• Title/Summary/Keyword: dominant effect

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The effect of body lead burden on neurobehavioral function in retired lead workers (퇴직한 납 근로자들의 체내 납 부담 노출지표가 신경행동학적 기능에 미치는 영향)

  • Kim, Nam-Soo;Kim, Jin-Ho;Lee, Byung-Kook
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.20 no.3
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    • pp.156-167
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    • 2010
  • To evaluate the effect of lead biomarkers including bone lead on neurobehavioral test in retired lead workers, 131 retired lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 56 non-occupationally lead exposed subjects were recruited from same area of retired lead workers with consideration of demographic characteristics. The mean levels of blood and bone lead of retired lead workers were significantly higher than control group and there were significant correlation among other lead biomarkers. Compared with controls without occupational lead exposure, lead exposured subjects had worse performance on 10 tests out of 12 neurobehavioral tests, but only two tests(Purdue pegboard nondominant and both hand) showed statistical significance of differences. In multiple linear regression analysis of neurobehavioral tests with lead biomarkers and demographic and lifestyle variables, age was associated negatively with 11 neurobehavioral tests, whereas log-transformed ZPP was associated with Purdue pegboard(both hand) and Santa Ana manual dexterity(non-dominant hand). On the other hand, tibia lead was associated Pursuit aiming test(correct) and Purdue pegboard(dominant hand) and calcaneal lead was associated with Purdue pegboard(dominant hand). This study confirmed that among all relevant variables age was most significantly associated with the poor performance of neurobehavioral tests. The blood lead did not have any significant association with neurobehavioral tests, but tibia and calcaneal bone lead and blood ZPP showed significant association with a few tests even after more than mean 9 years from their retirements.

Changes of Sexual Behaviors in Rapamycin-injected Cichlid Fish Astatotilapia burtoni Males

  • Kim, Tae Ha;Sohn, Young Chang
    • Development and Reproduction
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    • v.20 no.3
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    • pp.267-274
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    • 2016
  • Cichlid fish species exhibit characteristic sexual behaviors according to not only reproductive stages but also social status. In a reproductive season, Astatotilapia burtoni males compete for females and a small number of dominant winners finally obtain the chance of spermiation. In addition to the characteristic behaviors, the dominant males have relatively bigger gonadotropin-releasing hormone 1 (GnRH1) neurons in the preoptic area (POA) of brain compared to those of subordinate males. Although the stimulatory effect of GnRH1 in vertebrate reproduction is well established, little is known about the triggering signal pathway to control GnRH1 neurons and GnRH1-mediated sexual behavior. In the present study, we evaluated the potential effect of TOR inhibitor rapamycin in relation to the cichlid male behaviors and GnRH1 neuron. After 14 h and 26 h of intraventricular injection of rapamycin, behavior patterns of chasing and courtship display did not show significant changes between rapamycin- and DMSO-injected males. Behaviors of spawning site entry increased in rapamycin-injected fish at 26 h post-injection than at 14 h post-injection significantly (P<0.05). Meanwhile, there was a tendency that GnRH1 neurons' soma size in the POA shrank by rapamycin injection, whereas the testes did not show notable changes. Taken together, these results suggest the possible role of TOR signal on GnRH1-mediated sexual behavior in cichlid dominant males, although further biological characterization of the TOR signaling pathway will be required to clarify this matter.

Genetic Analyses on Quantitative Characters of F1 Generation in Malting Barley (맥주맥 F1세대의 양적형질에 대한 유전분석)

  • 정원복;오주성;황필성
    • Journal of Life Science
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    • v.13 no.1
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    • pp.29-33
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    • 2003
  • The study was conducted to get genetic information on quantitative characters of $F_1$ in barley through diallel crosses using seven malting barley. The results obtained were summarized as follows. Additive, dominant, maternal, and reciprocal effort were observed in culm length, spike length, awn length, culm diameter, grain length, grain width, ]lumber of grains per spike, and 1000 grain weight. Based on the Vr-Wr graphical analysis, culm length, spike length, awn length, grain length, and number of grains per spike were found to be inherited over dominance. Dominant effects were higher than additive effects in culm length, spike length, awn length, culm diameter, grain length, grain width, number of grains per spike, and 1000 grain weight. The narrow- sense heritability showed high value as 40.06% for spike length.

The Effect on grasp and pinch strength according to degree of elbow flexion in normal adult (성인의 주관절 굴곡 각도가 파악력과 핀치력에 미치는 영향)

