• Title/Summary/Keyword: Cross Structure

Search Result 2,451, Processing Time 0.029 seconds

Spermatogenesis and Ultrastructural Characteristics of Spermatozoa of Brackish Water Diploid Clam, Corbicula japonica (Bivalvia: Corbiculidae) (기수산 2배체 재첩, Corbicula japonica(Bivalvia: Corbiculidae)의 정자형성과정 및 정자의 미세구조적 특징)

  • Jun, Je-Cheon;Kim, Bong-Seok;Chung, Ee-Yung;Kim, Jin-Hee;Park, Gab-Man;Park, Sung-Woo
    • Development and Reproduction
    • /
    • v.13 no.2
    • /
    • pp.115-122
    • /
    • 2009
  • Spermatogenesis and ultrastructural characteristics of sperm of brackish water diploid Corbicula japonica were investigated by electron microscope observations. Based on the cytological studies, the spermatozoon of this species (brackish water diploid) C japonica is approximately 55 ${\mu}m$ in length. The sperm head (about 12 ${\mu}m$ long) is elongated and tapers with a slight curve. Sperm nucleus is about 7.90 ${\mu}m$ long, and the acrosome is about 2.70 ${\mu}m$ long: The morphologies of the sperm nucleus type and the acrosome shape of this species are a long arrow-like type and long cone-like shape, respectively. The sperm head of this species (external fertilization, dioecious and oviparous species) is partially modified from that of the primitive type, as seen in triploid Corbicula species (internal fertilization, hermaphrodite and ovoviparous species), reported by some authors. However, this species produces uniflagellate spermatozoa, unlike freshwater triploid hermaphroditic clams being possessed of partially modified biflagellate spermatozoa. Diploid C japonica is similar to those of other bivalves being possessed of a short midpiece containing four mitochondria surrounding the centrioles. The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure, and from uniflagellate sperm cross sectioned, in particular, wing-like axonernal lateral fins are observed, as seen in external fertilization fishes.

  • PDF

Development and Application of Enzyme Immunoassay for Endosulfan Residue Analysis (Endosulfan 과 그 분해산물의 Enzyme Immunoassay에 의한 분석법의 개발과 응용)

  • Suh, Yong-Tack;Shim, Jae-Han;Lee, Kang-Bong
    • Korean Journal of Environmental Agriculture
    • /
    • v.11 no.1
    • /
    • pp.59-66
    • /
    • 1992
  • An enzyme immunoassay(EIA) was developed for the analysis of insecticide endosulfan and its degradation products. The sensitivity and specificity of the antibody produced were examined. Optimal conditions in the ELISA system for residue analysis were also discussed. A mixed suspension of endosulfan-hemocyanin conjugate(ES-KLH) 1.1 mg/ml and Freund's adjuvant was injected subcutaneously to white rabbits and then collected antisera were tested for titers by indirect ELISA(1/24,000). Because of difficulties in the synthesis of endosulfan peroxidase conjugate, amine derivative of endosulfan-diol was synthesized and it showed 40% of conjugate yields(2mg/ml of conjugate). the highest sensitivity obtained enzyme-conjugate was a concentration of 200ng/ml. The detection limit of endosulfan in ELISA system was 5 ppb on the standard curve. In application of ELISA for residue analysis, the recoveries were really 100% both in the spiked soil and apple sample regardless of endosulfan concentration treated. On the other hand, chlorinated hydrocarbons of similar structure with endosulfan showed low cross-reactivity$(2.2%{\sim}29.2%).$

  • PDF

Physiological Responses and Fruit Quality Changes of 'Fuji' Apple under the High Night Temperature (야간 고온에 의한 사과 후지 품종의 생리반응 및 과실품질 변화)

  • Ryu, Suhyun;Kwon, YongHee;Do, Kyeong Ran;Han, Jeom Hwa;Han, Hyun Hee;Lee, Han Chan
    • Journal of Bio-Environment Control
    • /
    • v.24 no.3
    • /
    • pp.264-270
    • /
    • 2015
  • Tropical night phenomenon has been increasing due to global warming recently, it is expected that fruit quality of apples will decrease due to elevated night temperature condition. In the present study, fruit quality at maturity, periodic anthocyanin biosynthetic gene expression and sugar contents in leaves and fruit flesh were investigated to establish the physiological responses of 'Fuji' apples under high night temperature. The night temperature were treated with such as ambient (control), ambient $-4^{\circ}C$, and ambient $+4^{\circ}C$. After the treatment, high night temperature didn't affect fruit diameter, weight, and soluble sugar contents. Coloration of ambient $+4^{\circ}C$ was poor than that of control, however there was no significant difference between these genes expression of control and that of ambient $+4^{\circ}C$ treatment in the late coloration season. Increase of sorbitol and glucose contents at ambient $+4^{\circ}C$ in leaves were smaller than those at control, and then sorbitol and sucrose contents in fruit flesh at ambient $+4^{\circ}C$ were smaller than those at control. The cross section of leaves showed that there were no differences with the structure of parenchyma and epidermis tissues between the treatments, but starch granules in the palisade parenchyma cells decreased in high night temperature treatments. Consequently, high night temperature didn't affect the fruit quality, but changed sugar contents in leaves and fruit flesh, and suppressed coloration regardless of anthocyanin biosynthetic gene expression.

