• Journal of Global Scholars of Marketing Science
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• v.20 no.2
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• pp.219-230
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• 2010

Digital content makes big changes to our daily lives while bringing opportunities and challenges for companies. Creative firms integrate pictures, texts, videos, audios, and data by digitalization to develop new products or services and create digital experiences to promote their brands. Most articles on digital content contribute to the basic concept or development of marketing it in literature. Actually, compared with traditional value chains for common products or services, the digital content industry seems to have more potential value. Because quite a bit of digital content is free to the consumer, price is not necessarily perceived as an indicator of the quality or value of information (Rowley 2008). It becomes evident that a current theme in digital content is the issue of "value," and research on customers' perceived value of digital content is a necessity. This article argues that experiential value has an advantage in customers' evaluations of digital content. Two different but related contributions to the understanding of "value" of digital content are made here. First, based on the comparison of digital content with products and services, the article proposes two key characteristics that make experiential strategy available for digital content: intangibility and near-zero reproduction cost. On top of that, based on the discussion of the gap between company's idealized value and customer's perceived value, this article emphasizes that digital content prices and pricing of digital content is different from products and services. As a result of intangibility, prices may not reflect customer value. Moreover, the cost of digital content in the development stage may be very high while reproduction costs shrink dramatically. Moreover, because of the value gap mentioned before, the pricing polices vary for different digital contents. For example, flat price policy is generally used for movies and music (Magiera 2001; Netherby 2002), while for continuous demand, digital content such as online games and anti-virus programs involves a more complicated matter of utility and competitive price levels. Digital content companies have to explore various kinds of strategies to overcome this gap. Rethinking marketing solutions such as advertisements, images, and word-of-mouth and their effect on customers' perceived value becomes essential. China's digital content industry is becoming more and more globalized and drawing special attention from different countries and regions that have respective competitive advantages. The 2008-2009 Annual Report on the Development of China's Digital Content Industry (CCIDConsulting 2009) indicates that, with the driven power of domestic demand and governmental policy support, the country's digital content industry maintained a fast growth of some 30 percent in 2008, obviously indicating the initial stage of industry expansion. In China, anti-virus programs and other software programs which need to be updated use a quarter-based pricing policy. Customers can download a trial version for free and use it for six months or a year. If they want to use it longer, continuous payment is needed. They examine the excellence of the digital content during this trial period and decide whether to pay for continued usage. For China’s music and movie industries, as a result of initial development, experiential strategy has not been much applied, even though firms in other countries find the trial experience and explore important strategies(such as customers listening to music for several seconds for free before downloading it). For the above reasons, anti-virus program may be a representative for digital content industry in China and an exploratory study of the advantage of experiential value in customer's perceived value of digital content is done in the anti-virus market of China. In order to enhance the reliability of the survey data, this study focused on people who were experienced users of anti-virus programs. The empirical results revealed that experiential value has a positive effect on customers' perceived value of digital content. In other words, because digital content is intangible and the reproduction costs are nearly zero, customers' evaluations are based heavily on their experience. Moreover, image and word-of-mouth do not have a positive effect on perceived value, only on experiential value. That is to say, a digital content value chain is different from that of a general product or service. Experiential value has a notable advantage and mediates the effect of image and word-of-mouth on perceived value. The results of this study help provide an understanding of why free digital content downloads exist in developing countries. Customers can perceive the value of digital content only by using and experiencing it. This is also why such governments support the development of digital content. Other developing countries whose digital content business is also in the beginning stage can make use of the suggestions here. Moreover, based on the advantage of experiential strategy, companies should make more of an effort to invest in customers' experience. As a result of the characteristics and value gap of digital content, customers perceive more value in the intangible digital content only by experiencing what they really want. Moreover, because of the near-zero reproduction costs, companies can perhaps use experiential strategy to enhance customer understanding of digital content.

