• 제목/요약/키워드: life-cycle hypothesis

검색결과 34건 처리시간 0.023초

Observational Evidence of Giant Cloud Condensation Nucleus Effects on the Precipitation Sensitivity in Marine Stratocumulus Clouds

  • Jung, Eunsil
    • 한국지구과학회지
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    • 제43권4호
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    • pp.498-510
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    • 2022
  • Cloud-aerosol interactions are one of the paramount but least understood forcing factors in climate systems. Generally, an increase in the concentration of aerosols increases the concentration of cloud droplet numbers, implying that clouds tend to persist for longer than usual, suppressing precipitation in the warm boundary layer. The cloud lifetime effect has been the center of discussion in the scientific community, partly because of the lack of cloud life cycle observations and partly because of cloud problems. In this study, the precipitation susceptibility (So) matrix was employed to estimate the aerosols' effect on precipitation, while the non-aerosol effect is minimized. The So was calculated for the typical coupled, well-mixed maritime stratocumulus decks and giant cloud condensation nucleus (GCCN) seeded clouds. The GCCN-artificially introduced to the marine stratocumulus cloud decks-is shown to initiate precipitation and reduces So to approximately zero, demonstrating the cloud lifetime hypothesis. The results suggest that the response of precipitation to changes in GCCN must be considered for accurate prediction of aerosol-cloud-precipitation interaction by model studies

A Novel Approach to Investigating Protein/Protein Interactions and Their Functions by TAP-Tagged Yeast Strains and its Application to Examine Yeast Transcription Machinery

  • Jung, Jun-Ho;Ahn, Yeh-Jin;Kang, Lin-Woo
    • Journal of Microbiology and Biotechnology
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    • 제18권4호
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    • pp.631-638
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    • 2008
  • Tandem affinity purification (TAP) method combined with LC-MS/MS is the most accurate and reliable way to study the interaction of proteins or proteomics in a genome-wide scale. For the first time, we used a TAP-tag as a mutagenic tool to disrupt protein interactions at the specific site. Although lots of commonly used mutational tools exist to study functions of a gene, such as deletional mutations and site-directed mutagenesis, each method has its own demerit. To test the usefulness of a TAP-tag as a mutagenic tool, we applied a TAP-tag to RNA polymerase II, which is the key enzyme of gene expression and is controlled by hundreds of transcription factors even to transcribe a gene. Our experiment is based on the hypothesis that there will be interrupted interactions between Pol II and transcription factors owing to the TAP-tag attached at the C-terminus of each subunit of Pol II, and the abnormality caused by interrupted protein interactions can be observed by measuring a cell-cycle of each yeast strain. From ten different TAP-tagged strains, Rpb7- and Rpb12-TAP-tagged strains show severe defects in growth rate and morphology. Without a heterodimer of Rpb4/Rpb7, only the ten subunits Pol II can conduct transcription normally, and there is no previously known function of Rpb7. The observed defect of the Rpb7-TAP-tagged strain shows that Rpb7 forms a complex with other proteins or compounds and the interruption of the interaction can interfere with the normal cell cycle and morphology of the cell and nucleus. This is a novel attempt to use a TAP-tag as a proteomic tool to study protein interactions.

만성 질환이 자아개념 (Self Concept)과 신체상(Body Image)에 미치는 영향 -천식 환아를 중심으로- (A Study of the Influence of illness on Body Image and Self Concept -Specifically in Children with Asthma-)