The Effects of Management Consulting Quality and Consultant Capability on Entrepreneurial Firms' Performance (창업기업의 경영성과에 있어서 컨설팅품질과 컨설턴트역량의 영향에 대한 연구: 흡수능력과 자원역량의 매개효과를 중심으로)

  • Yoon, Ki-Chang
    • Journal of Distribution Science
    • /
    • v.14 no.5
    • /
    • pp.81-89
    • /
    • 2016
  • Purpose - Prior researches have empirically focused on the effect of management consulting quality and consultant capability on entrepreneurial firms' performance. This study, however, focused on investigating the moderating role of absorptive capacity and resource capability between management consulting and entrepreneurial firms' performance. So, this study investigated the relationship among consulting quality, consultant capability, absorptive capacity, resource capability, and entrepreneurial firms' performance from the resource based view (RBV). Especially, this study focused on the mediating role of absorptive and resource capability in relational structure of entrepreneurial firms' dimensions. Research design, data, and methodology - In this study, research hypotheses and model are established by the prior researches from the fields of strategic management and entrepreneurial behavior. Concretely, H1~H4 are the relationship between consulting (consulting quality, consultant capability) and innovation (absorptive capacity, resource capability); H5 is the relationship between absorptive capacity and resource capability; and H6~H7 are the relationship between innovation (absorptive capacity, resource capability) and management performance. The data was collected 207 copies from entrepreneurial firms in South Korea. These firms were established in January 2014 and maintained by November 2015 in high-tech industry. The questionnaire was consisted of five dimensions; consulting quality, consultant capability, absorptive capacity, resource capability, and management performance. Each dimension measured multi items on a 5-point Likert scale. The hypotheses and research model are analyzed using structural equation modeling (SEM) with AMOS 22. Results - The results of this study are as follows. 1) Consulting quality significantly influenced on the absorptive capacity of entrepreneurial firms. 2) But, consultant capability did not influence on the absorptive capacity of entrepreneurial firms. 3) Consulting quality and consultant capability significantly influenced on the resource capability of entrepreneurial firms. 4) Absorptive capacity significantly influenced on the resource capability of entrepreneurial firms; 5) Absorptive capacity did not significantly influence on the management performance of entrepreneurial firms. 6) Resource capability, however, significantly influenced on the management performance of entrepreneurial firms. By these results, absorptive capacity of entrepreneurial firms had a mediating role partly among consulting quality, consultant capability, and management capability. The resource capability of entrepreneurial firms had a mediating role among consulting quality, consultant capability, and management capability, perfectly. Conclusions - According to this study, the high level of consulting quality and consultant capability may enforce the resource capability of entrepreneurial firms. It means, practically, that external knowledge is a driver for innovation, and then the innovation effects on the management performance of entrepreneurial firms. So, at the initial stage, the management consulting programs are very important to entrepreneurial firms and should be conceived as an essential element. This study may contribute to the advancement of academic in field of new start business, small business, or venture business based on resources, especially the role of absorptive capacity and resource capability between consulting programs and management performance. However, this study has some limitations. They are the measurement of consulting quality's items, cross-sectional research, and the limitation of concept and industry.

