may provide a strategy for colorectal cancer prevention and treatment.

• 한국의상디자인학회지
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• 제4권2호
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• pp.139-161
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• 2002

This study investigates the characteristics of Nordic sweaters works from a historical perspective. Specifically, this study deals with the following research topics: 1) development of Nordic sweaters, 2) the characteristics of Nordic sweaters industry according to the change of times, 3) the comparison of local knitting patterns, 4) the symbolic meaning of the designs in the Nordic sweaters and patterns. The results of the study are summarized as follows. 1. Knitted work developed mostly in Northern Europe, a cold area, and the barren, mountainous coastal areas where people frequently used woolen materials for clothes. It was also developed in Scandinavian regions which lead the fashion in modern days. Scandinavian knitting techniques have been diffused into the east coast of England and Northern Europe by Vikings. 2. Scandinavian countries are distinguished from other countries by their conservative but creative cultural tradition. Their knitting patterns are characterized by small geometric figures such as dots, triangles, squares, rhombuses, and crosses used often with stars and roses. Scandinavian knitting is also salient for its vertical stripes and simple motifs repeating at short intervals. 1) Norway ; Simple and geometric Norwegian patterns are classified into three groups of motifs: (a) the motifs of cross, diamond, X, and swastika (equation omitted). (b) the motifs of human figures, animals and birds, (c) floral motifs (especially eight-petal roses). Their use of color is also simple, and is limited to more than two colors. (2) Sweden ; Swedish patterns are colorful and geometric. They are characterized by features such as brocade, complex embroidery, and contrast of red and black colors. They also show Guernsey patterns. Initials and production years were knitted in sweaters which have different patterns in their trunks and sleeves. 3) Denmark ; The Danish pattern is the purl stitch knitted against the stockinette stitch. The technique is used to copy woven damask motifs. The patterns are seen most clearly when they are knit with smooth yarn. The Faeroe sweaters are the representative work of Danish knitting. Faeroe knitting, incorporates stranded pattern and is knit in the round, either with circular needles. 4) Finland ; Finnish patterns are similar to Norwegian patterns. Finnish knitted work show very colorful, variety and free-flowing geometric patterns. 5) Iceland ; Icelandic knitting shows original ribbon pattern. Lope sweater is the representative work. 3. The traditional knitting patterns not only carried symbolic meanings but also served as means of communication. First of all, patterns had incantatory meanings. Patterns were symbolic of one's social standing, too. The colors, motifs and their arrangements were very important features symbolizing one's social position or family line. People often communicated by certain pieces of knitted work or patterns. In short, the knitted work in the Nordic sweaters served the function of admiring the beauty of nature and symbolizing various meanings. The unique designs and colors of the knitted work reflected the characteristics of the culture those works belonged to. This study also turns our attention to the issue of how the traditional colors and designs of the knitted work can contribute to the development of modern designs, and by doing so, if makes us realize the importance of knitted works in modern society.

• 생명과학회지
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• 제14권1호
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• pp.21-25
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• 2004

Crystal violet와 malachite green색소 분해에 관여하는 유전자들을 규명하기 위하여 색소분해능을 가진 Citrobacter sp.의 염색체 DNA속에의 transposon 도입에 의해 생성된 무작위 변이주들이 분리되었다. 이들 변이 주들로부터 두가지 색소분해능을 소실한 14개의 변이주들이 선별되었고, 이들로부터 염색체 DNA를 분리하여 EcoRl으로 절단한 후 Tn5 단편을 probe로하여 Southern hybridization을 행한 결과, 염색체 DNA상의 각각 다른 부위에 Transposon이 Single 삽입된 5개의 변이주 (Cmg2, Cmg6, Cmg8, Cmgll, Cmg12)가 최종적으로 분리되었다. 이들 변이주들의 Transposon 삽입부위 주위의 염기서열과 이로부터 유추되는 아미노산서열을 database상에 등록되어 있는 유전자의 염기서열과 단백질의 아미노산 서열에 대한 상동성을 비교한 결과, Cmg2는 대장균 maltose trnasporter (Mal C)이고, Cmg6은 LysR-type 전사조절 단백질이며, Cmg12는 산화환원효소를 코드하는 유전자인 것으로 알려졌고, 나머지 Cmg8과 Cmg11은 아직까지 기능이 알려져 있지 않은 단백질을 코드하는 유전자인 것으로임이 판명되었다.

