• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1300-1307
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• 2007

This study assessed the possible role of different traits in selected plant growth-promoting rhizobacteria (PGPR) for improving wheat growth and yield under natural conditions. Rhizobacteria exhibiting 1-aminocyclopropane-1-carboxylate (ACC)-deaminase activity were isolated and screened for their growth-promoting activity in wheat under axenic conditions. Five isolates belonging to Pseudomonas and one Burkholderia caryophylli isolate that showed promising performances under axenic conditions were selected and characterized for in vitro ACC-deaminase activity, chitinase activity, auxin production, P solubilization, and root colonization. These isolates were then used as inocula for wheat cultivated under natural conditions in pot and/or field trials. Significant increases in root elongation, root weight, tillers per pot, 1,000-grain weight, and grain and straw yields were observed in response to inoculation with PGPR in the pot trials. Inoculation with these PGPR was also effective under field conditions and increased the wheat growth and yield significantly. However, the efficacy of the strains was inconsistent under the axenic, pot, and field conditions. Pseudomonas fluorescens ($ACC_{50}$), which exhibited a relatively high in vitro ACC-deaminase activity, chitinase activity, auxin production, and P solubilization and more intensive root colonization, was the most efficient isolate under the field conditions. Therefore, these results demonstrated that ACC-deaminase activity is an efficient parameter for the selection of promising PGPR under axenic conditions. However, additional traits of PGPR, including auxin production, chitinase activity, P solubilization, and root colonization, are also important for selecting PGPR as biofertilizers.

• KDI Journal of Economic Policy
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• 제28권2호
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• pp.51-96
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• 2006

재정이 경기조절 역할을 수행하기 위해서는 정책의 시점이 적절해야 하고, 정책의 효과가 유의미해야 한다. 본 연구는 재정정책기조와 경기환경의 상관관계를 고찰함으로써 위의 첫 번째 조건인 정책시점의 적절성을 평가한다. 이를 위해 본 연구는 한국은행 "조사통계월보"의 분기별 재정수지 자료와 추정된 잠재 GDP를 바탕으로 재정충격지수(Fiscal Impulse: FI)를 계산하였다. 이를 이용하여, 첫째 재정충격지수가 GDP 갭으로 대변되는 경기상황에 어떻게 대응하는지를 회귀식을 통하여 분석하고, 둘째 통계청의 경기순환주기에 따라 이 지표의 평균값을 비교하며, 셋째 각 연도의 예산제안서를 검토하여 재정당국의 경기 판단의 적절성과 정책의도의 실현을 평가하였다. 회귀분석 결과는 재정정책, 특히 지출측면이 경기 대응적(counter-cyclical)이었음을 보여주나, 경기순환주기에 따른 지표의 평균값은 경기 상승기와 하강기에 유의미한 차이를 보여주지 못하여, 전체적으로 재정정책이 경기 대응적인 모습을 보였는지에 대한 확정적인 결론을 내리기는 힘들다. 예산제안서를 검토한 결과, 재정의 경기 대응도는 정부의 경기 인식 및 정책의도와 사뭇 다르게 나타날 때도 있어 재정정책을 경기조절을 위하여 적극적으로 사용하기가 어려움을 보여준다.

• 한국추진공학회지
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• 제20권3호
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• pp.78-86
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• 2016

본 논문은 가스터빈시스템에서 외부 유량의 섭동과 이에 따른 열발생의 섭동 사이의 관계를 표현하는 새로운 형태의 화염전달함수(flame transfer function))를 제안한다. 연소의 불안정성을 예측하기 위하여 그 동안 널리 이용되어 왔던 $n-{\tau}$ 모델과 본 논문에서 제안하는 모델과의 가장 큰 차이점은 주파수 변화에 따른 위상의 비선형적인 관계를 표현 할 수 있다는 점에 있다. 기존의 $n-{\tau}$ 모델의 경우 위상은 항상 주파수의 선형함수로 주어지는데 이는 실제 연소시스템의 실험에서 자주 관측되는 결과와 일치하지 않았다. 실험 결과를 바탕으로 새로운 화염전달함수 모델을 구성하였고 연소불안정성의 측면에서 위상의 비선형성이 미치는 영향에 관하여 분석하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1285-1292
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• 2014

