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Mitochondrial DNA Copy Number in the Patients of Korean Polycystic Ovary Syndrome (PCOS) (한국인 다낭성난소증후군 환자에서 미토콘드리아 DNA Copy 수의 정량적 분석)

  • Park, Ji-Eun;Jang, Min-Hee;Cho, Sung-Won;Kim, Yoo-Shin;Won, Hyung-Jae;Cho, Jung-Hyun;Baek, Kwang-Hyun;Lee, Sook-Hwan
    • Clinical and Experimental Reproductive Medicine
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    • v.33 no.4
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    • pp.245-251
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    • 2006
  • Objective: We analyzed quantification of mitochondria DNA (mtDNA) to investigate the relationship of mitochondria and pathogenesis of PCOS. Materials and Methods: Peripheral blood samples were collected from 28 patients with PCOS who were under the inclusion criteria for PCOS and from 28 healthy controls. Genomic DNA was used to analyze real-time PCR for mtDNA copy number quantification. The mtDNA copy number was compared between the control and PCOS groups. All data was expressed as mean ${\pm}$ SD. Statistical analysis was assessed by t-test. Results: In this study, the mtDNA $C_T$ was $11.67{\pm}0.422$ in PCOS patients and $11.51{\pm}0.722$ in control group, respectively. The mtDNA copy number was $1726410.71{\pm}407858.591$ the patients of in PCOS and $2167887.51{\pm}252459.28$ in control group (p=0.08), respectively. Conclusion: In our study, using real-time PCR, there was a tendency of lower mtDNA copy number in the patients of PCOS when comparing to the control group even though statistical difference was not significant. However, more extensive analysis is required to clarity relationship between mtDNA copy number and pathogenesis of PCOS.

Beak Trimming Methods - Review -

  • Glatz, P.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.11
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    • pp.1619-1637
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    • 2000
  • A review was undertaken to obtain information on the range of beak-trimming methods available or under development. Beak-trimming of commercial layer replacement pullets is a common yet critical management tool that can affect the performance for the life of the flock. The most obvious advantage of beak-trimming is a reduction in cannibalism although the extent of the reduction in cannibalism depends on the strain, season, and type of housing, flock health and other factors. Beak-trimming also improves feed conversion by reducing food wastage. A further advantage of beak-trimming is a reduction in the chronic stress associated with dominance interactions in the flock. Beak-trimming of birds at 7-10 days is favoured by Industry but research over last 10 years has shown that beak-trimming at day-old causes the least stress on birds and efforts are needed to encourage Industry to adopt the practice of beak-trimming birds at day-old. Proper beak-trimming can result in greatly improved layer performance but improper beak-trimming can ruin an other wise good flock of hens. Re-trimming is practiced in most flocks, although there are some flocks that only need one trimming. Given the continuing welfare scrutiny of using a hot blade to cut the beak, attempts have been made to develop more welfare friendly methods of beak-trimming. Despite the developments in design of hot blade beak-trimmers the process has remained largely unchanged. That is, a red-hot blade cuts and cauterises the beak. The variables in the process are blade temperature, cauterisation time, operator ability, severity of trimming, age of trimming, strain of bird and beak length. This method of beak-trimming is still overwhelmingly favoured in Industry and there appears to be no other alternative procedures that are more effective. Sharp secateurs have been used trim the upper beak of both layers and turkeys. Bleeding from the upper mandible ceases shortly after the operation, and despite the regrowth of the beak a reduction of cannibalism has been reported. Very few differences have been noted between behaviour and production of the hot blade and cold blade cut chickens. This method has not been used on a large scale in Industry. There are anecdotal reports of cannibalism outbreaks in birds with regrown beaks. A robotic beak-trimming machine was developed in France, which permitted simultaneous, automated beak-trimming and vaccination of day-old chicks of up to 4,500 chickens per hour. Use of the machine was not successful because if the chicks were not loaded correctly they could drop off the line, receive excessive beak-trimming or very light trimming. Robotic beak-trimming was not effective if there was a variation in the weight or size of chickens. Capsaicin can cause degeneration of sensory nerves in mammals and decreases the rate of beak regrowth by its action on the sensory nerves. Capsaicin is a cheap, non-toxic substance that can be readily applied at the time of less severe beak-trimming. It suffers the disadvantage of causing an extreme burning sensation in operators who come in contact with the substance during its application to the bird. Methods of applying the substance to minimise the risk to operators of coming in contact with capsaicin need to be explored. A method was reported which cuts the beaks with a laser beam in day-old chickens. No details were provided on the type of laser used, or the severity of beak-trimming, but by 16 weeks the beaks of laser trimmed birds resembled the untrimmed beaks, but without the bill tip. Feather pecking and cannibalism during the laying period were highest among the laser trimmed hens. Currently laser machines are available that are transportable and research to investigate the effectiveness of beak-trimming using ablasive and coagulative lasers used in human medicine should be explored. Liquid nitrogen was used to declaw emu toes but was not effective. There was regrowth of the claws and the time and cost involved in the procedure limit the potential of using this process to beak-trim birds.