  • 장효순
    • 대한간호학회지
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    • 제12권2호
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    • pp.80-90
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    • 1982
  • This study was undertaken to determine the influence of a chronic disease on body image, and to show that body image is directly related to one's self concept. Body image is the concept of one's own body based on present and past perception, and is elated to one's self concept. Body image is a dynamic concept constantly changing throughout the life cycle but it changes greatly in illness, surgery, and accident. The child with a chronic disease experiences pain and immobilization due to illness and he/she experiences a strange environment in the hospital. illness often brings feeling of frustration and loss of self-esteem. Therefore this study was done to compare the body image of a child with a chronic disease(Asthma), with that of a normal healthy child, and to determine the relationship between the body image and self concept. The subjects in this study were 36 children being treated for asthma at the allergy clinic of Y University Hospital in Seoul (patient group) and 44 children attending elementary school in Kwanak Ku Seoul (normal healthy group). For the measurement of the body image, the researcher used Secord & Jourard's Body Cathexis Scale, and another scale which was constructed after reading about Osgood's Semantic Differential Method. For the measurement of the self concept, the researcher used Jacox & Stewart's Health Self Concept. The period for data collection was from October 7th to October 27th, 1982. The analysis of data was done by use of Percentage, t-test, Chi-square test, Pearson Correlation Coefficient and ANOVA, The results of the study were as follows: 1. The first hypothesis,“That the chronically ill (Asthma) child will have a more negative body image than the normal healthy child.”was supported. 2. The second hypothesis,“The more negative the body image, the lower the self concept.”was also supported. 3. The researcher failed to obtain statistically significant results in the analysis of the general characteristics which affect the body image except in the case of the older child as compare to the younger Child having a mole positive body image (r=.2751, r=.2481, p<.05). However it was found that, 1) Boy's have a more positive body image than girls (Mean=〔37.81, 141.09〕,〔37.00, 126.54〕), 2) The child who has been hospitalized has a more negative body image than the child who has never been hospitalized (Mean=〔33.25, 122.45〕,〔35.68, 129.93〕). 3) The younger the child when the disease is discovered and diagnosed, the more negative the body image (Onset of illness: Mean=〔31.44, 117.33〕,〔34.00, 103.50〕, 〔35.75, 140.38〕,〔36.33, 130.00〕, Time of Diagnosis: Mean=〔29.00, 117.33〕,〔33.89, 115.00〕,〔33.36, 124.93〕,〔37.10, 139. 20〕). In conclusion the chronically ill(.Asthma) child has a more negative body image than the normal healthy child, and the more negative the body image the lower the self concept. Therefore the concept of body image is useful in understanding the influences of chronic disease on body' image and self concept.

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외식소비자의 건강지향 메뉴가 LOHAS와 약선 음식 및 고객만족에 미치는 영향 (Effect of Health-Orientated Menu for Restaurant Customers on LOHAS, Herbal Food, and Customer Satisfaction)

  • 최성웅;진양호
    • 한국조리학회지
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    • 제16권2호
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    • pp.96-109
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    • 2010
  • 라이프사이클의 변화와 외식 인구의 급격한 증가와 함께 외식을 통해 섭취하는 영양소의 불균형이 만성질환의 위험 요인으로 제기되면서, 외식소비자의 건강지향 메뉴는 외식건강산업의 새로운 분야로서 사회적인 이슈가 되고 있다. 이에 본 연구의 목적은 외식소비자의 건강지향 메뉴가 로하스와 약선 음식 그리고 고객만족에 영향을 미치는 관계를 파악하여 로하스와 약선 음식에 대한 유용한 정보를 제공하였으며, 외식소비자의 건강과 밀접한 관련이 있는 채식, 약선 음식, 사찰 음식 등의 레스토랑 고객을 대상으로 탐색해 보았다. 분석결과, 먼저 건강지향성은 로하스에 유의적인 영향을 미치고 있는 것으로 나타났다. 둘째, 건강지향 메뉴는 약선 음식을 매개하여 고객만족에까지 유의적인 정의 영향을 미치고 있는 것으로 분석되었다. 셋째, 로하스는 약선 음식에 유의적인 영향을 미치고 있으며, 약선 음식을 매개로 고객만족에까지 유의적인 정(+)의 영향을 미치고 있는 것으로 분석되었다. 마지막으로 약선 음식은 고객만족에 유의적인 영향을 미칠 것이라는 가설도 유의적인 영향을 미치고 있는 것으로 분석되었다. 따라서 이와 같은 분석결과를 바탕으로 외식소비자의 건강지향 메뉴에 대한 시사점을 제시하였다.