An in vitro experiment was conducted to evaluate the effects of Aspergillus oryzae culture (AOC) and 2-hydroxy-4-(methylthio)-butanoic acid (HMB) on rumen fermentation and microbial populations between different roughage sources. Two roughage sources (Chinese wild rye [CWR] vs corn silage [CS]) were assigned in a $2{\times}3$ factorial arrangement with HMB (0 or 15 mg) and AOC (0, 3, or 6 mg). Gas production (GP), microbial protein (MCP) and total volatile fatty acid (VFA) were increased in response to addition of HMB and AOC (p<0.01) for the two roughages. The HMB and AOC showed inconsistent effects on ammonia-N with different substrates. For CWR, neither HMB nor AOC had significant effect on molar proportion of individual VFA. For CS, acetate was increased (p = 0.02) and butyrate was decreased (p<0.01) by adding HMB and AOC. Increase of propionate was only occurred with AOC (p<0.01). Populations of protozoa ($p{\leq}0.03$) and fungi ($p{\leq}0.02$) of CWR were differently influenced by HMB and AOC. Percentages of F. succinogenes, R. albus, and R. flavefaciens (p<0.01) increased when AOC was added to CWR. For CS, HMB decreased the protozoa population (p = 0.01) and increased the populations of F. succinogenes and R. albus ($p{\leq}0.03$). Populations of fungi, F. succinogenes (p = 0.02) and R. flavefacien (p = 0.03) were increased by adding AOC. The HMB${\times}$AOC interactions were noted in MCP, fungi and R. flavefacien for CWR and GP, ammonia-N, MCP, total VFA, propionate, acetate/propionate (A/P) and R. albus for CS. It is inferred that addition of HMB and AOC could influence rumen fermentation of forages by increasing the number of rumen microbes.

• The Korean Journal of Pain
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• 제22권3호
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• pp.229-233
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• 2009

Background: Sacroiliac (SI) joint pain is a challenging condition that causes lower back or buttock pain; however, there is no universally accepted long-term treatment. There have been several reports of ligament prolotherapy for SI joint pain, but these have had inconsistent results, probably due to the lack of a specific diagnosis for patient selection and variability in the volume, number and sites of injection. Therefore, this study was conducted to assess the efficacy of intraarticular prolotherapy for relieving SI joint pain diagnosed by local anesthetic intraarticular injection. Methods: Twenty-two patients with SI joint pain confirmed by 50% or more improvement in response to local anesthetic block underwent intraarticular prolotherapy with 25% dextrose water every other week three times. The numeric rating scale (NRS) for pain and Oswestry disability index (ODI) were assessed at the initial visit and after completion of a series of prolotherapy and the NRS was checked during monthly follow-up sessions to evaluate the long-term effectiveness of this technique. Results: Twenty patients completed prolotherapy and followed up as scheduled. The NRS and ODI were significantly improved from 6 (4-8) and $34.1{\pm}15.5$ to 1 (0-3) and $12.6{\pm}9.8$ (P < 0.01), respectively, at 1 month after prolotherapy. The mean duration of pain relief of 50% or more was 12.2 months (95% CI, 10.0-14.3) as determined by Kaplan-Meier survival analysis. Conclusions: Intraarticular prolotherapy provided long-term relief of sacroiliac joint pain and may have more benefits than ligament prolotherapy or neurolysis.

• The Korean Journal of Physiology and Pharmacology
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• 제21권1호
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• pp.91-97
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• 2017

Hyperglycemia is associated with an increased risk of cardiovascular diseases. It has been demonstrated that chronic exposure to high glucose impaired endothelial functions. However, specific effects of short-term exposure to high glucose on vascular reactivity are controversial. Moreover, the combined effects of other metabolic substrates such as free fatty acids (FFA) on vascular reactivity remain poorly understood. Here we investigate the effects of short-term exposure to high glucose with or without other metabolic substrates including FFAs termed "nutrition full" (NF) solution, on mesenteric (MA) and deep femoral arteries (DFA) of rats. Arterial ring segments were mounted in a double-wire myograph. Contraction in response to phenylephrine (PhE) was determined in control (5 mM) and high glucose (23 mM, HG) environments over a 30 min period. In both arteries, PhE-inducedvasocontraction was enhanced by pre-incubation of HG solution. A combined incubation with HG and palmitic acid ($100{\mu}M$) induced similar sensitization of PhE-contractions in both arteries. In contrast, high $K^+$-induced contractions were not affected by HG. Interestingly, pre-incubation with NF solution decreased PhE-induced contraction in MA but increased the contraction in DFA. In NF solution, the HG-induced facilitation of PhE-contraction was not observed in MA. Furthermore, the PhE-induced contraction of DFA was attenuated by HG in NF solution. Our results demonstrate that the sensitization of PhE-induced arterial contraction by HG is differentially affected by other metabolic substrates. The conversation of skeletal arterial contractility by HG in NF solution requires careful interpretation of the previous in vitro studies where only glucose is included in physiological salt solutions. Further studies are required to elucidate the mechanism underlying the inconsistent effect of NF solution on MA and DFA.

• Journal of Periodontal and Implant Science
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• 제44권1호
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• pp.39-47
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• 2014