Efficiency and Side Effects of Sorafenib Therapy for Advanced Hepatocellular Carcinoma: A Retrospective Study by the Anatolian Society of Medical Oncology

  • Berk, Veli;Kaplan, Mehmet Ali;Tonyali, Onder;Buyukberber, Suleyman;Balakan, Ozan;Ozkan, Metin;Demirci, Umut;Ozturk, Turkan;Bilici, Ahmet;Tastekin, Didem;Ozdemir, Nuriye;Unal, Olcun Umit;Oflazoglu, Utku;Turkmen, Esma;Erdogan, Bulent;Uyeturk, Ummugul;Oksuzoglu, Berna;Cinkir, Havva Yesil;Yasar, Nurgul;Gumus, Mahmut
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7367-7369
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    • 2013
  • Background: Inoperable and metastatic hepatocellular carcinoma (HCC) is associated with a poor prognosis and low chemotherapeutic efficiency. Sorafenib is an oral multi-kinase inhibitor exerting its effects via the RAF/MEK/ERK pathway, vascular endothelial growth factor receptor (VEGFR) and platelet derived growth factor receptor beta (PDGFR-${\beta}$) tyrosine kinases. Randomized studies have shown a significant contribution of sorafenib to life expectancy and quality of life of cancer patients. The aim of the present study is to evaluate the efficacy and side effects of sorafenib therapy in Turkey. Materials and Methods: Data for 103 patients (82 males, 21 females) receiving sorafenib therapy in 13 centers from February 2008 to December 2012 were evaluated. Median age was 61 years and median ECOG performance status was 1 (range: 0-2). 60 patients (58%) had hepatitis B, 15 patients (15%) had hepatitis C infection and 12 patients (12%) had a history of alcohol consumption. All of the patients had Child scores meeting the utilization permit of the drug in our country (Child A). Results: A total of 571 cycles of sorafenib therapy were administered with a median of four per patient. Among the evaluable cases, there was partial response in 15 (15%), stable disease in 52 (50%), and progressive disease in 36 (35%). Median progression-free survival was 18 weeks and median overall survival was 48 weeks. The dose was reduced only in 6 patients and discontinued in 2 patients due to grade 3-4 toxicity, 18 patients (17%) suffering hand-foot syndrome, 7 (7%) diarrhea, and 2 (2%) vomiting. Conclusions: This retrospective study demonstrated better efficacy of sorafenib therapy in patients with advanced HCC compared to the literature while progression-free survival and overall survival findings were comparable. The side effect rates indicate that the drug was tolerated well. In conclusion, among the available treatment options, sorafenib is an efficient and tolerable agent in patients with inoperable or metastatic HCC.

American Culture at the Crossroad : Debates over NEA(National Endowments for the Arts) (미국 문화, 그 기로에 서서 - NEA(국립예술진흥기금)를 둘러싼 논쟁 중심으로)