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간암치료신약개발 및 이의 제제화 연구 (Replication of Hepatitis B Virus is repressed by tumor suppressor p53)

  • 이현숙;허윤실;이영호;김민재;김학대;윤영대;문홍모
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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    • pp.178-178
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    • 1994
  • Hepatitis B Virus (HBV) is a DNA virus with a 3.2kb partially double-stranded genome. The life cycle of the virus involves a reverse transcription of the greater than genome length 3.5kb mRNA. This pegenomic RNA contains all the genetic information encoded by the virus and functions as an intermediate in viral replication. Tumor suppressor p53 has previously been shown to interact with the X-gene product of the HBV, which led us to hypothesize that p53 may act as a negative regulator of HBV replication and the role of the X-gene product is to overcome the p53-mediated restriction. As a first step to prove the above hypothesis, we tested whether p53 represses the propagation of HBV in in vitro replication system. By transient cotransfection of the plasmid containing a complete copy of the HBV genome and/or the plasmid encoding p53, we found that the replication of HBV is specifically blocked by wild-type p53. The levels of HBV DNA, HBs Ag and HBc/e Ag secreted in cell culture media were dramatically reduced upon coexpresion of wild-type p53 but not by the coexpression of the mutants of p53 (G154V and R273L). Furthermore, levels of RNAs originated from HBV genome were repressed more than 10 fold by the cotransfection of the p53 encoding plasmid. These results clearly states that p53 is a nesative regulator of the HBV replication. Next, to addresss the mechanism by which p53 represses the HBV replication, we performed the transient transfection experiments employing the pregenomic/core promoter-CAT(Chloramphenicol Acetyl Transferase) construct as a reporter. Cotransfection of wild-type p53 but not the mutant p53 expression plasmids repressed the CAT activity more than 8 fold. Integrating the above results, we propose that p53 represses the replication of HBV specifically by the down-regulation of the pregenomic/core promoter, which results in the reduced DNA synthesis of HBV. Currently, the mechanism by which HBV overcomes the observed p53-mediated restriction of replication is tinder investigation.

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서울시 청년 1인 가구 주거 문제 분석 - 주거소비 면적 감소 현상을 중심으로 - (A Study on The Housing Consumption Problem in Young Single-Person Household - Focusing on Reduction of Housing Area -)

  • 조하은;김의준
    • 지역연구
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    • 제34권1호
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    • pp.49-60
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    • 2018
  • 본 연구의 목적은 청년 1인 가구 증가와 함께 나타나는 주거 문제의 원인을 분석하는 것이다. 본 연구에서는 생애 주기 가설을 기반으로 주택 수요 함수를 추정하였다. 추정 결과, 청년 1인 가구의 주택 수요와 항상소득 잔차로 인한 주택 수요가 다른 집단에 비해 유의미하게 낮게 나타났다. 이는 청년 1인 가구의 주택 소비에 항상소득이 충분히 실현되지 못하고 있으며, 이를 뒷받침할 금융 시장의 역할이 미비함을 의미한다. 본 연구에서는 항상소득 실현의 어려움과 주택 금융 부족을 청년 1인 가구 주택 수요 불균형 현상의 원인으로 분석하였다. 따라서 청년 1인 가구의 주택 문제를 해결하기 위해 항상소득과 현재 주택 수요의 균형을 유도하는 정책이 도입되어야 한다.

한국 이동통신시장에서 서비스품질과 전환장벽이 고객만족과 고객충성도에 미치는 영향 (The Effects of Cellular Phone Service Quality and Switching Barrier to Customer Satisfaction and Loyalty in Korean Mobile Telecommunication Market)

  • 주형률;이진춘
    • 한국IT서비스학회지
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    • 제9권2호
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    • pp.43-72
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    • 2010
  • The Korean mobile telecommunication service market is faced with a tremendous competitive period, in which the market is entering into the maturity stage with launching of the 3rd generation service and with introduction of mobile number portability. In general, it is more important to sustain the old customers than to attracting new customers, as the life cycle of an industry is entering the maturity stage in which the growth rate of new customers is decreasing gradually or becoming stagnant. Until now, many researches had tested whether the customer satisfaction and loyalty were the core factors of sustaining customers or not. Also service quality and switching cost were given a remarkable attention for their possibility of exogenous factors, which could exercise effects to customer satisfaction and loyalty. In the same context, mobile telecommunication business has to seek a way to maintain the existing customers instead of promoting new customers. So this study investigates whether the service quality and switching barrier of mobile telecommunication could have effects on the customer satisfaction and loyalty, which are recognized as an efficient means to sustain the current customers. In order to test the hypothesis on the effects of service quality and switching barrier of mobile telecommunication to customer satisfaction and loyalty in Korean telecommunication industry, this study collected the questionnaire response data of students including middle and high school students and undergraduates, who are regarded as the major customers in that mobile telecommunication industry.