• Pediatric Infection and Vaccine
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• v.6 no.1
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• pp.78-85
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• 1999

Purpose : Mycoplasma pneumoniae pneumonia has been to be developed frequently in school age children and adolescence and hard to see under 3 year-old children. But it seems to be increased in number of patients with Mycoplasma pneumoniae pneumonia under 3-year old in clinical practice in these days. We have aimed to examine the characteristics of clinical findings of Mycoplasma pneumonia under 3 year-old children. Methods : We had performed retrospective review of medical records of 30 patients with Mycoplasmal pneumonia under 3-year old children who admitted to Department of Pediatrics, Kyunghee University Hospital from Jan. 1994 to Dec. 1997. The diagnostic criteriae was Cold agglutinin titer>1:64 or Mycoplasma antibody titer>1:80. Results : Mycoplasmal pneumonia was 30 out of 235 cases(12.7%) of total pneumonia under 3 year old children. Male female ratio was 1.3 : 1 and age distributions were 0~1y : 0, 1~2y : 8, 2~3y : 22 cases. Clinical symptoms and signs were cough(100.0%), sputum(83.3%), fever(80.0%) rhinorrhea(33.3%), vomiting(33.3%), moist rale(86.7%), decreased breathing sound(26.7%), wheezing(20.0%), and pharyngeal injection(30.0%). Thirteen out of 30 cases(43.3%) had unilateral infiltration, 10 cases(33.4%) had bilateral infiltration, 1 case(3.3%) had pleural effusion, and 6 cases(20.0%) had negative findings on chest radiography and there was no cases of atelectasis. On laboratory findings, 6 out of 30 cases(20.0%) had leukocytosis, 1 case(3.3%) had neutrophilia, 10 cases(30.0%) had eosinophilia, 17 cases(56.7%) had increased ESR, and 18 cases(60.6%) had positive CRP. Positive cold agglutinin titers(>1 : 64) were 19 cases(63.3%), and positive mycoplasma antibody(M-ab) titers(>1 : 80) were 27 cases(93.3%). Mycoplasma antibody test was more valuable than cold agglutinin test for the diagnosis of Mycoplasmal pneumonia and there was no correlation between cold agglutinin titer and mycoplasma antibody titer. Mycoplasma-polymerase chain reaction(M-PCR) was done with 13 cases, 12 out of 13 cases(92.3%) were positive. M-PCR test was valuable to the diagnosis of Mycoplasmal pneumonia but it will be needed to further study for their clinical application. Among 30 cases, 5 cases(16.7%) had complications, 3 cases(10.0%) had skin rash, 1 case(3.3%) had pleural effusion, 1 case(3.3%) had arthralgia, but all complications were mild and recovered without residual sequelae. Conclusion : The occurrence of Mycoplasmal pneumonia under 3 year-old children was not rare from this study. Clinical characteristics of Mycoplasmal pneumonia under 3-year old were normal radiologic findings in many cases, low complication rate, mild clinical course, and tend to rapid recovery compared with general manifestations of Mycoplasmal infectionsin children and adolescence. There were likely to be missed patients with Mycoplasmal pneumonia which did not diagnose by conventional serologic tests that had low sensitivity and specificity. We have to pay attention to the Mycoplasmal infection of the young children with pneumonia during epidemic periods of Mycoplasmal infection.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.161-174
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• 1997

Omega-3 fatty acids have been major research interests in medical and nutritional science relating to life sciences since after the epidemiologic data on Green3and Eskimos reported by several researchers clearly showed fewer per capita deaths from heart diseases and a lower incidence of adult diseases. Linolenic acid(LNA) is an essential fatty acid for human beings as well as linoleic acid(LA) due to the fact that vertebrates lack an enzyme required to incorporate a double bond beyond carbon 9 in the chain. In addition the ratio of omega-6 and 3 fatty acids seems to be important in terms of alleviation of heart