Purpose: Peri-implantitis, a clinical term describing the inflammatory process that affects the soft and hard tissues around an osseointegrated implant, may lead to peri-implant pocket formation and loss of supporting bone. However, this imprecise definition has resulted in a wide variation of the reported prevalence; ${\geq}10%$ of implants and 20% of patients over a 5- to 10-year period after implantation has been reported. The individual reporting of bone loss, bleeding on probing, pocket probing depth and inconsistent recording of results has led to this variation in the prevalence. Thus, a specific definition of peri-implantitis is needed. This paper describes the vast variation existing in the definition of peri-implantitis and suggests a logical way to record the degree and prevalence of the condition. The evaluation of bone loss must be made within the concept of natural physiological bony remodelling according to the initial peri-implant hard and soft tissue damage and actual definitive load of the implant. Therefore, the reason for bone loss must be determined as either a result of the individual osseous remodelling process or a response to infection. Methods: The most current Papers and Consensus of Opinion describing peri-implantitis are presented to illustrate the dilemma that periodontologists and implant surgeons are faced with when diagnosing the degree of the disease process and the necessary treatment regime that will be required. Results: The treatment of peri-implantitis should be determined by its severity. A case of advanced peri-implantitis is at risk of extreme implant exposure that results in a loss of soft tissue morphology and keratinized gingival tissue. Conclusions: Loss of bone at the implant surface may lead to loss of bone at any adjacent natural teeth or implants. Thus, if early detection of peri-implantitis has not occurred and the disease process progresses to advanced peri-implantitis, the compromised hard and soft tissues will require extensive, skill-sensitive regenerative procedures, including implantotomy, established periodontal regenerative techniques and alternative osteotomy sites.

• Clinical and Experimental Pediatrics
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• 제56권9호
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• pp.369-376
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• 2013

A complex interplay between genetic and environmental factors partially contributes to the development of allergic diseases by affecting development during prenatal and early life. To explain the dramatic increase in the prevalence of allergic diseases, the hygiene hypothesis proposed that early exposure to infection prevented allergic diseases. The hygiene hypothesis has changed to the microbial hypothesis, in which exposure to microbes is closely linked to the development of the early immune system and allergic diseases. The intestinal flora may contribute to allergic disease through its substantial effect on mucosal immunity. Based on findings that exposure to microbial flora early in life can change the Th1/Th2 balance, thus favoring a Th1 cell response, probiotics may be beneficial in preventing allergic diseases. However, evidence from clinical and basic research to prove the efficacy of probiotics in preventing allergy is lacking. To date, studies have yielded inconsistent findings on the usefulness of probiotics in allergic diseases. It is difficult to demonstrate an exact effect of probiotics on asthma, allergic rhinitis, and food allergy because of study limitations, such as different first supplementation period, duration, different strains, short follow-up period, and host factors. However, many studies have demonstrated a significant clinical improvement in atopic dermatitis with the use of probiotics. An accurate understanding of the development of human immunity, intestinal barrier function, intestinal microbiota, and systemic immunity is required to comprehend the effects of probiotics on allergic diseases.

• 지적과 국토정보
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• 제47권2호
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• pp.121-133
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• 2017

그간 국내의 공간정보 기술기준은 개발, 관리가 하나의 기관이 아닌 다양한 기관에서 진행되어 표준 및 기술기준 간의 중복제정 및 내용 불일치 등의 다양한 문제가 지속적으로 발생되어져 왔다. 이러한 문제들은 단기간이 아닌 장기간 지속적으로 발생하였으며, 이를 해결하고자 그간 다양한 연구들이 진행되어져 왔으나 결국 근본적으로 해결되지 않았다. 하지만 현재 국내의 상황은 국가기술표준원의 '범부처 참여형 국가표준운영체계'을 통해 체계적이고 일원화된 표준체계 구축이 요구되는 환경으로 변모하고 있으며, 이와 관련하여 국토교통부는 국가공간정보 표준 선순환체계인 'KSDI 표준 체계'를 구축하였다. 본 논문에서는 이러한 흐름에 맞춰 그간 지적받아온 기술기준과 관련된 다양한 한계점들을 해결하기 위해, 기존 연구에 대한 고찰을 통해 기술기준의 문제점들을 살펴보았으며, 이에 대한 해결방안으로 기술기준의 재정의, 표준과 기술기준의 관계모델, 상호운용, 관리방안의 측면에서 그 방법을 정리하고 제시하였다.

• 자원ㆍ환경경제연구
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• 제14권1호
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• pp.1-24
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• 2005

진술선호법 연구의 질을 좌우하는 결정적인 요소 중의 하나는 설문지 디자인이다. 본 연구는 Choice Experiments(속성가치선택법) 연구결과의 합리성을 제고함과 아울러 타당성을 검정하기 위한 기술적인 방법으로서 선택질문(choice questions)과 유사한 '예제'를 이용하는 방법에 관하여 논한다. 라돈(radon) 방사능 저감에 대한 지불의사 추정 사례를 이용하였다. 비합리적인 응답을 가려내기 위한 '예제' 디자인을 이용한 사례에서, 설문지 디자인에 관하여 논한 후 한다. 비합리적 응답의 색출 및 제거는 모형의 설명력 증대를 가져왔다. 한편 설문디자인의 영향을 직접적으로 받는 발산적(divergent) 타당성은 닻효과(anchoring effect) 검증을 중심으로 논하였다. 예제의 내용을 기술적으로 디자인하여 두 부차표본들을 만들고 이에 대한 추정모형들간의 동질성을 평가함으로써 닻효과를 검증하였다. 다양한 닻효과 검증 결과는 혼재되었다. 예제 디자인의 장단점에 대해서도 논하였다.