  • Kim, Jin-A
    • The Journal of Art Theory & Practice
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    • no.4
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    • pp.33-56
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    • 2006
  • The cultural debates between conservatives and liberals at the end of the 1980s and in the early 1990s were termed as "culture wars." The "culture wars" involved a diverse range of controversial issues, such as the introduction of multicultural curricula in educational institutions, prayers in schools, whether to allow gays to serve openly in the military, and whether abortion should be permitted. The most heated debates of the "culture wars" regarding art raged over the NEA and the question of whether Andres Serrano's works should have been publicly funded, in addition to the exhibition "Robert Mapplethorpe: The Perfect Moment" which were charged as projecting "obscene" or "blasphemous" images. This paper examines the development of culture wars in art and focuses on several issues invoked by the NEA debates. However, it is not a detailed chronological investigation. Rather it pays attention to the several phases of the debates, analyzing and criticizing the clashes of the political and esthetical points of views between conservatives and liberals. How could NEA funding, a mere fraction of the federal budget, have become so critical for both sides(conservative and liberal), for politicians and artists' groups, and for academics and the general public? The art community was astounded by this chain of events; artists personally reviled, exhibitions withdrawn and under attack, the NEA budget threatened, all because of a few images. For conservative politicians, the NEA debate was not only a battle over the public funding of art, but a war over a larger social agenda, a war for "American values and cultures"based on the family, Christianity, the English language, and patriarchy. Conservative politicians argued the question was not one of "censorship" but of "sponsorship," since the NEA charter committed it to "helping museums better serve the citizens of the United States."Liberals and art communities argued that the attempt to restrict NEA funding violated the First Amendment rights of artists, namely "free speeches." "No matter how divided individuals are on matters of taste," Arthur C. Danto wrote, "freedom is in the interest of every citizen." The interesting phase is that both sides are actually borrowing one another's point of view when they are accompanied by art criticism. Kramer, representative of conservative art critic, objected the invasion of political contents or values in art, and struggled to keep art's own realm by promoting pure aesthetic values such as quality and beauty. But, when he talked about Mapplethorpe's works, he advocated political and ethical values. By contrast, art experts who argued for Mapplethorpe's works in the Cincinnati trial defended his work, ironically by ignoring its manifest sexual metaphor or content although they believed that the issues of AIDS and homosexuality in his work were to be freely expressed in the art form. They adopted a formalistic approach, for example, by comparing a child nude with putti, a traditional child-angel icon. For a while, NEA debates made art institutions, whether consciously or unconsciously, exert self-censorship, yet at the same time they were also producing positive aspects. To the majority of people, art was still regarded as belonging to the pure aesthetic realm away from political, economical, and social ones. These debates, however, were expanding the very perspective on the notion of what is art and of how art is produced, raising questions on art appreciation, representation, and power. The interesting fact remains: had the works not been swiped in NEA debates, could the Serrano's or Mapplethorpe's images gain the extent of power and acceptance that it has today?

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The Causes of Reoperation after Meniscectomy of the Lateral Discoid Meniscus (원판형 연골 절제술 후 재수술의 원인)

  • Lim, H.C.;Shim, J.H.;Ha, H.S.
    • Journal of the Korean Arthroscopy Society
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    • v.3 no.2
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    • pp.115-120
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    • 1999
  • Purpose : After the total or partial meniscectomy of the lateral discoid meniscus, many patients complain the residual pain or the recurrent symptoms of the meniscus, and some of them need reoperation. We analyzed the causes of the reoperation after initial meniscectomy. Material & Method : Two hundred seventy three patients with the symptomatic lateral discoid meniscus were treated by arthroscopic meniscectomy between October, 1989 and September, 1998. Of the 273 patients, 69 patients were treated by total meniscectomy and 204 patients were treated by partial meniscectomy. The male to female sex ratio was 1:1.04, and the average of the age was 23.1 years old(from 4 to 59 years old). The reoperation was done in 8 patients, of which 1 was the case of total meniscectomy at the initial operation, and the rest 7 were the case of partial meniscectomy. Results : Of the 8 reoperations, 3 patients recurred the meniscal symptoms within the 3rd week after the initial operation, and 5 patients recurred beyond the 3rd week after the initial operation. Among the 3 patients of carly recurrence, 2 patients showed inadequate sizes of the remnant meniscus, and 1 patient showed posterolateral instability of the remained meniscus. Among the 5 patients of late recurrence, 3 patients showed rerupture of the meniscus, and 2 patients showed associated pathology of degenerative arthritis following osteochondritis dissecans. Conclusions : The reoperation rate after initial meniscectomy of the lateral discoid meniscus was higher in partial meniscectomy than total meniscectomy. During the operation of the lateral discoid meniscus, we must determine the adequate resectional margin, confirm the remnant meniscus by probing, and look for the associated pathologies.

