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Search Results: 1 - 10 of 57302 matches for " Wen-kai Jiang "
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Evolution of MicroRNA Genes in Oryza sativa and Arabidopsis thaliana: An Update of the Inverted Duplication Model
Yun Zhang, Wen-kai Jiang, Li-zhi Gao
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0028073
Abstract: The origin and evolution of microRNA (miRNA) genes, which are of significance in tuning and buffering gene expressions in a number of critical cellular processes, have long attracted evolutionary biologists. However, genome-wide perspectives on their origins, potential mechanisms of their de novo generation and subsequent evolution remain largely unsolved in flowering plants. Here, genome-wide analyses of Oryza sativa and Arabidopsis thaliana revealed apparently divergent patterns of miRNA gene origins. A large proportion of miRNA genes in O. sativa were TE-related and MITE-related miRNAs in particular, whereas the fraction of these miRNA genes much decreased in A. thaliana. Our results show that the majority of TE-related and pseudogene-related miRNA genes have originated through inverted duplication instead of segmental or tandem duplication events. Based on the presented findings, we hypothesize and illustrate the four likely molecular mechanisms to de novo generate novel miRNA genes from TEs and pseudogenes. Our rice genome analysis demonstrates that non-MITEs and MITEs mediated inverted duplications have played different roles in de novo generating miRNA genes. It is confirmed that the previously proposed inverted duplication model may give explanations for non-MITEs mediated duplication events. However, many other miRNA genes, known from the earlier proposed model, were rather arisen from MITE transpositions into target genes to yield binding sites. We further investigated evolutionary processes spawned from de novo generated to maturely-formed miRNA genes and their regulatory systems. We found that miRNAs increase the tunability of some gene regulatory systems with low gene copy numbers. The results also suggest that gene balance effects may have largely contributed to the evolution of miRNA regulatory systems.
An experimental study on distribution of musk into the brain through blood brain barrier
CHEN Wen-Kai
Zhong Xi Yi Jie He Xue Bao , 2004,
Abstract: Objective: To study the possible pathway of the effect of musk on brain disorder,distributing into the brain through blood brain barrier. Methods: We used the musk ketone (muscone), a main composition of musk,to inject through the tail vein of the rats into the blood and took the brain and other organs at different times to make samples. Then gas chromatography was used to measure the distribution of muscone in the brain and other organs.Results: Muscone could pass through the normal rat's blood brain barrier into the brain and soon reached the highest peak and remained in higher concentration, and more slowly metabolized as compared with other organs.Conclusion: Musk distributing into the brain through blood brain barrier provides the basis for its effect in treating brain disorders. Chromatography is an effective method to study the active composition of Chinese herbal medicine distributing through the blood brain barrier into the brain.
Birefringence Caused by the Presence of Permanent Dipoles and Its Possible Threat on the Accuracy of Traditional Surface Plasmon  [PDF]
Po-Yu Tsai, Chien-Jung Liao, Wen-Kai Kuo, Chungpin Liao
World Journal of Condensed Matter Physics (WJCMP) , 2011, DOI: 10.4236/wjcmp.2011.11002