• 대한수학교육학회지:수학교육학연구
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• 제8권2호
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• pp.587-603
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• 1998

Being in Learning-accomplishing rate on mutual cooperation studies of small group by different class, we can find that the sujective class of high group is much more efficient than the compared class of high group and that the subjective class of low group is more efficient than the compared class of low group as times goes. Moreover, in analysis of all directions on mathematical attitude, high group appears to be a great efficient in all areas such as confidence, flexibility, reaction, value, etc. and low group seems to have a little effect, by comparing the subjective class with the compared class. A. The result of a scholastic ability test High group had a great effect in the result of the first (Number and an expression) and second(An equation of a figure) scholastic ability test. As the time of research goes, the difference of average between the subjective class and the compared class has increased. Low group had no effect in the result of the first (Number and an expression) and the second (An equation of figure) scholastic ability test. But the difference of average grade between the subjective class and the compared class proved to be some efficient as time goes. (the first test is 0.94 and the second test is 3.33)We can find that the result of the third test (An exponent and log function) turned out be efficient. B. The change of mathematical attitudeHigh group had a great effect in confidence(+1.21), fiexibility(+1.92), will(-0.06), curiosity(+2.64), reaction(+1.50), value(+1.44). Low group appeared to be a little efficient in comparison between the subjective class and compared class. the average of both the subjective class and the compared class in low group decreased if not the result of pre-test but in that of pose-test. Therefore, we can find that the difference between mathematics of maddle school and that of high school gets bigger in Low group.C. The result of a question examinationAfter this research, the reaction that It is helpful to studying accomplishm- ent is 33.7%, the reaction that It is not helpful is 14.7%. After all, this research appears to be a positive reaction. After this study, the change of studying will seems to be much more not in Low group but in High group.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.97-105
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• 2007