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Studies on the Yeasts for the Brewing of Soy Sauce(2) -Isolation, identification and classification of the yeasts in the soy sauce mash- (간장발효에 관여하는 효모에 관한 연구 (제2보) -간장 덧 중에 생육하는 효모에 대하여-)

  • Lee, Taik-Soo;Lee, Suk-Kun;Shin, Bo-Kyu
    • Applied Biological Chemistry
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    • v.13 no.2
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    • pp.171-180
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    • 1970
  • The yeasts in the soy sauce mash were isolated and identified, and they were classified by coloring with the treatment of TTC(2, 3, 5, triphenyltetrazolium chloride) agar and counted in process of time. The results obtained were as follows: a) The number of ordinary and osmophilic yeasts in 1 ml. of the soy sauce mash showed a tendency to be increased from the mashing to the mature stages and to decrease in the aging stages: $127{\times}10^3$ immediately after mashing, $83{\times}10^3$ 1 month after, $356{\times}10^3$ 3 months after, $1250{\times}10^3$ 6 months after and $65{\times}10^3$ 2 years after mashing in the case of ordinary yeasts, and 0 after mashing, $40{\times}10^3$ 1 month after, $81{\times}10^3$ 3 months after, $358{\times}10^3$ 6 month after and $23{\times}10^3$ 2 years after mashing in the case of osmophilic yeasts. b) 50 strains of yeasts were isolated from the soy sauce mash optionally in process of fermentation period, and they were identified as 7 genera and 18 species: 10 strains of Saccharomyces rouxii, 1 strain of Saccharomyces marxianus, 3 strains of Saccharomyces rosei, 1 strain of Saccharomyces fermentati, 6 strains of Saccharomyces mellis, 1 strain of Saccharomyces acidifaciens, 1 strain of Saccharomyces pastori, 3 strains of Pichia polymorpha, 2 strains of Hansenula anomala, 1 strain of Hansenula saturnus, 2 strains of Hansenula suaveolens, 5 strains of Nadsonia fulvescens, 8 strains of Debaryomyces hasenii, 1 strain of Debaryomyces nicotianae, 1 strain of Debaryomyces kloeckeri, 2 strains of Torulopsis sake, 1 strain of Torulopsis holmii and 1 strain of Candida pelliculasa. c) Distribution of yeasts according to the fermentation period was as follows: i) Saccharomyces rouxii, Saccharomyces marxianus, Saccharoymces rosei, Pichia polymorpha, Debaryomyces hansenii, Torulopsis sake, Candida pelliculosa, Debaryomyces nicotianae, Nadsonia fulvescens, Hansenula suaveolens and Hansenula saturnus were found in the early stages of fermentation. ii) Saccharomyces rouxii, Saccharomyces rosei, Saccharomyces fermentati, Saccharomyces mellis, Saccharomyces pastori, Hansenula anomala, Saccharomyces acidifaciens and Debaryomyces hansenii appeared in the mature stages. iii) Saccharomyces rouxii, Saccharomyces mellis, Nadsonia fulvescenes, Dedaryomyces hansenii, Debaryomyces kloeckeri, Torulopsis sake and Torulopsis holmii were distributed in the aging stages. d) TTC white yeasts were found in abundance in the early stages of fermentation and TTC red yeasts appeared more than 50 per cent in the mature and aging stages. e) The yeasts belonging to Saccharomyces mellis and Saccharomyces pastori were classified as TTC red yeasts, Saccharomyces acidifaciens were reel pink, Hansenula saturnus Debaryomyces kloeckeri, and Torulopsis holmii were pink, Saccharomyces marxianus and Nadsonia fulvescens were white and the others were the same as the description in the previous report. Saccharomyces rouxii ware classified for the most part as TTC red yeasts, and while some of them were red pink. f) Species of yeasts in the soy sauce mash were similar to those in the soy sauce koji, but the latter were not osmophilic and in the former case, the osmophilic yeasts were increased in process of fermentation period.

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Usefulness of serum procalcitonin test for the diagnosis of upper urinary tract infection in children (소아 상부 요로감염의 진단을 위한 혈청 procalcitonin 검사의 유용성)