Abstract: In arriving at the more intuitive “scattering form” of the Fresnel equations, microscopic physical electric and magnetic dipoles were rigorously employed as the source of electromagnetic waves by Doyle et al. Motivated by such an ap-proach, the authors started to speculate how the incorporation of permanent dipoles might affect Brewster angle of a specific optical material. It is found that in the presence of permanent dipoles, not only is the Brewster angle dependent on the incident light power as well as the dipole orientation, but also that two conjugate incident light paths result in distinctively different refractions. Experiments on dipole-engineered polyvinylidene fluoride films show that by way of adding/reducing permanent dipole density and varying orientations, the aforementioned theoretical predictions can be evidenced unambiguously in the visible light range. Further, effective polarization density can be quantified from the above experiments subjected to different dipole engineering processes. As a result, the traditionally elliptic contour of a slanted two dimensional section of the refractive index ellipsoid now manifests symmetric open splittings at near the traditional incident angle. It implies that severe challenge to the accuracy of traditional surface plasmon resonance measurements may arise in the presence of permanent dipoles of various morphologies, such as in the forms of na-no-particles or membrane double layers.
A Comparative Analysis of the Value of Information in a Continuous Time Market Model with Partial Information: The Cases of Log-Utility and CRRA
Zhaojun Yang,Christian-Oliver Ewald,Wen-Kai Wang
Journal of Probability and Statistics , 2011, DOI: 10.1155/2011/238623
Abstract: We study the question what value an agent in a generalized Black-Scholes model with partial information attributes to the complementary information. To do this, we study the utility maximization problems from terminal wealth for the two cases partial information and full information. We assume that the drift term of the risky asset is a dynamic process of general linear type and that the two levels of observation correspond to whether this drift term is observable or not. Applying methods from stochastic filtering theory we derive an analytical tractable formula for the value of information in the case of logarithmic utility. For the case of constant relative risk aversion (CRRA) we derive a semianalytical formula, which uses as an input the numerical solution of a system of ODEs. For both cases we present a comparative analysis. 1. Introduction The economics of information and more precisely the way how information influences our strategic opportunities is a topic which is more and more discussed among economists, with applications in basically all behavioral sciences but particularly in finance. To an increase in strategic opportunities corresponds an increase in the level of maximal obtainable utility. This increase can be associated with a financial value and it is this value what is usually referred to as the value of information. This value depends in general on the whole model, assets, strategies, agents preferences, and so forth, and technically the same information can have different values for different agents and different underlying models. For more background on the general foundations of information economics we refer to Birchler and Büttler [1] and Hirshleifer and Riley [2]. In the specific context of stock markets the aspect of additional information and its value has been studied by various authors; see, for example, Amendinger et al. [3], Imkeller [4], Ewald [5], and Kohatsu-Higa and Sulem [6] as only to mention a view. While the first three focus on the case of initially enlarged filtration in the sense of Jacod [7], Kohatsu-Higa provides a rather general framework, which appears however to be to technical as to obtain analytical or numerical expressions for the value of information. All of the four models mentioned above treat the case of a representative agent, which either does or does not have an increased level of information, but there is no interaction between differently informed agents and no active exchange of information from one agent to another. The aspect of agent interaction and its strategic consequences in the
KEY CHARACTERISTICS AND DISTRIBUTION OF XIUYU TILE CLAY RESOURCES IN THE COASTAL REGION OF FUJIAN PROVINCE
福建省秀屿磁砖粘土资源主要特性与分布研究