수문학적 토양유형은 복잡하게 세분되어 있는 토양의 종류를 수문학적인 목적에 따라 단순화하기 위해 만든 것으로 미농무성 토양보전국에서 고안한 개념이다. 우리나라 토양을 이 방법으로 구분하고자 하는 몇번의 시도가 있으며 그 중 대표적인 것이 정 등(1995)이 분류한 수문학적 토양군이다. 이는 토양의 침투 투수특성에 대한 실측자료가 부족한 우리나라의 실정을 감안하여 토성속(textural family), 배수등급(drainage class), 불투수층(impermeable layer), 투수성(permeability)의 네가지 토양특성을 분류특성으로 하여 각각에 1-4점 범위로 점수를 매긴 후 합산한 점수를 기준으로 수문학적 토양유형을 분류하는 것이다. 최근에는 토양의 한계침투속도에 따라 수문학적 토양유형을 분류하고자 하는 시도가 있으며 본 논문에서는 새로운 방법으로 분류할 때 기존의 방법과 어떠한 차이가 있는지 비교하고자 하였다. 정 등(1995)의 분류방법은 개념상 몇가지 문제점을 안고 있다. 먼저 토양의 수리특성은 같은 토성속이라 하여도 토양생성 과정과 토지이용 방법에 따라 그 차이가 매우 큼에도 불구하고 이에 대해 고려하지 못하였으며 다음으로 지표유거가 많아 배수가 양호한 토양의 강우 유출을 과소평가한다. 또한 얕은 토심에 존재하는 불투수층이 존재하는 경우 토양의 수리특성에 관계없이 적은 양의 강우에도 유출이 발생하므로 별도의 제한인자로 간주하여야 한다. 토양의 한계 침투속도를 이용한 분류방법은 이러한 문제점을 상당 부분 개선할 수 있다. 토양의 한계침투속도를 산정하기 위해 현장에서 지표 한계침투속도와 투수속도를 측정하였으며 이 자료를 확장하여 해석하기 위해 입자특성을 이용한 Pedo Transfer Function을 개발하였다. 토심 50 cm 포화시 토양 투수성을 한계 침투속도로 가정하였으며 50 cm 이내에 암반층과 지하수위가 존재할 경우 투수성에 관계없이 D유형으로 분류하였다. 새로운 방법으로 분류한 결과 기존의 분류와 몇가지 차이점이 발견되었다. 가장 큰 차이는 대부분의 논토양이 느린 한계침투속도의 영향으로 D유형에 속한 것이다. 산림토양과 밭토양은 기존 방법과 마찬가지로 A, B유형이 많았으며 암반층을 고려하기 전에는 기존 분류에 비해 강우 유출 가능성이 적은 쪽으로 평가되었다. 그러나 암반층이 존재하는 토양을 고려한 결과 A 또는 B 유형에 속하던 상당수의 산림토양이 새로운 분류에서 D유형으로 분류되었다. 지표 유거가 많아 배수등급이 매우양호로 분류되던 토양은 정 등(1995)의 분류와 비교하여 대부분 강우 유출 가능성이 큰 쪽으로 조정되었다. 새로운 수문학적 토양유형을 이용할 경우 낮은 토심에서 암반층이 발견되는 산림토양이 분포한 유역이나 산림, 밭 등에 식질 토양이 많이 분포하는 유역에서는 기존의 방법을 이용하는 것보다 강우 유출량이 높게 평가될 것으로 판단된다. 앞으로 강우 유출량 실측자료와의 비교를 통해 지속적인 보정을 하여야 할 것이며 특히 불투수층의 존재시 일괄적으로 D유형으로 분류된 토양의 경우 깊이에 따라 C 또는 D 유형으로 세분하여 조정할 필요가 있다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.62-72
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• 2002

This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

• 대한치과보철학회지
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• 제45권6호
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• pp.735-742
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• 2007

Statement of problem. Although a number of previous investigations have been carried out on the polymerization shrinkage-strain kinetics of provisional crown and fixed partial denture (FPD) materials, the effect of the changes of liquid monomer to powder ratio on its polymerization shrinkage-strain kinetics has not been reported. Purpose. The purpose of this study was to investigate the influence of liquid monomer to powder ratio of polymer-based provisional crown and FPD materials on the polymerization shrinkage-strain kinetics. Material and methods. Chemically activated acrylic provisional materials (Alike, Jet, Snap) were investigated. Each material was mixed with different liquid monomer to powder ratios by volume (1.0:3.0, 1.0:2.5, 1.0:2.0, 1.0:1.5, 1.0:1.0). Time dependent polymerization shrinkage- strain kinetics of all materials was measured by the bonded-disk method as a function of time at $23^{\circ}C$. Five recordings were taken for each ratio. The results were statistically analyzed using one-way ANOVA and the multiple comparison Scheffe test at the significance level of 0.05. Trends were also examined by linear regression. Results. At 5 minutes after mixing, the polymerization shrinkage-strains of all materials ranged from only 0.01% to 0.49%. At 10 minutes, the shrinkage-strain of Alike was the highest, 3.45% (liquid monomer to powder ratio=1.0:3.0). Jet and Snap were 2.69% (1.0:2.0) and 1.58% (1.0:3.0), respectively (P>0.05). Most shrinkage (94.3%-96.5%) occurred at 30 minutes after mixing for liquid monomer to powder ratio, ranging from 1.0:3.0 to 1.0:1.0. The highest polymerization shrinkage-strain values were observed for the liquid monomer to powder ratio of 1.0:3.0. At 120 minutes after mixing, the shrinkage-strain values were 4.67%, 4.18%, and 3.07% for Jet, Alike, and Snap, respectively. As the liquid monomer to powder ratio increased, the shrinkage-strain values tend to be decreased linearly (r=-0.769 for Alike, -0.717 for Jet, -0.435 for Snap, $r^2=0.592$ for Alike, 0.515 for Jet, 0.189 for Snap; P<0.05). Conclusion. The increase of the liquid monomer to powder ratio from 1.0:3.0 to 1.0:1.0 had a significant effect on the shrinkage-strain kinetics of polymer-based crown and FPD materials investigated. This increased the working time and decreased the shrinkage-strain during polymerization.