  • Lee, Cu-Rie;Kim, Keun-Jo;Kim, Bonn-Won
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.14 no.2
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    • pp.25-33
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    • 2008
  • Purpose : This study was investigated the effect on grasp and pinch strength according to degree of flexion in elbow joint. Methods : Thirty male and thirty female students, aged 20 to 31 years were tested for using opened positioning with their shoulder abduction at $55^{\circ}$ and shoulder horizontal adduction at $30^{\circ}$ in four elbow flexion($0^{\circ}$, $45^{\circ}$, $90^{\circ}$, $135^{\circ}$). An electronic dynamometer(E-LINK V900s Evaluation System)and goniometer were used to measure grasp and pinch strength. Results : The average grasp strength of the dominant hand was strongest at elbow $45^{\circ}$ however, weakest at elbow $135^{\circ}$ flexion in both of male and female. The average pinch strength of the dominant hand was strongest at elbow $135^{\circ}$ flexion in both of male and female. The average pinch strength of dominant hand was weakest at elbow $45^{\circ}$ flexion in both of male and female. According to degree of elbow flexion in both of male and female, grasp and pinch strength was no significant statistically. In analyzing correlations, the grasp strength of male showed the most significant difference at elbow $45^{\circ}$ & $90^{\circ}$ flexion, and the pinch strength was most significant difference at elbow $0^{\circ}$ & $45^{\circ}$ flexion. Conclusion : In analyzing correlations, the grasp strength of female showed the most significant difference at elbow $90^{\circ}$ & $135^{\circ}$ flexion, and the pinch strength was most significant difference at elbow $45^{\circ}$ & $90^{\circ}$ flexion.

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Understanding the Relationship between Value Co-Creation Mechanism and Firm's Performance based on the Service-Dominant Logic (서비스지배논리하에서 가치공동창출 매커니즘과 기업성과간의 관계에 대한 연구)

  • Nam, Ki-Chan;Kim, Yong-Jin;Yim, Myung-Seong;Lee, Nam-Hee;Jo, Ah-Rha
    • Asia pacific journal of information systems
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    • v.19 no.4
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    • pp.177-200
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    • 2009
  • AIn the advanced - economy, the services industry hasbecome a dominant sector. Evidently, the services sector has grown at a much faster rate than any other. For instance, in such developed countries as the U.S., the proportion of the services sector in its GDP is greater than 75%. Even in the developing countries including India and China, the magnitude of the services sector in their GDPs is rapidly growing. The increasing dependence on service gives rise to new initiatives including service science and service-dominant logic. These new initiatives propose a new theoretical prism to promote the better understanding of the changing economic structure. From the new perspectives, service is no longer regarded as a transaction or exchange, but rather co-creation of value through the interaction among service users, providers, and other stakeholders including partners, external environments, and customer communities. The purpose of this study is the following. First, we review previous literature on service, service innovation, and service systems and integrate the studies based on service dominant logic. Second, we categorize the ten propositions of service dominant logic into conceptual propositions and the ones that are directly related to service provision. Conceptual propositions are left out to form the research model. With the selected propositions, we define the research constructs for this study. Third, we develop measurement items for the new service concepts including service provider network, customer network, value co-creation, and convergence of service with product. We then propose a research model to explain the relationship among the factors that affect the value creation mechanism. Finally, we empirically investigate the effects of the factors on firm performance. Through the process of this research study, we want to show the value creation mechanism of service systems in which various participants in service provision interact with related parties in a joint effort to create values. To test the proposed hypotheses, we developed measurement items and distributed survey questionnaires to domestic companies. 500 survey questionnaires were distributed and 180 were returned among which 171 were usable. The results of the empirical test can be summarized as the following. First, service providers' network which is to help offer required services to customers is found to affect customer network, while it does not have a significant effect on value co-creation and product-service convergence. Second, customer network, on the other hand, appears to influence both value co-creation and product-service convergence. Third, value co-creation accomplished through the collaboration of service providers and customers is found to have a significant effect on both product-service convergence and firm performance. Finally, product-service convergence appears to affect firm performance. To interpret the results from the value creation mechanism perspective, service provider network well established to support customer network is found to have significant effect on customer network which in turn facilitates value co-creation in service provision and product-service convergence to lead to greater firm performance. The results have some enlightening implications for practitioners. If companies want to transform themselves into service-centered business enterprises, they have to consider the four factors suggested in this study: service provider network, customer network, value co-creation, and product-service convergence. That is, companies becoming a service-oriented organization need to understand what the four factors are and how the factors interact with one another in their business context. They then may want to devise a better tool to analyze the value creation mechanism and apply the four factors to their own environment. This research study contributes to the literature in following ways. First, this study is one of the very first empirical studies on the service dominant logic as it has categorized the fundamental propositions into conceptual and empirically testable ones and tested the proposed hypotheses against the data collected through the survey method. Most of the propositions are found to work as Vargo and Lusch have suggested. Second, by providing a testable set of relationships among the research variables, this study may provide policy makers and decision makers with some theoretical grounds for their decision making on what to do with service innovation and management. Finally, this study incorporates the concepts of value co-creation through the interaction between customers and service providers into the proposed research model and empirically tests the validity of the concepts. The results of this study will help establish a value creation mechanism in the service-based economy, which can be used to develop and implement new service provision.