diseases since LA and LNA competes for the metabolic pathways of eicosanoids synthesis. High consumption of omega-3 fatty acids in seafoods may control heart diseases by reducing blood cholesterol, triglyceride, VLDL, LDL and increasing HDL and by inhibiting plaque development through the formation of antiaggregatory substances like PGI$_2$, PGI$_3$ and TXA$_3$ metabolized from LNA. Omega 3 fatty acids also play an important role in neuronal developments and visual functioning, in turn influence learning behaviors. Current dietary sources of omega-3 fatty acids are limited mostly to seafoods, leafy vegetables, marine and some seed oils and the most appropriate way to provide omega-3 fatty acids is as a part of the normal dietary regimen. The efforts to enhance the intake of omega-3 fatty acids due to several beneficial effects have been made nowadays by way of food processing technology. Two different ways can be applied: one is add Purified and concentrated omega-3 fatty acids into foods and the other is to produce foods with high amounts of omega-3 fatty acids by raising animals with specially formulated feed best for the transfer of omega-3 fatty acids. Recently, items of manufactured and marketed omega-3 fatty acids fortified foodstuffs are pork, milk, cheese, egg, formula milk and ham. In domestic food market, many of them are distributed already, but problem is that nutritional informations on the amounts of omega-3 fatty acids are not presented on the labeling, which might cause distrust of consumers on those products, result in lower sales volumes. It would be very much wise if we consume natural products, result in lower sales volumes. It would be very much wise if we consume natural products high in omega-3 fatty acids to Promote health related to many types of adult diseases rather than processed foods fortified with omega-3 fatty acids.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.1-8
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• 2012

This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the porcine MC4R gene and validate the effect of the MC4R genotype for marker assisted selection (MAS). Six amplicons were produced to analyze the entire base sequences of the porcine MC4R gene and six SNPs were detected (c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, c.892A>G-Asp298Asn, and c.*430A>T). Linkage disequilibrium (LD) of the six SNPs was analyzed by performing haploid analysis. There was a perfect linkage disequilibrium in c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, and c.*430A>T. Only the c.892A>G (Asp298Asn) SNP showed a very low LD with an $r^2$ value of 0.028 and the D' value of 0.348. As a result, the two SNPs-c.707A>G (Arg236His) and c.892A>G (Asp298Asn)-were selected to extract the genotype frequencies from the 5 pig breeds by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotype analysis method. The SNP frequency of c.707A>G (Arg236His) indicated the presence of the A (His) allele only in Yorkshire, while the G allele was fixed in the KNP, Landrace, Berkshire, and Duroc. Association analysis was carried out in 484 pigs with the c.707A>G (Arg236His) SNP and the meat quality traits of four different pig cross populations: a significant association was noted in crude fat, sirloin moisture, meat color, and the degree of red and yellow coloration. The frequency of the c.892A>G(Asp298Asn) SNP genotype varied among the breeds; while Duroc showed the highest frequency of the A (Asn) allele, KNP showed the highest frequency of the G (Asp) allele. Association analysis was carried out in 1126 pigs with the c.892A>G (Asp298Asn) SNP and the meat quality traits of four pig populations: a highly significant linkage was noted in the back-fat thickness (P<0.002). It was found that the back-fat thickness was higher in individuals with the AA genotype than in those with the AG or GG genotype. Thus, in this study, we verified that the c.892A>G (Asp298Asn) SNP in the pig MC4R gene has a sufficient effect as a gene marker for MAS in Korean pork industry.