  • Kim, Dong Wook;Chung, Ju Young;Koo, Ja Wook;Kim, Sang Woo;Han, Tae Hee
    • Clinical and Experimental Pediatrics
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    • v.49 no.1
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    • pp.87-92
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    • 2006
  • Purpose : It is difficult to make a distinction between lower urinary tract infection(UTI) and acute pyelonephritis(APN) during the acute phase of febrile UTI due to nonspecific clinical symptoms and laboratory findings, especially among young children. We measured the serum procalcitonin(PCT) in children with UTI to distinguish between acute pyelonephritis and lower UTI, and to determine the accuracy of PCT measurement compared with other inflammatory markers. Methods : Serum samples were taken from children who admitted with unexplained fever or were suspected of having UTI. 51 children(mean $12.2{\pm}11.4$ months) were enrolled in this study. Leukocyte counts, erythrocyte sedimentation rates(ESR) and C-reactive protein(CRP) were also measured. Renal parenchymal involvement was assessed by $^{99m}Tc$ DMSA scintigraphy in the first 7 days after admission. PCT was measured by immunoluminometric assay. Results : PCT values were significantly correlated with the presence of renal defects in children with UTI(n=16)($5.06{\pm}12.97{\mu}g/L$, P<0.05). However, PCT values were not significantly different between children with UTI without renal damage(n=18) and children without UTI(n=17). Using a cutoff of $0.5{\mu}g/L$ for PCT and 20 mm/hr for ESR, 20 mg/L for CRP, sensitivity and specificity in distinguishing between UTI with and without renal involvement were 81.3 percent and 88.9 percent for PCT 87.5 percent and 72.2 percent for ESR, and 87.5 percent and 55.6 percent for CRP, respectively. Positive and negative predictive values were 86.7 percent and 84.2 percent for PCT and 60.9 percent and 81.8 percent for CRP, respectively. Conclusion : In febrile UTI, PCT values were more specific than CRP, ESR and leukocyte count for the identification of patients who might develop renal defects.

Metabolic syndrome in the overweight and obese adolescents and the impact of obesity on the cardiovascular system (과체중과 비만 청소년에서 대사증후군과 비만이 심혈관에 미치는 영향)

  • Hong, Young Mi;Song, Young Whan;Kim, Hae Soon;Park, Hae Sook;Min, Jung Hae;Jung, Jo Won;Kim, Nam Su;Noh, Chung Il
    • Clinical and Experimental Pediatrics
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    • v.52 no.10
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    • pp.1109-1118
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    • 2009
  • Purpose : Metabolic syndrome (MS), characterized by obesity and insulin resistance, elicits risk factors such as hyperlipidemia, hypertension, and glucose intolerance with additive effects on atherosclerosis, leading to cardiovascular diseases. The purposes of this study were to evaluate the prevalence of MS among overweight and obese adolescents and to investigate the impact of obesity on the cardiovascular system. Methods : In all, 684 adolescents were included in the study. Blood pressure, body mass index (BMI), fasting blood glucose, total cholesterol, triglyceride, low-density-lipoprotein (LDL)-cholesterol, high-density-lipoprotein (HDL)-cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and high-sensitive C-reactive protein (hs-CRP) were measured in the patients with a BMI of >85 percentile. Brachial-ankle pulse wave velocity (BaPWV) and ankle brachial index were measured using Vascular Profiler (VP)-1000. Results : MS was confirmed in 19.5% of the overweight and obese adolescents and 50.8% of the obese adolescents. The systolic and diastolic blood pressure, height, weight, fat mass, %fat, BMI, obesity index, and waist circumference were higher in the overweight and obese adolescents with MS. Moreover, the triglyceride, AST, ALT, and hs-CRP levels were higher, whereas HDL-cholesterol level was significantly lower in this group. The overweight and obese adolescents with MS showed shorter diastolic and systolic times, higher heart rate and BaPWV, and longer E-wave deceleration time by echocardiography. Conclusion : Overweight and obese adolescents showed characteristic MS features such as hypertension and hyperlipidemia. Thus, obese adolescents predisposed to MS should be provided early treatment for obesity.

Analysis of the Relation of the Positive Inotropic Action of Several Cardiotonics and Aconiti Tuber Butanol Fraction to the Frequency of Contraction of Heart Muscle (수축빈도에 따른 수종 강심약물 및 부자 부타놀 분획의 강심효과의 분석)

