1,366 research outputs found
Can Copyright Lend Its Cinderellaic Magic To Chinese Folklore?, 5 J. Marshall Rev. Intell. Prop. L. 203 (2006)
Folklore in China is disappearing and facing challenges for its very survival. To salvage folklore in China, some have called for immediate legislative action and proposed the law of copyright or sui generis protection as some potential solutions. However, copyright is traditionally concerned with the creations of individuals rather than the cumulative creations of an ethnic group or region. Furthermore, even sui generis protection, which is better adapted to folklore in theory, could be susceptible in practice to the abuses of private monopolies or state tyranny. Overall, the protection of folklore depends more on a consistent governmental policy of open-mindedness toward its use and dissemination than on any piece of legislation
A new Late Devonian genus with seed plant affinities
Background: Many ovules of Late Devonian (Famennian) seed plants have been well studied. However, because few taxa occur with anatomically preserved stems and/or petioles, the vascular system of these earliest spermatophytes is little understood and available data come mostly from Euramerica. There remains great controversy over the anatomical differentiation of Late Devonian and Carboniferous seed plant groups of Buteoxylonales, Calamopityales and Lyginopteridales. Protostele evolution of these early spermatophytes needs more research. Results: A new taxon Yiduxylon trilobum gen. et sp. nov. with seed plant affinities has been discovered in the Upper Devonian (Famennian) Tizikou Formation of Hubei Province, China. It is represented by stems, helically arranged and bifurcate fronds with two orders of pinnae and planate pinnules. Both secondary pinnae and pinnules are borne alternately. Stems contain a small protostele with three primary xylem ribs possessing a single peripheral protoxylem strand. Thick secondary xylem displays multiseriate bordered pitting on the tangential and radial walls of the tracheids, and has biseriate to multiseriate and high rays. A narrow cortex consists of inner cortex without sclerotic nests and sparganum-type outer cortex with peripheral bands of vertically aligned sclerenchyma cells. Two leaf traces successively arise tangentially from each primary xylem rib and they divide once to produce four circular-oval traces in the stem cortex. Four vascular bundles occur in two C-shaped groups at each petiole base with ground tissue and peripheral bands of sclerenchyma cells. Conclusions: Yiduxylon justifies the assignment to a new genus mainly because of the protostele with protoxylem strands only near the periphery of primary xylem ribs, leaf trace origination and petiolar vascular supply structure. It shares many definitive characters with Calamopityales and Lyginopteridales, further underscoring the anatomical similarities among early seed plants. The primary vascular system, pycnoxylic-manoxylic secondary xylem with bordered pits on both tangential and radial walls of a tracheid and leaf trace divergence of Yiduxylon suggest transitional features between the early spermatophytes and ancestral aneurophyte progymnosperms.Evolutionary BiologyGenetics & HereditySCI(E)[email protected]
Hadwiger’s conjecture for powers of cycles and their complements
AbstractC. Thomassen showed that powers of certain cycles are counterexamples to Hajós’ conjecture. We prove that powers of cycles and their complements satisfy Hadwiger’s conjecture, that is, every k-chromatic graph has a k-clique as a minor
Computer Simulation of Three Particles Sedimentation in a Narrow Channel
The settling of three particles in a narrow channel is simulated via the lattice Boltzmann direct-forcing/fictitious domain (LB-DF/FD) method for the Reynolds number ranging from 5 to 200. The effects of the wall and the Reynolds number are studied. It is interesting to find that at certain Reynolds numbers the left (right) particle is settling at 0.175 (0.825) of the channel width irrespective of its initial position or the channel width. Moreover, numerical results have shown that the lateral particles lead at small Reynolds numbers, while the central particle leads at large Reynolds numbers due to the combined effects of particle-particle and particle-wall interactions. The central particle will leave the lateral ones behind when the Reynolds number is large enough. Finally the effect of the Reynolds number on the trajectory of the lateral particles is presented
ISOKINETIC PEAK TORQUE OF CONCENTRIC AND ECCENTRIC CONTRACTION
The purpose of this study was to examine the isokinetic peak torque of plantar flexion and dorsiflexion in male and female. Seventy college students volunteered to participate in this study. Cybex-6000 dynamometer was employed in this study to examined the isokinetic concentric (CON) and eccentric (ECC) strength of ankle plantar flexion and dorsiflexion at 60, 120, 180, 240, and 300/s. Peak torques (PT) and peak torques relative to body mass for ankle plantar flexion and dorsiflexion were studied. The results indicated that ECC PT was greater than CON PT and plantar flexion PT was greater than dorsiflexion PT in both females and males. The ECC PT did not increase with increasing angular velocity. This study also showed that it was more reasonable to normalize PT relative to body mass when comparing the differences of strength between males and females
Gene silencing in mammalian cells by PCR-based short hairpin RNA
AbstractRNA interference (RNAi) provides a powerful tool to silence genes in a sequence-specific manner in a variety of systems. However, not all sequences are effective in the RNAi-mediated gene silencing. In this study, we developed a polymerase chain reaction (PCR)-based RNAi strategy for a quick screening of small interfering RNA (siRNA) efficiency. This method utilized a two-step PCR to generate a chimeric DNA template containing the U6 promoter or cytomegalovirus promoter and short hairpin DNA. We demonstrated that the transfection of the PCR products into mammalian cells resulted in specific depressions of exogenous (luciferase, green fluorescent protein and β-galactosidase) and endogenous (annexin II) gene expressions. This PCR strategy provides a rapid, easy and cheap approach for testing candidates siRNA sequences and is an attractive alternative to subcloning
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