• Journal of the Korean Society of Food Culture
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• v.1 no.2
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• pp.116-126
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• 1986

This study was designed to be a link in the chain of the investigation on daily life and consciousness of longevous people in Korea, and to investigate the regional feature of longevity areas. The daily life and consciousness were investigated on 379 subjects(male 121, female 258) of the aged who were above 80 years of age, from June to November in 1985. This paper is to report the results investigated the longevity rate, distribution, classification and weather of longevity districts, and also the actual conditions such as the functions of daily life and educational degree of longevous people. 1. The number of longevous people in Korea was 171,449 (male 42,842, female 128,607), and the average longevity rate was 0.46% against total population in Korea(male 0.23%, female 0.69%). 2. Of the longevity rates of shi and/or do in Korea, Cheju(1.03%) was the highest among these districts, and decreased in the order of Chonnam(0.79%), Chonbuk(0.66%), Kyongbuk(0.65%) and Kyongnam(0.61%), whereas the large cities such as Inchon(0.22%), Seoul(0.23%), Pusan(0.23%) and Taegu(0.28%) were remarkably lower than districts in seasides and mountains. 3. The districts above 1.0% of longevity rate in Korea showed 17-guns, and the distribution of these districts was 10-guns of Chonnam, 2-guns of Kyongbuk and Kyongnam, and 1-gun of Kyonggi, Cho-nbuk and Cheju, respectively. 4. Of these districts, Pukcheju(1.65%) was the highest, and decreased in the order of Namhae(1.56%), Sungju(1.24%), Posong(1.22%) and Koksong(1.20%). The highest figure(male 0.71%, female 2.51%) was observed in Pukcheju as contrasted with 0.23%(male) and 0.69%(female) of the average longevity rate in Korea. 5. The sex ratio of longevous people in Korea showed the female/male ratio of 3.0. It is, therefore, believed that the longevity rate of female was 3 times higher than that of male. 6. The longevity districts were classified into seven districts in seasides, three districts in isolated islands, and seven rural districts in mountains. 7. The situation of weather in longevity districts was in the range of 11.2 to $14.8^{\circ}C$ at annual average temperature, and 878.5 to 1585.9mm at annual average rainfall. 8. Of the educational degree of longevous people, uneducated(71.5%) was the highest, and followed by the order of village school(15.8%) and above elementary school(4.8%). 9. In the functions of daily life, the aged moving actively(53.0%) was the highest among these longevous people, followed by the aged moving a little(23.5%). Therefore, it is believed that health degree of these longevous peoples by the functions of daily life was very gratifying.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.216-224
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• 1998

This study was performed to offer the basic and applicable data for improvement of Korean cattle and dairy cattle, according to finding the genetic construction obtained from analysis of genetic polymorphisms of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci related Korean cattle and Holstein cows using PCR-RFLP. Genomic DNA used in this study was prepared from the blood of 253 individuals of Korean cattle in Korean Native Cattle Improvement Center, NLCF, and the blood of 113 individuals of Holstein cows in National Livestock Research Institute. The results obtained are summarized as follows : 1. This study confirmed amplified products of 530bp and 262bp fragments obtained from the amplification of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci in Korean cattle and Holstein breed by PCR. 2. The ${\beta}$-lactoglobulin AA genotype showed 153bp and 109bp fragments, and ${\beta}$-lactoglobulin AB genotype showed 153bp, 109bp, 79bp and 74bp fragments, and BB genotype showed 109bp, 79bp and 74bp fragments in amplified products of ${\beta}$-lactoglobulin loci with the restricted enzyme digestion of Hae III. 3. The ${\kappa}$-casein AA genotype showed a 530bp fragment, and ${\kappa}$-casein AB genotype showed 530bp, 344bp and 186bp fragments, and BB genotype showed 344bp and 186bp fragments in amplified products of ${\kappa}$-casein loci with the restricted enzyme digestion of Taq I. 4. On ${\beta}$-lactoglobulin genotypes and gene frequencies, Korean cattle were 6.72%, 26.09% and 67.19% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.197 and 0.803, and Holstein were 35.40%, 56.64% and 7.96% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.637 and 0.363, respectively. 5. On ${\kappa}$-casein genotypes and gene frequencies, Korean cattle were 46.25%, 39.13% and 14.62% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.658 and 0.342, and Holstein were 60.18% and 38.94% and 0.88% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.796 and 0.204, respectively. 6. As a consequence, the gene frequency was 0.197 and 0.803 for ${\beta}$-lactoglobulin A and B alleles, and 0.658 and 0.342 for ${\kappa}$-casein A and B alleles in Korea cattle, but was 0.637 and 0.363 for ${\beta}$-lactoglobulin A and B alleles, and 0.796 and 0.204 for ${\kappa}$-casein A and B alleles in Holstein, respectively.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.23-40