  • Lim, J.K.;Kim, M.S.;Shin, S.G.;Park, C.W.
    • The Korean Journal of Pharmacology
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    • v.13 no.2
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    • pp.1-9
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    • 1977
  • The effects of extracellular calcium concentrations and several concentration of Aconiti tuber butanol fraction, norepinephrine, ouabain on the force of isometric contraction of isolated atrial preparations obtained from rabbits were determined at $11{\sim}14$ different frequencies of contraction. Qualitatively similar results were obtained in all preparations. In most preparations, rested-state contraction was induced at the range of $120{\sim}400$ seconds stimulation interval. Over the range of intervals from 120 to 10 seconds negative inotropic effect of activation (NIEA) was predominant, so the steady-state contractile force progressively declined. At the intervals of 3 seconds, changes in the cumulated negative and positive isotropic effect of activation (PIEA) practically cancelled each other under steady-state conditions. At the interval from 3 seconds to 0.25 seconds, the additional cumulation of PIEA was greater than that of the NIEA. When the intervals between contractions were shorter than 0.25 seconds, the cumulation of the NIEA was again predominant. The positive inotropic effect of cardiac glycoside resulted at least in large part from increase in the rested-state contraction. No significant effect on the PIEA was found. The decay of the NIEA was apparently greatly accelerated in the presence of high concentration of ouabain, but this may also be a reflection of their action on the state determining the strength of the rested-state contraction. In the case of extracellular calcium concentration increment, the similar results with the ouabain treatment were obtained. Norepinephrine produced more powerful inotropic effect at shorter stimulation interval than long. The rested-state contraction and the decay of the NIEA were not significantly altered in the presence of norepinephrine, but cumulated PIEA and the amount of PIEA produced by each contraction were significantly increased. Aconiti tuber butanol fraction showed similar results with that of norepinephrine. The increment of contractile force at various contraction frequency were dose-responsive in the presence of Aconiti tuber butanol fraction. It is suggested that the positive inotropic effect of Aconiti tuber butanol fraction at various contraction frequency may be due to increase of the cumulation of PIEA and the amount of PIEA produced by each beat.

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Automated-Database Tuning System With Knowledge-based Reasoning Engine (지식 기반 추론 엔진을 이용한 자동화된 데이터베이스 튜닝 시스템)