ZHANG Wen-kai,
张文开

资源科学 , 2003,
Abstract: Based on the landform analysis, investigation and sampling in the field, three distributional areas of tile clay in Hushi Peninsula in the coastal region of Fujian Province have been defined. The key characteristics of Xiuyu clay have been researched through the sintering and chemical analysis of the clay samples. It indicates that the tile clay located under the soil is distributed over the low-lying land of the platform in Hushi Peninsula. By the quality analysis, the Xiuyu tile clay can be used as tile original material. This research indicates that Hushi Peninsula will be rich in tile clay resources, which is expected to compensate the shortage of tile clay resources in Fujian Province. As this paper discusses the characteristics and spatial distribution pattern of tile clay resources in the coastal region of Fujian Province, it will be provide reference for tile clay resources utilization within this region.
Determinants of User Intention toward IT Instruction: an Examination of Internal and External Factors
Show-Hui S. Huang,Wen-Kai K. Hsu
Knowledge Management & E-Learning : an International Journal , 2009,
Abstract: This paper discusses the internal and external factors that affect user intention to apply IT instruction. The internal factors were examined from the standpoint of user attitudes toward IT instruction, which included computer knowledge, perceived usefulness, and interest in applying IT instruction, while external factors included climate, school policy, facility, and training in IT instruction. The effects of participant demographics were also investigated. As an empirical study, 141 valid science and technology university teachers in Taiwan were surveyed for their experiences with teaching websites. The results indicate that all of the internal factors significantly affect teacher intention to apply IT instruction, but none of the external factors do, except for the climate variable. The results may help school administrators in promoting IT instruction.
Effects of ginsenoside Rg1 on expression of insulin-like growth factor-1 in brain of rats with brain contusion
Wen-kai LI,Fei-jun HUANG
Zhong Xi Yi Jie He Xue Bao , 2008,
Abstract: Objective: To study the effects of ginsenoside Rg1 on the expression of insulin-like growth factor-1 (IGF-1) in the brain of rats after the experimental brain contusion.Methods: A total of twenty-six Wistar rats were randomly divided into normal control group (n=2), untreated group (n=8) and ginsenoside Rg1 group (n=16). Brain injuries were induced in rats by a mechanical striking device. The brain tissues were extracted at different times after brain injury (6th hour, 12th hour, 2nd day, 6th day), then the expression of IGF-1 in brain tissue was examined by immunohistochemical method.Results: In comparison with the normal control group, the expression of IGF-1 in the brain tissues was increased in the untreated group after the brain contusion (P<0.05). The expression of IGF-1 in brain tissues in ginsenoside Rg1 group was significantly increased as compared with the untreated group (P<0.05).Conclusion: Ginsenoside Rg1 enhances the recovery of the contused brain through increasing the expression of IGF-1.
Transition Texture Synthesis
Yueh-Yi Lai,Wen-Kai Tai,
Yueh-Yi
,Lai,and,Wen-Kai,Tai

计算机科学技术学报 , 2008,
Abstract: Synthesis of transition textures is essential for displaying visually acceptable appearances on a terrain.This investigation presents a modified method for synthesizing the transition texture to be tiled on a terrain.All transition pattern types are recognized for a number of input textures.The proposed modified patch-based sampling texture synthesis approach,using the extra feature map of the input source and target textures for patch matching,can synthesize any transition texture on a succession pattern by initializing the output texture using a portion of the source texture enclosed in a transition cut.The transition boundary is further enhanced to improve the visual effect by tracing out the integral texture elements.Either the Game of Life model or Wang tiles method are exploited to present a good-looking profile of successions on a terrain for tiling transition textures.Experimental results indicate that the proposed method requires few input textures,yet synthesizes numerous tileable transition textures,which are useful for obtaining a vivid appearance of a terrain.
Dispersion analysis of a coupled-cavity slow wave structure filled with plasma
等离子体加载耦合腔慢波结构色散分析

Wang Bin,Xie Wen-Kai,
王彬
,谢文楷

物理学报 , 2007,
Abstract: Utilizing the method of longitudinal field and the dielectric tensor of the magnetized plasma, the accurate expressions for the field in the plasma drifting channel were derived. Under given boundary conditions and using the moments method, the dispersion relations were obtained. The dispersion characteristics in low-density and high-density loaded plasmas were studied. The plasma space-charge wave and the formation of the hybrid modes were discussed.
Orthogonal polynomial spectrum subtraction for multiple attenuation
压制多次波的正交多项式谱减法

XUE Ya-Ru,CHEN Xiao-Hong,LU Wen-Kai,
薛亚茹

地球物理学报 , 2009,
Abstract: Based on orthogonal polynomial spectrum subtraction, a new multiple suppression method is proposed. In the orthogonal polynomial spectrum of seismic data, the high order coefficients mainly present the multiple. By using the relationship between the low order and the high order coefficients, the low order coefficients of multiple can be derived from high order ones. By subtracting from the orthogonal polynomial spectrum of the seismic data, multiple orthogonal polynomial spectrums are removed from the seismic data. The method can separate primaries and multiples especially in near offset, which are overlapping in orthogonal polynomial spectrum, and the AVO properties are also preserved. The processing of synthetic data shows good results.
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