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• 2011

Objectives: This study was designed to examine the effects of extracts of Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) on the lipid lowering, anti-oxidation and concentration of proinflammatory cytokines and was investigated on hyperlipidemic rats. Methods: Male rats weighing $182.39{\pm}4.71g$ were fed high fat diet for 8 weeks and 36 rats(above 400 g) were divided into 4 groups. Each of 9 rats was divided a control group and experimental groups. We fed a control group of rats a basal diet and administered normal saline(100 mg/kg, 1 time/1 day) for 4 weeks. And we fed each experimental group of rats basal diet and administered an extract of Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) extracts(100 mg/kg, 200mg/kg, 300 mg/kg, 300 mg/kg, 1 time/1 day) for 4 weeks. At the end of the experiment, the rats were sacrificed to determine their chemical composition. We measured lipid of plasma and liver, concentration of proinflmmatory cytokines, anti-oxidative activity and $TNF-{\alpha}$, Apo-B, Apo-E and leptin gene expression. Results: 1. Concentration of plasma free fatty(FFA) showed no significant difference in all the treatment groups. Concentration of plasma triglyceride(TG) showed a significant decrement in the 300 mg/kg in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups than that of control group. 2. Concentration of plasma total cholesterol showed a significant decrement in the 200 and 300 mg/kg in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups than that of control group. Concentration of plasma low density lipoprotein(LDL)-cholesterol showed a Significant decrement in the 300 mg/kg in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups than that of control group. Concentration of plasma high density lipoprotein(HDL)-cholesterol showed a significant increment in the 300 mg/kg in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) group. 3. Concentration of liver total cholesterol showed a tendence to decrease in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups. Concentration of liver TG showed a significant decrement in all Ojeoksangamibang groups than that of control group. 4. Concentration of plasma and liver thiobarbituric acid reactive substance(TBARS) showed a tendence to decrease in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups. 5. The values of glutathione peroxidase(GSH-Px), superoxide dismutase(SOD) and catalase(CAT) activity showed a significant increment in all Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups than that of control group. 6. The values of plasma aspartate aminotransferase(AST) and alanine aminotransferase(ALT) activity showed no significant different in all treatment group. 7. Concentration of plasma $interleukin(IL)-1{beta}$ showed no significant difference in all the treatment groups. Concentration of plasma IL-6 showed a significant decrement in the 300 mg/kg in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) group than that of control group. Concentration of plasma tumor necrosis $factor-{\alpha}(TNF-{\alpha})$ a siginifant decrement in the 200 and 300 mg/kg in Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) group than that of control group. However the concentration of plasma IL-10 in the 300 mg/kg Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups showed a significant increment than that of control group. 9. In the analysis of reverse transcription-polymerase chain reaction(RT-PCR), gene expression of $TNF-{\alpha}$, Apo-B and Apo-E in the Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups showed a lower expression than that of control group. However the gene expression of leptin showed no difference in the treatment groups. 10. The ratio of $TNF-{\alpha}$, Apo-B, and Apo-E per ${\beta}-actin$ expression in the Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) groups showed a significant decrement than that of control group. However The ratio of leptin expression per ${\beta}-actin$ expression showed no significant difference among all the treatment groups. Conclusions: According to above results, in lowering lipid effect, anti-oxidation and control of pro-inflammatory cytokines production, Ojeoksangamibang($W{\check{u}}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) gives effect.