  • Gang, Seung-Seok;Lee, Dong-Joo;Jeong, Ok-Ran;Lee, Sang-Goo
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.06a
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    • pp.17-18
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    • 2007
  • 데이터베이스 튜닝은 일반적으로 데이터베이스 어플리케이션을 "좀 더 빠르게" 실행하게 하는 일련의 활동을 뜻한다[1]. 데이터베이스 관리자가 튜닝에 필요한 주먹구구식 룰(Rule of thumb)들을 모두 파악 하고 상황에 맞추어 적용하는 것은 비싼 비용과 오랜 시간을 요구한다. 그렇게 때문에 서로 다른 어플 리케이션들이 맞물려 있는 복잡한 서비스는 필수적으로 자동화된 데이터베이스 성능 관리와 튜닝을 필 요로 한다. 본 논문에서는 이를 해결하기 위하여 지식 도매인(Knowledge Domain)을 기초로 한 자동화 된 데이터베이스 튜닝 원칙(Tuning Principle)을 제시하는 시스템을 제안한다. 각각의 데이터베이스 튜닝 이론들은 지식 도매인의 지식으로 활용되며, 성능에 영향을 미치는 요소들을 개체(Object)와 콘셉트 (Concept)로 구성하고 추론 시스템을 통해 튜닝 원칙을 추론하여 쉽고 빠르게 현재 상황에 맞는 튜닝 방법론을 적용시킬 수 있다. 자동화된 데이터베이스 튜닝에 대해 여러 분야에 걸쳐 학문적인 연구가 이루어지고 있다. 그 예로써 Microsoft의 AutoAdmin Project[2], Oracle의 SQL 튜닝 아키텍처[3], COLT[4], DBA Companion[5], SQUASH[6] 등을 들 수 있다. 이러한 최적화 기법들을 각각의 기능적인 방법론에 따라 다시 분류하면 크게 Design Tuning, Logical Structure Tuning, Sentence Tuning, SQL Tuning, Server Tuning, System/Network Tuning으로 나누어 볼 수 있다. 이 중 SQL Tuning 등은 수치적으로 결정되어 이미 존재하는 정보를 이용하기 때문에 구조화된 모델로 표현하기 쉽고 사용자의 다양한 요구에 의해 변화하는 조건들을 수용하기 쉽기 때문에 이에 중점을 두고 성능 문제를 해결하는 데 초점을 맞추었다. 데이터베이스 시스템의 일련의 처리 과정에 따라 DBMS를 구성하는 개체들과 속성, 그리고 연관 관계들이 모델링된다. 데이터베이스 시스템은 Application / Query / DBMS Level의 3개 레벨에 따라 구조화되며, 본 논문에서는 개체, 속성, 연관 관계 및 데이터베이스 튜닝에 사용되는 Rule of thumb들을 분석하여 튜닝 원칙을 포함한 지식의 형태로 변환하였다. 튜닝 원칙은 데이터베이스 시스템에서 발생하는 문제를 해결할 수 있게 하는 일종의 황금률로써 지식 도매인의 바탕이 되는 사실(Fact)과 룰(Rule) 로써 표현된다. Fact는 모델링된 시스템을 지식 도매인의 하나의 지식 개체로 표현하는 방식이고, Rule 은 Fact에 기반을 두어 튜닝 원칙을 지식의 형태로 표현한 것이다. Rule은 다시 시스템 모델링을 통해 사전에 정의되는 Rule와 튜닝 원칙을 추론하기 위해 사용되는 Rule의 두 가지 타업으로 나뉘며, 대부분의 Rule은 입력되는 값에 따라 다른 솔루션을 취하게 하는 분기의 역할을 수행한다. 사용자는 제한적으로 자동 생성된 Fact와 Rule을 통해 튜닝 원칙을 추론하여 데이터베이스 시스템에 적용할 수 있으며, 요구나 필요에 따라 GUI를 통해 상황에 맞는 Fact와 Rule을 수동으로 추가할 수도 었다. 지식 도매인에서 튜닝 원칙을 추론하기 위해 JAVA 기반의 추론 엔진인 JESS가 사용된다. JESS는 스크립트 언어를 사용하는 전문가 시스템[7]으로 선언적 룰(Declarative Rule)을 이용하여 지식을 표현 하고 추론을 수행하는 추론 엔진의 한 종류이다. JESS의 지식 표현 방식은 튜닝 원칙을 쉽게 표현하고 수용할 수 있는 구조를 가지고 있으며 작은 크기와 빠른 추론 성능을 가지기 때문에 실시간으로 처리 되는 어플리케이션 튜닝에 적합하다. 지식 기반 모률의 가장 큰 역할은 주어진 데이터베이스 시스템의 모델을 통하여 필요한 새로운 지식을 생성하고 저장하는 것이다. 이를 위하여 Fact와 Rule은 지식 표현 의 기본 단위인 트리플(Triple)의 형태로 표현된다, 트리플은 Subject, Property, Object의 3가지 요소로 구성되며, 대부분의 Fact와 Rule들은 트리플의 기본 형태 또는 트리플의 조합으로 이루어진 C Condition과 Action의 두 부분의 결합으로 구성된다. 이와 같이 데이터베이스 시스템 모델의 개체들과 속성, 그리고 연관 관계들을 표현함으로써 지식들이 추론 엔진의 Fact와 Rule로 기능할 수 있다. 본 시스템에서는 이를 구현 및 실험하기 위하여 웹 기반 서버-클라이언트 시스템을 가정하였다. 서버는 Process Controller, Parser, Rule Database, JESS Reasoning Engine으로 구성 되 어 있으며, 클라이 언트는 Rule Manager Interface와 Result Viewer로 구성되어 었다. 실험을 통해 얻어지는 튜닝 원칙 적용 전후의 실행 시간 측정 등 데이터베이스 시스템 성능 척도를 비교함으로써 시스템의 효용을 판단하였으며, 실험 결과 적용 전에 비하여 튜닝 원칙을 적용한 경우 최대 1초 미만의 전처리에 따른 부하 시간 추가와 최소 약 1.5배에서 최대 약 3배까지의 처리 시간 개선을 확인하였다. 본 논문에서 제안하는 시스템은 튜닝 원칙을 자동으로 생성하고 지식 형태로 변형시킴으로써 새로운 튜닝 원칙을 파생하여 제공하고, 성능에 영향을 미치는 요소와 함께 직접 Fact과 Rule을 추가함으로써 커스터마이정된 튜닝을 수행할 수 있게 하는 장점을 가진다. 추후 쿼리 자체의 튜닝 및 인텍스 최적화 등의 프로세스 자동화와 Rule을 효율적으로 정의하고 추가하는 방법 그리고 시스템 모델링을 효과적으로 구성하는 방법에 대한 연구를 통해 본 연구를 더욱 개선시킬 수 있을 것이다.

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