• KIEE International Transaction on Systems and Control
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• 제2D권2호
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• pp.78-91
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• 2002

In the thermal power plant, there are six manipulated variables: main steam flow, feedwater flow, fuel flow, air flow, spray flow, and gas recirculation flow. There are five controlled variables: generator output, main steam pressure, main steam temperature, exhaust gas density, and reheater steam temperature. Therefore, the thermal power plant control system is a multinput and output system. In the control system, the main steam temperature is typically regulated by the fuel flow rate and the spray flow rate, and the reheater steam temperature is regulated by the gas recirculation flow rate. However, strict control of the steam temperature must be maintained to avoid thermal stress. Maintaining the steam temperature can be difficult due to heating value variation to the fuel source, time delay changes in the main steam temperature versus changes in fuel flow rate, difficulty of control of the main steam temperature control and the reheater steam temperature control system owing to the dynamic response characteristics of changes in steam temperature and the reheater steam temperature, and the fluctuation of inner fluid water and steam flow rates during the load-following operation. Up to the present time, the Proportional-Integral-Derivative Controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper focuses on the characteristic comparison of the PID controller and the modified 2-DOF PID Controller (Two-Degrees-Freedom Proportional-Integral-Derivative) on the DCS (Distributed Control System). The method is to design an optimal controller that can be operated on the thermal generating plant in Seoul, Korea. The modified 2-DOF PID controller is designed to enable parameters to fit into the thermal plant during disturbances. To attain an optimal control method, transfer function and operating data from start-up, running, and stop procedures of the thermal plant have been acquired. Through this research, the stable range of a 2-DOF parameter for only this system could be found for the start-up procedure and this parameter could be used for the tuning problem. Also, this paper addressed whether an intelligent tuning method based on immune network algorithms can be used effectively in tuning these controllers.

• Journal of Gastric Cancer
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• 제22권2호
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• pp.135-144
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• 2022

Purpose: This study aimed to compare the surgical and oncological outcomes between totally laparoscopic pylorus-preserving gastrectomy (TLPPG) with intracorporeal anastomosis and laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) with extracorporeal anastomosis. Materials and Methods: A retrospective analysis was performed in 258 patients with cT1N0 gastric cancer who underwent laparoscopic pylorus-preserving gastrectomy using two different anastomosis methods: TLPPG with intracorporeal anastomosis (n=88) and LAPPG with extracorporeal anastomosis (n=170). The following variables were compared between the two groups to assess the postoperative surgical and oncological outcomes: proximal and distal margins, number of resected lymph nodes (LNs) in total and in LN station 6, operation time, postoperative hospital stay, and postoperative morbidity including delayed gastric emptying (DGE). Results: The average length of the proximal margin was similar between the TLPPG and LAPPG groups (2.35 vs. 2.73 cm, P=0.070). Although the distal margin was significantly shorter in the TLPPG group than in the LAPPG group (3.15 vs. 4.08 cm, P=0.001), no proximal or distal resection margin-positive cases were reported in either group. The average number of resected LN was similar in both groups (36.0 vs. 33.98, P=0.229; LN station 6, 5.72 vs. 5.33, P=0.399). The operation time was shorter in the TLPPG group than in the LAPPG (200.17 vs. 220.80 minutes, P=0.001). No significant differences were observed between the two groups in terms of postoperative hospital stay (9.38 vs. 10.10 days, P=0.426) and surgical complication rate (19.3% vs. 22.9%), including DGE (8.0% vs. 11.8%, P=0.343). Conclusions: The oncological safety and postoperative complications of TLPPG with intracorporeal anastomosis are similar to those of LAPPG with extracorporeal anastomosis.