• Tuberculosis and Respiratory Diseases
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• v.58 no.6
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• pp.590-599
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• 2005

Object : Cigarette smoking is a major cause of mucus hypersecretion, which is a pathophysiological feature of many inflammatory airway diseases. Mucins, which are an important part of the airway mucus, are synthesized from the Muc gene in airway epithelial cells. However, the signaling pathways for cigarette smoke-induced mucin synthesis are unknown. The aim of this study was to determine the signal pathway for smoking induced Muc5ac gene expression. Methods : A549 cells were cultured and transiently transfected with the Muc5ac promoter fragment. These cells were stimulated with 5% cigarette smoke extract (CSE) alone or with CSE after a pretreatment with various signal transduction pathway inhibitors (AG1478, PD98059 and SB203580). The Muc5ac promoter activity was examined using the luciferase reporter system, and the level of phosphorylated EGFR, ERK1/2, p38 MAPK and JNK were all examined using Western blot analysis. Muc5ac mRNA expression was also examined using reverse transcriptase polymerase chain reactions (RT-PCR). Results : 1. The peak level of luciferase activity of the Muc5ac promoter was observed at 5% concentration and after 3 hours of incubation with the CSE. The level of EGFR phosphorylation and the luciferase activity of the transfected cells caused by the CSE were significantly suppressed by AG1478 or PD98059 (P<0.01). 2. CSE phosphorylated ERK1/2 or p38 MAPK but not JNK. The Muc5ac mRNA expression level was increased by the CSE but that was suppressed by PD98059 or AG1478. 3. The CSE-induced phosphorylation of ERK1/2 was blocked by PD98059 and that of p38 MAPK was blocked by either PD98059 or SB203580. Either PD98059 or SB203580 suppressed the luciferase activity of the transfected cells (P<0.0001). Conclusion : The Muc5ac mRNA expression level was increased by the CSE. The increased CSE-induced transcriptional activity was mediated via EGF receptor activation, which led to ERK1/2 and p38 MAPK phosphorylation.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.19-20
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• 2016

Sesquiterpenoids are defined as $C_{15}$ compounds derived from farnesyl pyrophosphate (FPP), and their complex structures are found in the tissue of many diverse plants (Degenhardt et al. 2009). FPP's long chain length and additional double bond enables its conversion to a huge range of mono-, di-, and tri-cyclic structures. A number of cyclic sesquiterpenes with alcohol, aldehyde, and ketone derivatives have key biological and medicinal properties (Fraga 1999). Fungi, such as the wood-rotting Polyporus brumalis, are excellent sources of pharmaceutically interesting natural products such as sesquiterpenoids. In this study, we investigated the biosynthesis of P. brumalis sesquiterpenoids on modified medium. Fungal suspensions of 11 white rot species were inoculated in modified medium containing $C_6H_{12}O_6$, $C_4H_{12}N_2O_6$, $KH_2PO_4$, $MgSO_4$, and $CaCl_2$ for 20 days. Cultivation was stopped by solvent extraction via separation of the mycelium. The metabolites were identified as follows: propionic acid (1), mevalonic acid lactone (2), ${\beta}$-eudesmane (3), and ${\beta}$-eudesmol (4), respectively (Figure 1). The main peaks of ${\beta}$-eudesmane and ${\beta}$-eudesmol, which were indicative of sesquiterpene structures, were consistently detected for 5, 7, 12, and 15 days These results demonstrated the existence of terpene metabolism in the mycelium of P. brumalis. Polyporus spp. are known to generate flavor components such as methyl 2,4-dihydroxy-3,6-dimethyl benzoate; 2-hydroxy-4-methoxy-6-methyl benzoic acid; 3-hydroxy-5-methyl phenol; and 3-methoxy-2,5-dimethyl phenol in submerged cultures (Hoffmann and Esser 1978). Drimanes of sesquiterpenes were reported as metabolites from P. arcularius and shown to exhibit antimicrobial activity against Gram-positive bacteria such as Staphylococcus aureus (Fleck et al. 1996). The main metabolites of P. brumalis, ${\beta}$-Eudesmol and ${\beta}$-eudesmane, were categorized as eudesmane-type sesquiterpene structures. The eudesmane skeleton could be biosynthesized from FPP-derived IPP, and approximately 1,000 structures have been identified in plants as essential oils. The biosynthesis of eudesmol from P. brumalis may thus be an important