• Animal cells and systems
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• 제3권3호
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• pp.311-317
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• 1999

Prolactin (PRL) was reported to be locally synthesized in many brain areas including the hypothalamus, thalamus (TH) and hippocampus (HIP). In the pituitary lactotrophs, PRL synthesis is dependent upon a pituitary-specific transcription factor, Pit-1. In the present study, we attempted to identify Pit-1 or Pit-1-like protein in brain areas known as the synthetic sites of PRL. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis showed the same Pit-1 transcripts in brain areas such as the medial basal hypothalamus (MBH), preoptic area (POA), TH, and HIP with the Pit-1 transcripts in the anterior pituitary (AP). Electrophoretic mobility shift assay (EMSA) was run with nuclear protein extracts from brain tissues using a double strand oligomer probe containing a putative Pit-1 binding domain. Shifted bands were found in EMSA results with nuclear proteins from MBH, POA, TH and HIP. Specific binding of the Pit-1-like protein was further confirmed by competition with an unlabeled cold probe. Antisense Pit-1 oligodeoxynucleotide (Pit-1 ODN), which was designed to bind to the Pit-1 translation initiation site and block Pit-1 biosynthesis, was used to test Pit-1 dependent brain PRL transcription. Two nmol of Pit-1 ODN was introduced into the lateral ventricle of a 60-day old male rat brain. RNA blot hybridization and in situ hybridization indicated a decrease of PRL mRNA signals by the treatment of Pit-1 ODN. Taken together, the present study suggests that Pit-1 may play an important role in the transcriptional regulation of local PRL synthesis in the brain.

• 한국지능시스템학회논문지
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• 제10권2호
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• pp.138-145
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• 2000

본 본문에서는 퍼지모델의 최적 입, 출력 소속함수들(membership functions) 및 규칙기반(rulebase) 얻기 위한 동정 알고리즘을 제안하였다. 제안된 알고리즘에서 구륜이동로봇(WMR)의 위치 속도 방향제어를 위한 퍼지제어기를 설계하였다 제안된 알고리즘에서 입,출력 소속함수의 파라미터들을 찾기위하여 유전알고리즘을 응용한다. 유전알고리즘에 의해 출력술어의 원소가 증가되면 규칙기반이 원소의 증가에 의하여 조절된다. 새롭게 조절된 퍼지시스템은 풀력술어의 증가를 수행하지 않은 시스템과 경쟁하며 만약 새롭게 조절되어진 퍼지시스템이 경쟁에서 진다면 그 시스템은 소멸한다. 그 반대로 조절된 시스템이 생존한다면 출력술어의 증가된 각 원소들 및 변화된 시스템의 규칙기반이 퍼지제어기에 적용된다. 출력술어 및 규칙의 조절이 완료된 후 입력 소속함수들에 대한 탐색이 제약 조건을 가지고 수행되며 입력소속함수들의 탐색이 완료된 후 출력소속함수의 미세조정이 수행된다. 제안된 알고리즘을 적용하여 구륜 이동로봇의 위치, 속도, 방향, 제어를 위한 제어기를 설계하여 실험한 결과 그 유효성을 입증하였다.

• 에너지공학
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• 제5권2호
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• pp.93-107
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• 1996

본 연구는 가스산업 조직과 규제 정책을 중심으로, 주요선진국들과 국내의 가스산업을 비교한 것이다. 그리하여, 우리나라와 미국, 캐나다, 영국, 프랑스, 독일 및 일본의 천연가스 산업 구조와 규제현황, 성장과정 등을 비교·분석하였고, 그 결과는 다음과 같다. 첫째, 가스산업이 성숙된 국가들은 상류부문과 최종소비자 보급부문의 시장경쟁을 촉진하려는 것이 최근의 추세이다. 그러나, 현재 우리나라는 도시가스 최종판매부분이 완전 민영화되어 있는데, 그러면서도 전국적 배관망이 완성되지 않아, 제 3자 수송을 통한 도시가스 보급경쟁의 조장은 아직 이르다고 할 수 있으며, 수요 급성장에 대응하여 안정적인 공급기반을 구축하는 것이 우선적인 정책과제라 본다. 둘째, 지금과 같은 LNG 형태의 도입 계약 확대와 더불어, 파이프라인을 통한 가스도입 방법의 모색과 도입선 다변화 등 적극적 자원확보 방안이 검토되어야 한다. 셋째, 비교 대상국들의 가스관련 기술개발이 대외 공여수준에 이르는데 반해 우리나라에서는 아직 미약한 실정이므로, 가스기슬의 개발과 자립기술을 바탕으로 한 해외사업 진출 등 부가가치를 더욱 증대시킬 수 있는 영역으로의 사업다각화가 필요하다.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.159-167
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• 1994