Modification of a Smoking Motivation Questionnaire for Chinese Medical Students

  • Jiang, Chao;Sun, Wen-Jie;Wan, Yan-Chun;Wei, Ming-Wei;Mu, Yong-Ping;Tarver, Siobhan L.;Gao, Yong-Qing;Hu, Tian;Xu, Chao;Gordon, James;Feng, Cindy Xin;Wen, Yu-Feng
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.6
    • /
    • pp.2707-2711
    • /
    • 2014
  • Introduction: Smoking prevalence among the medical students is high in China. Therefore, understanding the smoking motivations of medical students is crucial for smoking control, but currently there are no scales questionnaires customized for probing the smoking motivations of medical students. This aim of study was to test and modify a questionnaire for investigating smoking motivations among medical students. Methods: A cross-sectional survey was conducted among 1,125 medical students at Xuzhou Medical College in China in 2012.The model fit and validity was assessed by confirmatory factor analysis (CFA) and the reliability was tested by single-item reliability, composite reliability, and item-total correlation. Results: The prevalence of smoking was 9.84 % among study population. In the modified scales, the global fit indices identified a CFI value of 0.96, TLI was 0.96, and the RMSEA was 0.063. CFA supported the two dimensional structure of the instrument. The average variance extracted ranged from 0.45 to 0.62. All single-item reliability scores were greater than 0.20, and the composite reliability ranged from 0.74 to 0.91. Conclusion: Modified scales could be the preliminary instrument used in evaluating the smoking motivations of medical students. However, it should be further assessed using other forms and methods of validity and reliability, additional motivations of smoking, and the survey of other medical colleges in China.

The narrative features of as seen through digital culture (<이제부터 제리타임 It's Jerry Time!>을 통해 본 디지털 문화 속 웹 애니메이션의 서사적 특징)

  • Kim, YoungOk
    • Cartoon and Animation Studies
    • /
    • s.34
    • /
    • pp.23-43
    • /
    • 2014
  • The development of the Internet in the 21st century had made a variety of cross-cultural environment so that animations also have evolved with new features to Web-Animation. In Korea, the web-based flash animation leap forward to the animation Utopia in the early 2000's, but did not last long. The web-based animations should attract audience's attention not only with it's minimum streaming capacity but also with showing it's best qualities as well, Therefore, the stimulating narrative strategies were mandatories for web-animation in 2000's. The absence of in-depth research on media, poor revenue structure, and the emergence of mobile games and e-learning industries made the web-animation become just a one-time/one-consumable content. There were no subsequent generation of korean web-animation ever since. In this study, I want to introduce and analyze the american web animation series, (2005) as a new type of web-animation in current digital culture, In particular, I want to discuss how this web animation appeal to the audience with its narrative strategies through using some aspect of the internet culture which's differentiated from traditional media based cultures. This research could suggest diverse narrative strategies for the future web-animation with new vision. Moreover, This also allows to look at latest web-animation trends and its new experiments.

KorLexClas 1.5: A Lexical Semantic Network for Korean Numeral Classifiers (한국어 수분류사 어휘의미망 KorLexClas 1.5)

  • Hwang, Soon-Hee;Kwon, Hyuk-Chul;Yoon, Ae-Sun
    • Journal of KIISE:Software and Applications
    • /
    • v.37 no.1
    • /
    • pp.60-73
    • /
    • 2010
  • This paper aims to describe KorLexClas 1.5 which provides us with a very large list of Korean numeral classifiers, and with the co-occurring noun categories that select each numeral classifier. Differently from KorLex of other POS, of which the structure depends largely on their reference model (Princeton WordNet), KorLexClas 1.0 and its extended version 1.5 adopt a direct building method. They demand a considerable time and expert knowledge to establish the hierarchies of numeral classifiers and the relationships between lexical items. For the efficiency of construction as well as the reliability of KorLexClas 1.5, we use following processes: (1) to use various language resources while their cross-checking for the selection of classifier candidates; (2) to extend the list of numeral classifiers by using a shallow parsing techniques; (3) to set up the hierarchies of the numeral classifiers based on the previous linguistic studies; and (4) to determine LUB(Least Upper Bound) of the numeral classifiers in KorLexNoun 1.5. The last process provides the open list of the co-occurring nouns for KorLexClas 1.5 with the extensibility. KorLexClas 1.5 is expected to be used in a variety of NLP applications, including MT.

The Econometric Evaluation of the Impact of R&D Incentive on Technological Outcomes (R&D지원정책이 기술성과에 미치는 영향분석)