tool for the production of useful natural compounds as presumed from its identified potent bioactivity in plants. Essential oils comprising eudesmane-type sesquiterpenoids have been previously and extensively researched (Wu et al. 2006). ${\beta}$-Eudesmol is a well-known and important eudesmane alcohol with an anticholinergic effect in the vascular endothelium (Tsuneki et al. 2005). Additionally, recent studies demonstrated that ${\beta}$-eudesmol acts as a channel blocker for nicotinic acetylcholine receptors at the neuromuscular junction, and it can inhibit angiogenesis in vitro and in vivo by blocking the mitogen-activated protein kinase (MAPK) signaling pathway (Seo et al. 2011). Variation of nutrients was conducted to determine an optimum condition for the biosynthesis of sesquiterpenes by P. brumalis. Genes encoding terpene synthases, which are crucial to the terpene synthesis pathway, generally respond to environmental factors such as pH, temperature, and available nutrients (Hoffmeister and Keller 2007, Yu and Keller 2005). Calvo et al. described the effect of major nutrients, carbon and nitrogen, on the synthesis of secondary metabolites (Calvo et al. 2002). P. brumalis did not prefer to synthesize sesquiterpenes under all growth conditions. Results of differences in metabolites observed in P. brumalis grown in PDB and modified medium highlighted the potential effect inorganic sources such as $C_4H_{12}N_2O_6$, $KH_2PO_4$, $MgSO_4$, and $CaCl_2$ on sesquiterpene synthesis. ${\beta}$-eudesmol was apparent during cultivation except for when P. brumalis was grown on $MgSO_4$-free medium. These results demonstrated that $MgSO_4$ can specifically control the biosynthesis of ${\beta}$-eudesmol. Magnesium has been reported as a cofactor that binds to sesquiterpene synthase (Agger et al. 2008). Specifically, the $Mg^{2+}$ ions bind to two conserved metal-binding motifs. These metal ions complex to the substrate pyrophosphate, thereby promoting the ionization of the leaving groups of FPP and resulting in the generation of a highly reactive allylic cation. Effect of magnesium source on the sesquiterpene biosynthesis was also identified via analysis of the concentration of total carbohydrates. Our current study offered further insight that fungal sesquiterpene biosynthesis can be controlled by nutrients. To profile the metabolites of P. brumalis, the cultures were extracted based on the growth curve. Despite metabolites produced during mycelia growth, there was difficulty in detecting significant changes in metabolite production, especially those at low concentrations. These compounds may be of interest in understanding their synthetic mechanisms in P. brumalis. The synthesis of terpene compounds began during the growth phase at day 9. Sesquiterpene synthesis occurred after growth was complete. At day 9, drimenol, farnesol, and mevalonic lactone (or mevalonic acid lactone) were identified. Mevalonic acid lactone is the precursor of the mevalonic pathway, and particularly, it is a precursor for a number of biologically important lipids, including cholesterol hormones (Buckley et al. 2002). Farnesol is the precursor of sesquiterpenoids. Drimenol compounds, bi-cyclic-sesquiterpene alcohols, can be synthesized from trans-trans farnesol via cyclization and rearrangement (Polovinka et al. 1994). They have also been identified in the basidiomycota Lentinus lepideus as secondary metabolites. After 12 days in the growth phase, ${\beta}$-elemene caryophyllene, ${\delta}$-cadiene, and eudesmane were detected with ${\beta}$-eudesmol. The data showed the synthesis of sesquiterpene hydrocarbons with bi-cyclic structures. These compounds can be synthesized from FPP by cyclization. Cyclic terpenoids are synthesized through the formation of a carbon skeleton from linear precursors by terpene cyclase, which is followed by chemical modification by oxidation, reduction, methylation, etc. Sesquiterpene cyclase is a key branch-point enzyme that catalyzes the complex intermolecular cyclization of the linear prenyl diphosphate into cyclic hydrocarbons (Toyomasu et al. 2007). After 20 days in stationary phase, the oxygenated structures eudesmol, elemol, and caryophyllene oxide were detected. Thus, after growth, sesquiterpenes were identified. Per these results, we showed that terpene metabolism in wood-rotting fungi occurs in the stationary phase. We also showed that such metabolism can be controlled by magnesium supplementation in the growth medium. In conclusion, we identified P. brumalis as a wood-rotting fungus that can produce sesquiterpenes. To mechanistically understand eudesmane-type sesquiterpene biosynthesis in P. brumalis, further research into the genes regulating the dynamics of such biosynthesis is warranted.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.151-171