The contraction of rabbit basilar artery was examined as a function of changes in the $Na^+$ electrochemical gradient in order to determine the contribution of $Na^+/Ca^{2+}$ exchange to the modulation of contractility. Ouabain $(10^{-5}\;M)$ or $K^+-free$ Tyrode solution caused an increase in tonic tension even in the presence of a $Ca^{2+}$ channel blocker $(10^{-6}\;M\;verapamil)$ and an ${\alpha}-receptor$ blocker $(10^{-5}\;M\;phentolamine)$. After treatment with ouabain $(10^{-5}\;M)$, contractions were augmented by reduction of external $Na^+$ concentration. The longer the treatment with ouabain $(10^{-5}\;M)$ was, the larger the amplitude of $Na^+-free$ contracture was. $Na^+-free$ contracture wag induced by either substitution of equimolar Tris for $Na^+$ or substitution of equimolar $Li^+\;for\;Na^+$. The competition between $Na^+\;and\;Ca^{2+}$ for the $Na^+/Ca^{2+}$ exchange carrier would exist, because it was observed that contractility was dependent on the $Na^+$ electrochemical gradient or the extracellular $Ca^{2+}$ concentration (2 mM, 4 mM). Ryanodine $(10^{-7}\;M)$, the blocker of intracellular $Ca^{2+}$ release from the sarcoplasmic reticulum, did not suppress the development of $Na^+-free$ contracture. The contractile response to norepinephrine $(10^{-6}\;M)$ was augmented by reducing the extracellular $Na^+$ concentration. The relaxation rate from caffeine-induced contraction was dependent on the extracellular $Na^+$ concentration (0 mM, 140 mM). From the above results, it could be suggested that $Na^+/Ca^{2+}$ exchange can move $Ca^{2+}$ either into or out of rabbit basilar arterial smooth muscle. $Ca^{2+}$ entry or extrusion is dependent upon the $Na^+$ electrochemical gradient. $Na^+/Ca^{2+}$ exchange plays a significant role in the regulation of contractility in rabbit basilar arterial smooth muscle.

• BMB Reports
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• 제29권2호
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• pp.175-179
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• 1996

Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.

• 무역상무연구
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• 제19권
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• pp.7-31
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• 2003

The governments of almost countries have the rules and procedures that the purchasing entities have to follow, in order to ensure that the best value for money spent is obtained in procuring goods and services. However, there are often some of important problems in their rules relating to government procurement. Namely, almost countries have a variety of discriminatory regulations for foreign suppliers in the government procurement laws with the object of national security, economic welfare, and protection of domestic market from international competition. For this reason, several advanced countries had reached the Plurilateral Agreement on Government Procurement during Tokyo Round(1973-1979) and Uruguay Round(1986-1994). However, the provisions of two agreements do not apply to all products made by the government but only to those made by purchasing entities specified by each member country in its list in the Appendix. Accordingly, the size of goods and services purchased from foreign suppliers were comparatively not large. As we know well, the United States have spent a large amount of money from federal and state government budget. But the portion of procurement from foreign suppliers is still small, compared with the portion of procurement from domestic suppliers. The main reason are that U.S. has applied for long time the so-called Buy American Act to government procurement positively and maintained many kinds of other domestic regulations which have discriminatory provisions for foreign goods and foreign suppliers. On the recognition of these points, this thesis deals with the Buy American Act and other U.S. domestic laws, regional and bilateral, and plurilateral agreements including WTO Agreement on Government Procurement. As a result, the author found that there are several concerns and problems in the U.S. regulations relating to government procurement. It include the provisions on priority procurement of U.S.-produced products, local contents requirements, set-aside procurement from small business, and exclusion of preferential procurement from the developing countries.

• 한국콘텐츠학회논문지
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• 제13권8호
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• pp.360-370
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• 2013

2000년대 초반 이동통신서비스 시장의 급속한 성장에 따라 유선망에서 이동망으로 상호접속 수요가 증가하면서 유선망사업자와 무선망사업자 간의 공정한 상호접속 관계를 위한 제도가 도입되었으며, 이동전화보급률이 90%를 넘어선 2000년대 중반부터는 이동망 사업자간 상호접속 문제가 대두되었고 현재에는 인터넷 전화, LTE, 스마트폰 등의 보급으로 상호접속의 대상이 더욱 복잡해졌다. 본 논문에서는 2000년대 초반 이동망착신(LM) 접속료가 유선 및 이동전화서비스 사업자들간의 경쟁에 중요한 요소가 되었던 점에 착안하여 당시의 자료를 바탕으로 국내 이동망착신 접속료의 수준을 36개 해외 국가들과 비교해보고 함의를 구하고자 하였다. 이를 위해 상관분석과 회귀분석을 통해 접속료 수준에 대한 각 국가별 인구, 1인당 GDP, 이동통신시장에 대한 규제여부, 요금부과 방식, 유선전화보급율, 무선전화보급률 등의 변수가 이동망착신 접속료 수준 결정에 유의한 영향을 미치는지를 확인하고자 하였다.