  • Lee, Johng-Ihl;Kim, Chan-Jun
    • Journal of Korea Technology Innovation Society
    • /
    • v.10 no.1
    • /
    • pp.1-21
    • /
    • 2007
  • Among numerous policy influencers' and researchers' advices and policy suggestions, there is little opposition to the proposition that technology is essential to the economic development. The role of technology has never been more emphasized than today in Korea as in any other countries. The effects of the government's innovation policy on corporate R&D activities and more broadly the economic welfare of a whole nation are widely recognized with intuitional and empirical evidence. That is, various R&D incentives reduce the marginal cost of a firm's R&D efforts, inducing as much increase of its R&D investment to result in a better chance to acquire target technology. This paper examines the impact of R&D incentives on the technological outcomes by analyzing individual firms' investment behaviors subject to the government's R&D incentive policies. An econometric model of technological outcomes is estimated on a project level with cross-sectional data. "Probit model" is employed for estimations. Special attention was given to the effectiveness of R&D programs by estimating policy impact by types of investment. The data were collected from 928 different R&D projects completed between 1987 and 1993. With the single equation approach, we were able to find that the structure of investment is a far more significant factor in technological outcomes than the total amount of investment. The analysis also shows that the two types of firms' matching investment, in-kind and cash, do not bear a complementary, but a substitutive relations to each other. It also reconfirms the proposition that R&D incentives increase firm's financial investment. Despite many supportive studies emphasizing the cooperation between innovation performers, it is also found that the larger the number of institutions involved in a project, the less likely it leads to a technological success, And meeting the proposed deadlines without postponing is estimated to be a good barometer to predict the outcome of an R&D project. Also the probabilities of success for major variables are represented for policy implications, after calculating marginal effects.

  • PDF

Preparation and Characterization of Removal-type Acrylic Pressure-Sensitive Adhesive (4원 아크릴계 박리형 점착제의 제조와 특성에 관한 연구)

  • Seo, Young-Ok;Seul, Soo-Duk
    • Elastomers and Composites
    • /
    • v.36 no.4
    • /
    • pp.225-236
    • /
    • 2001
  • In order to improve the properties of the copolymer and the terpolymer that was used as removal-type pressure sensitive adhesive(PSA), we synthesized quaterpolymer with the variation of the types of monomer, initiator, and solvent, and concentration, the monomer/solvent ratio, reaction temperature and time. and determined the properties of this adhesive: the viscosity, molecular weight, conversion, solid content and structure of polymer. The prepared polymer was crosslinked by changing the type of crosslinking agent and concentration, and then we investigated the characteristics or adhesive such as peel adhesion, shear adhesion, heat resistance, weathering resistance and peel adhesion to aging. The optimum performance of RA/2- EHA/MMA/2-HEMA as a PSA were obtained when benzoyl peroxide was used as an initiator with the reactant mixture consisted of 80% BA and 2-EHA, 15%, MMA, and 5% 2-HFMA. The optimum reaction temperature and time were $80^{\circ}C$ and 8 hours, respectively. For BA/2-EHA/MMA/AA, the optimum performance was obtained when the polymerization was performed at the monomer composition of 80% BA/2-EHA, 15% MMA, and 5% AA. BPO was used as initiator and the optimum reaction temperature and time were identical to those of BA/2-EHA/MMA/ 2-HEMA. Isocyanate and melamine were used to crosslink BA/2-EHA/MMA/2-HEMA and BA/2-EHA/MMA/AA, respectively. No effect on the type of cross-linking agent on the peel adhesion was observed with aging. The quarterpolymers crosslinked with melamine left residues on the counter surface after weathering resistance test, while the polymers crosslinked with isocyanate did not.

  • PDF

Analysis on the Driving Safety and Investment Effect using Severity Model of Fatal Traffic Accidents (대형교통사고 심각도 모형에 의한 주행안전성 및 투자효과 분석)

  • Lim, Chang-Sik;Choi, Yang-Won
    • Journal of Korean Society of Transportation
    • /
    • v.29 no.3
    • /
    • pp.103-114
    • /
    • 2011
  • In this study, we discuss a fatal accident severity model obtained from the analysis of 112 crash sites collected since 2000, and the resulting relationship between fatal accidents and roadway geometry design. From the 720 times computer simulations for improving driving safety, we then reached the following conclusions:. First, the result of cross and frequency-analyses on the car accident sites showed that 43.7% of the accidents occurred on the curved roads, 60.7% on the vertical curve section, 57.2% on the roadways with radius of curvature of 0 to 24m, 83.9% on the roads with superelevation of 0.1 to 2.0% and 49.1% on the one-way 2-lane roads; vehicle types involved are passenger vehicles (33.0%), trucks (20.5%) and buses (14.3%) in order of frequency. The results also show that the superelevation is the most influencing factor for the fatal accidents. Second, employing the Ordered Probit Model (OPM), we developed a severity model for fatal accidents being a function of on various road conditions so as to the damages can be predicted. The proposed model possibly assists the practitioners to predict dangerous roadway segments, and to take appropriate measures in advance. Third, computer simulation runs show that providing adequate superelevation on the segment where a fatal accident occurred could reduce similar fatal accidents by at least 85%. This result indicates that the regulations specified in the Rule for Road Structure and Facility Standard (description and guidelines) should be enhanced to include more specific requirement for providing the superelevation.