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• 2014

Firms today have sought management effectiveness and efficiency utilizing information technologies (IT). Numerous firms are outsourcing specific information systems functions to cope with their short of information resources or IT experts, or to reduce their capital cost. Recently, Software-as-a-Service (SaaS) as a new type of information system has become one of the powerful outsourcing alternatives. SaaS is software deployed as a hosted and accessed over the internet. It is regarded as the idea of on-demand, pay-per-use, and utility computing and is now being applied to support the core competencies of clients in areas ranging from the individual productivity area to the vertical industry and e-commerce area. In this study, therefore, we seek to quantify the value that SaaS has on business performance by examining the relationships among firm strategies, SaaS technology maturity, and business performance of SaaS providers. We begin by drawing from prior literature on SaaS, technology maturity and firm strategy. SaaS technology maturity is classified into three different phases such as application service providing (ASP), Web-native application, and Web-service application. Firm strategies are manipulated by the low-cost strategy and differentiation strategy. Finally, we considered customer acquisition as a business performance. In this sense, specific objectives of this study are as follows. First, we examine the relationships between customer acquisition performance and both low-cost strategy and differentiation strategy of SaaS providers. Secondly, we investigate the mediating and moderating effects of SaaS technology maturity on those relationships. For this purpose, study collects data from the SaaS providers, and their line of applications registered in the database in CNK (Commerce net Korea) in Korea using a questionnaire method by the professional research institution. The unit of analysis in this study is the SBUs (strategic business unit) in the software provider. A total of 199 SBUs is used for analyzing and testing our hypotheses. With regards to the measurement of firm strategy, we take three measurement items for differentiation strategy such as the application uniqueness (referring an application aims to differentiate within just one or a small number of target industry), supply channel diversification (regarding whether SaaS vendor had diversified supply chain) as well as the number of specialized expertise and take two items for low cost strategy like subscription fee and initial set-up fee. We employ a hierarchical regression analysis technique for testing moderation effects of SaaS technology maturity and follow the Baron and Kenny's procedure for determining if firm strategies affect customer acquisition through technology maturity. Empirical results revealed that, firstly, when differentiation strategy is applied to attain business performance like customer acquisition, the effects of the strategy is moderated by the technology maturity level of SaaS providers. In other words, securing higher level of SaaS technology maturity is essential for higher business performance. For instance, given that firms implement application uniqueness or a distribution channel diversification as a differentiation strategy, they can acquire more customers when their level of SaaS technology maturity is higher rather than lower. Secondly, results indicate that pursuing differentiation strategy or low cost strategy effectively works for SaaS providers' obtaining customer, which means that continuously differentiating their service from others or making their service fee (subscription fee or initial set-up fee) lower are helpful for their business success in terms of acquiring their customers. Lastly, results show that the level of SaaS technology maturity mediates the relationships between low cost strategy and customer acquisition. That is, based on our research design, customers usually perceive the real value of the low subscription fee or initial set-up fee only through the SaaS service provide by vender and, in turn, this will affect their decision making whether subscribe or not.