• Nutrition Research and Practice
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• 제9권4호
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• pp.343-349
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• 2015

BACKGROUND/OBJECTIVES: Fermentation of dietary fiber results in production of various short chain fatty acids in the colon. In particular, butyrate is reported to regulate the physical and functional integrity of the normal colonic mucosa by altering mucin gene expression or the number of goblet cells. The objective of this study was to investigate whether butyrate modulates mucin secretion in LS174T human colorectal cells, thereby influencing the adhesion of probiotics such as Lactobacillus and Bifidobacterium strains and subsequently inhibiting pathogenic bacteria such as E. coli. In addition, possible signaling pathways involved in mucin gene regulation induced by butyrate treatment were also investigated. MATERIALS/METHODS: Mucin protein content assay and periodic acid-Schiff (PAS) staining were performed in LS174T cells treated with butyrate at various concentrations. Effects of butyrate on the ability of probiotics to adhere to LS174T cells and their competition with E. coli strains were examined. Real time polymerase chain reaction for mucin gene expression and Taqman array 96-well fast plate-based pathway analysis were performed on butyrate-treated LS174T cells. RESULTS: Treatment with butyrate resulted in a dose-dependent increase in mucin protein contents in LS174T cells with peak effects at 6 or 9 mM, which was further confirmed by PAS staining. Increase in mucin protein contents resulted in elevated adherence of probiotics, which subsequently reduced the adherent ability of E. coli. Treatment with butyrate also increased transcriptional levels of MUC3, MUC4, and MUC12, which was accompanied by higher gene expressions of signaling kinases and transcription factors involved in mitogen-activated protein kinase (MAPK) signaling pathways. CONCLUSIONS: Based on our results, butyrate is an effective regulator of modulation of mucin protein production at the transcriptional and translational levels, resulting in changes in the adherence of gut microflora. Butyrate potentially stimulates the MAPK signaling pathway in intestinal cells, which is positively correlated with gut defense.

• 한국콘텐츠학회논문지
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• 제18권5호
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• pp.167-174
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• 2018

일본정부는 급격하게 고령화 되어가는 사회에 대응하기 위해 지속적으로 노인복지를 확대해왔다. 그리고 일본의 노인 복지제도의 바탕을 이루고 있던 조치제도는 2000년에 들어서면서 개호보험이라는 사회보험적 형태의 노인복지 시스템으로 변화, 정착되었고 일본의 노인복지 시스템은 획기적인 변화를 맞게 되었다. 본 연구에서는 이러한 개호보험이 가지는 주요 특징 중에 특별히 주목하는 점은 다음과 같다. 첫째, 개호보험은 사회보험시스템으로서 의무적인 가입을 해야 하며 상당한 양의 보험금과 자기부담금을 부담해야한다. 둘째, 복지제도의 이용자는 소비자로 인식되며, 그들은 다양한 소비자로서의 초이스를 가질 수 있도록 하고, 이를 위해 복지서비스 제공자는 자유시장에서의 경쟁의 원리를 바탕으로 활동하게 된다. 그리고 이전의 조치제도 하의 복지서비스 제공자들이 정부 주도의 시설과 단체들로서 그에 대한 규제가 엄격하였다면, 개호 보험에서의 서비스 제공자들은 훨씬 유화되고 간단해진 관리와 규제를 받게 되었다. 이러한 개호보험의 특징은 재일조선, 한국인 조직들이 재일 고령자라는 소비자에게 일본 복지서비스에서는 찾기 힘든 한민족의 민족적 콘텐츠를 노인 복지 영역에 도입하는 활동을 기획하고 실천하는데 있어 그 동력을 제공하였다. 즉, 한민족 콘텐츠를 복지 서비스의 판매에 유리한 조건(selling point)로서, 동시에 예상되는 복지이용에서의 민족적 불이익에 대한 대안으로 삼음으로써 일본의 노인복지서비스 영역을 다양화하는 결과를 가져왔다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.114-114
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• 2018

Among the various volatile organic compounds (VOCs) emitted by the plant, floral scent plays a key role in attracting pollinators for reproduction and mediates ecological interactions. Floral scent is an important trait and industry drives the competition for flowers with novel scents. Chrysanthemum is one of the well-known ornamental plants and is a popular cut flower across the world. Floral scent and the genes responsible for the floral scent emission are poorly studied in chrysanthemum. In the present study, floral scent and the expression pattern of floral scent genes were analyzed in two chrysanthemum cultivars 'Golden Egg' and 'Gaya Glory'. Initially, intensity of the floral scent in five developing stages of flower including 'budding (B), bud developing (BD), initial blooming (IB), almost open (AO) and open flower (OF)' was analyzed using electronic nose (E-nose) with six metal oxide sensors. Based on the distance analysis, different stages of flower showed different relative intensity of scent according to the sensory evaluation. Although the scent pattern differed by stage, scent intensity was strongest in the OF stage in the completely opened flower in both the cultivars. Further, expression pattern of six genes in the floral scent pathway including FDS, IDI, ISPH, TPS2, TPS5 and TPS6 was observed in all the five stages of the flower in both the cultivars. The expression pattern of all the six genes differed by stage and the terpene synthase genes TPS2, TPS5 and TPS6 showed good expression levels in the $5^{th}$ flower stage compared to other stages. This study provides a preliminary data for understanding the regulation of floral scent in chrysanthemum.