Deficiency of Formyl Peptide Receptor 2 Retards Hair Regeneration by Modulating the Activation of Hair Follicle Stem Cells and Dermal Papilla Cells in Mice

  • Han, Jinsol;Lee, Chanbin;Jung, Youngmi
    • 한국발생생물학회지:발생과생식
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    • 제25권4호
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    • pp.279-291
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    • 2021
  • Hair loss is one of the most common chronic diseases, with a detrimental effect on a patient's psychosocial life. Hair loss results from damage to the hair follicle (HF) and/or hair regeneration cycle. Various damaging factors, such as hereditary, inflammation, and aging, impair hair regeneration by inhibiting the activation of hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). Formyl peptide receptor 2 (FPR2) regulates the inflammatory response and the activity of various types of stem cells, and has recently been reported to have a protective effect on hair loss. Given that stem cell activity is the driving force for hair regeneration, we hypothesized that FPR2 influences hair regeneration by mediating HFSC activity. To prove this hypothesis, we investigated the role of FPR2 in hair regeneration using Fpr2 knockout (KO) mice. Fpr2 KO mice were found to have excessive hair loss and abnormal HF structures and skin layer construction compared to wild-type (WT) mice. The levels of Sonic hedgehog (Shh) and β-catenin, which promote HF regeneration, were significantly decreased, and the expression of bone morphogenetic protein (Bmp)2/4, an inhibitor of the anagen phase, was significantly increased in Fpr2 KO mice compared to WT mice. The proliferation of HFSCs and DPCs was significantly lower in Fpr2 KO mice than in WT mice. These findings demonstrate that FPR2 impacts signaling molecules that regulate HF regeneration, and is involved in the proliferation of HFSCs and DPCs, exerting a protective effect on hair loss.

정부의 기술개발 지원이 중소기업의 기술혁신 성과에 미치는 영향 (The Effect of Government R&D Supports on SME's Technological Innovation Performance in Korea)

  • 이병헌;이수욱;위세안
    • 벤처창업연구
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    • 제9권5호
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    • pp.157-171
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    • 2014
  • 본 연구는 정부의 기술개발 지원이 중소기업의 기술혁신 성과에 미치는 영향에 대해 연구하였다. 정부의 기술개발 지원이 중소기업의 기술혁신 성과에 미치는 영향을 검증하기 위해 271개 국내 중소기업을 대상으로 실증 분석하였다. 분석 결과, 정부 기술개발 지원이 중소기업의 혁신성과에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 한편, 중소기업에 대한 대기업의 지원정도가 높을수록, 중소기업의 R&D 인력비율이 높을수록, 그리고 벤처인증을 받은 중소기업일수록 정부 기술개발 지원이 중소기업의 기술혁신 성과에 미치는 영향은 작아지는 것으로 나타났다. 반면, 중소기업의 시장 환경이 적대적일수록, 정부 지원에 따른 중소기업의 기술혁신 성과는 높아졌다. 본 연구는 동일 기업에 대해 시간적 간격을 두고 두 차례에 걸쳐 자료를 수집, 분석함으로써 정부의 기술개발 지원이 중소기업의 성과에 미치는 영향을 보다 정확하게 분석함으로써 정부당국과 중소기업에 이론적, 실무적 시사점을 제공하였다. 결론에서는 본 연구의 표본 선정절차, 데이터 수집방법, 변수 측정방법 등 전체적인 측면에서 본 연구가 안고 있는 한계점과 향후 연구방향에 대해 논의하였다.

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Computer Aided Innovation 역량이 연구개발역량에 미치는 효과: 국내 중소기업을 대상으로 (The Effects of the Computer Aided Innovation Capabilities on the R&D Capabilities: Focusing on the SMEs of Korea)

  • 심재억;변무장;문효곤;오재인
    • Asia pacific journal of information systems
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    • 제23권3호
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    • pp.25-53
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    • 2013
  • This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.