Antioxidation Characteristics of Surface-Modified Carbon in ${Al_2}{O_3}$-C Refractory (${Al_2}{O_3}$-C계 내화물에서 표면개질된 탄소의 산화특성)

  • 홍영호;김동한;심광보
    • Journal of the Korean Ceramic Society
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    • v.37 no.6
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    • pp.583-588
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    • 2000
  • Antioxidation characteristics of carbon at high temperature with the co-addition of Al and Si powder in Al2O3-C system refractory were analyzed. The use of surface-modified phosphate carbon as a starting material was found to be very effective in improving the mixing effect of raw materials and antioxidation behavior of carbon. In particular, this effect was dominant at higher temperatures than 130$0^{\circ}C$.

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Flow Patterns of Gas-Liquid Two-phase Flow under Microgravity (미소중력하의 기액이상류의 유동양식)

  • 최부홍
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.3
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    • pp.460-465
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    • 2003
  • Microgravity experiments were conducted to determine the effect of liquid and gas superficial velocities on flow behaviors. Flow behaviors observed under microgravity conditions can be classified into five flow patterns: bubble. Taylor bubble, slug, semi-annular and annular flows. Transition boundary between four flow patterns could be determined by drift-flux model. It was also found that the effect of gravity and pipe inclination on flow pattern transition was not significant in the inertia dominant region.

Effect of Microstructural Factors on Ductility of Drawn Pearlitic Steels (신선가공한 고탄소 강선의 연성에 영향을 주는 미세조직 인자)

  • Nam W. J
    • Transactions of Materials Processing
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    • v.13 no.8
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    • pp.710-715
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    • 2004
  • The effect of microstructural features on ductility of cold drawn pearlitic steels containing 0.52 ~ 0.92 wt%C was investigated. During wire drawing, reduction of area (Rh) increased initially with the progressive realignment of randomly oriented cementite, showed a maximum peak due to the completion of the alignment of most cementite, and decreased with thinning or fragmentation of the aligned cementite. Among factors on ductility, cementite thickness was found to be the most dominant microstructural feature for Rh of drawn pearlitic wires, regardless of transformation temperature and carbon content in steels.

Analysis of Aerosol Optical Properties in Seoul Using Skyradiometer Observation (스카이라디오미터 관측을 통한 서울 상공 에어러솔의 광학적 특성 분석)

  • Koo, Ja-Ho;Kim, Jhoon;Kim, Mi-Jin;Cho, Hi Ku;Aoki, Kazuma;Yamano, Maki
    • Atmosphere
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    • v.17 no.4
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    • pp.407-420
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    • 2007
  • Optical characteristics of aerosols in Seoul are investigated from the measurements of sky radiance by Skyradiometer at Yonsei University from December 2005 to November 2006. Aerosol optical depth (AOD) shows a maximum in June due to weak ventilation and particle growth by aging process and hygroscopic effect. Single scattering albedo (SSA) and Angstrom Exponent (AE) show the lowest value in spring due to the Asian dust. It is clear that coarse mode is dominant in spring and fine mode is dominant in summer from the volume size distribution measured in this study. The explanations on the changes of aerosol loadings are provided through the correlation between AOD and AE, while the pattern of wavelength dependency related to particle size is shown through the correlation between SSA and AE. Backward trajectory analysis by HYSPLIT provides information about origin of aerosol, which allows us to classify the case according to the source region and the path distance. Although the direction of backward trajectory traces back mostly to west, coarse mode particle is dominant in the case of long pathway and fine mode particle is dominant in the case of short pathway. This discrepancy is caused by the regional difference of emitted particles.

Effect of Environmental Factors on Phytoplankton Communities and Dominant Species Succession in Lake Cheongpyeong (환경요인에 따른 청평호 식물플랑크톤 군집 및 우점종의 천이 특성)

  • Youn, Seok Jea;Kim, Hun Nyun;Im, Jong Kwon;Kim, Yong-Jin;Baek, Jun-Soo;Lee, Su-Woong;Lee, Eun Jeong;Yu, Soon Ju
    • Journal of Environmental Science International
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    • v.26 no.8
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    • pp.913-925
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    • 2017
  • Phytoplankton populations were examined at three sites in Lake Cheongpyeong, South Korea from March 2008 to December 2016, including measurement of phytoplankton communities and their dominant species, abundance and environmental factors. The annual average ranges of water temperature, dissolved oxygen and conductivity were $15.2-18.8^{\circ}C$, 10.3-12.2 mg/L, $86-140{\mu}S/cm$, respectively, with similar values at all studied sites. The highest phytoplankton cell density was observed in spring and fall, and it subsequently decreased rapidly during heavy rainfall. Diatoms were dominant in spring (mainly Stephanodiscus hantzschii, Asterionella formosa) and fall (mainly Aulacoseira granulata), while greenalgae and cyanobacteria had high appearance in early-summer and summer, respectively, indicating that water temperature is the most important factor influencing their growth. Stephanodiscus hantzschii and Asterionella formosa frequently occurred at low water temperature ($4.5-15.0^{\circ}C$ and $5.4-21.6^{\circ}C$, respectively) while Aulacoseira granulata and Anabaena spp. were favored by high water temperature (8.6-28.4 and $14.9-26.2^{\circ}C$, respectively) and phosphorus. Additionally, Fragilaria crotonensis occurred at low nutrient conditions. Rhodomonas spp. frequently appeared year-round.