217 research outputs found
Divergence and Shannon information in genomes
Shannon information (SI) and its special case, divergence, are defined for a
DNA sequence in terms of probabilities of chemical words in the sequence and
are computed for a set of complete genomes highly diverse in length and
composition. We find the following: SI (but not divergence) is inversely
proportional to sequence length for a random sequence but is length-independent
for genomes; the genomic SI is always greater and, for shorter words and longer
sequences, hundreds to thousands times greater than the SI in a random sequence
whose length and composition match those of the genome; genomic SIs appear to
have word-length dependent universal values. The universality is inferred to be
an evolution footprint of a universal mode for genome growth.Comment: 4 pages, 3 tables, 2 figure
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Musicians show enhanced perception, but not production, of native lexical tones
Many studies have reported a musical advantage in perceiving lexical tones among non-native listeners, but it is unclear whether this advantage also applies to native listeners, who are likely to show ceiling-like performance and thus mask any potential musical advantage. The ongoing tone merging phenomenon in Hong Kong Cantonese provides a unique opportunity to investigate this as merging tone pairs are reported to be difficult to differentiate even among native listeners. In the present study, native Cantonese musicians and non-musicians were compared on their discrimination and identification of merging Cantonese tone pairs to determine whether a musical advantage in their perception will be observed, and if so, whether this is seen on the phonetic and/or phonological level. The tonal space of their lexical tone production was also compared. Results indicated that the musicians outperformed the non-musicians on the two perceptual tasks, as indexed by their higher accuracy and faster reaction time, particularly on the most difficult tone pair. In the production task, however, there was no group difference in various indices of their tonal space. Taken together, musical experience appears to facilitate native listeners’ perception, but not production, of lexical tones, which partially supports a music-to-language transfer effect
4-(2-Methoxyphenyl)piperazin-1-ium 6-chloro-5-isopropyl-2,4-dioxopyrimidin-1-ide
In the cation of the title salt, C11H17N2O+.C7H8ClN2O2
-, the piperazine ring adopts a distorted chair conformation and contains a positively charged N atom with quaternary character. Its mean plane makes a dihedral angle of 42.36 (8)� with the phenyl ring of its 2-methoxyphenyl
substituent. The 2,4-dioxopyrimidin-1-ide anion is generated by deprotonation of the N atom at the 1-position of the pyrimidinedione ring. Intramolecular C—H...O hydrogen bonds generate S(6) ring motifs in both the cation and the anion. In the crystal, N—H...O, N—H...N and C—H...O hydrogen bonds are also observed, resulting in a twodimensional network parallel to the ab plane. The crystal stability is further consolidated by weak C—H...n interactions
3-(Adamantan-1-yl)-4-benzyl-1H-1,2,4-triazole-5(4H)-thione
The title compound, C19H23N3S, is a functionalized triazoline-3-thione derivative. The benzyl ring is almost normal to the planar 1,2,4-triazole ring (r.m.s. deviation = 0.007 A°) with a dihedral angle of 86.90 (7)°. In the crystal, molecules are linked by pairs of N—H...S hydrogen bonds, forming inversion dimers that enclose R2/2(8) loops. The crystal packing is further stabilized by weak C—H...n interactions that link adjacent dimeric units into supramolecular chains extending along the a-axis direction
A Development Framework for Rapid Metaheuristics Hybridization
While meta-heuristics are effective for solving large-scale combinatorial optimization problems, they result from time-consuming trial-and-error algorithm design tailored to specific problems. For this reason, a software tool for rapid prototyping of algorithms would save considerable resources. This paper presents a generic software framework that reduces development time through abstract classes and software reuse, and more importantly, aids design with support of user-defined strategies and hybridization of meta-heuristics. Most interestingly, we propose a novel way of redefining hybridization with the use of the “request and response ” metaphor, which form an abstract concept for hybridization. Different hybridization schemes can now be formed with minimal coding, which gives our proposed Metaheuristics Development Framework its uniqueness. To illustrate the concept, we restrict to two popular metaheuristics Ants Colony Optimization and Tabu Search, and demonstrate MDF through the implementation of various hybridized models to solve the Traveling Salesman Problem. 1
Bis[benzyl N′-(3-phenylprop-2-enylidene)hydrazinecarbodithioato-κ2 N′,S]zinc(II)
In the title ZnII complex, [Zn(C17H15N2S2)2], the ZnII atom lies on a twofold rotation axis. It exists in a tetrahedral geometry, chelated by two deprotonated Schiff base ligands. The dihedral angle between each ligand is 71.48 (8)°. Molecules are connected by weak C—H⋯S intermolecular interactions into chains along the c axis. The crystal structure is further stabilized by C—H⋯π interactions involving the phenyl ring of the 3-phenylprop-2-enylidene unit
Heroes and villains of world history across cultures
© 2015 Hanke et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedEmergent properties of global political culture were examined using data from the World History Survey (WHS) involving 6,902 university students in 37 countries evaluating 40 figures from world history. Multidimensional scaling and factor analysis techniques found only limited forms of universality in evaluations across Western, Catholic/Orthodox, Muslim, and Asian country clusters. The highest consensus across cultures involved scientific innovators, with Einstein having the most positive evaluation overall. Peaceful humanitarians like Mother Theresa and Gandhi followed. There was much less cross-cultural consistency in the evaluation of negative figures, led by Hitler, Osama bin Laden, and Saddam Hussein. After more traditional empirical methods (e.g., factor analysis) failed to identify meaningful cross-cultural patterns, Latent Profile Analysis (LPA) was used to identify four global representational profiles: Secular and Religious Idealists were overwhelmingly prevalent in Christian countries, and Political Realists were common in Muslim and Asian countries. We discuss possible consequences and interpretations of these different representational profiles.This research was supported by grant RG016-P-10 from the Chiang Ching-Kuo Foundation for International Scholarly Exchange (http://www.cckf.org.tw/).
Religion
Culture
Entropy
China
Democracy
Economic histor
Crystal structure of 3-[(4-benzylpiperazin-1-yl)methyl]-5-(thiophen-2-yl)- 2,3-dihydro-1,3,4-oxadiazole-2-thione
The title 1,3,4-oxadiazole-2-thione derivative, C18H20N4OS2,
crystallized with two independent molecules (A and B) in the
asymmetric unit. The 2-thienyl rings in both molecules are
rotationally disordered over two orientations by approximately
180� about the single C—C bond that connects it to the
oxadiazole thione ring; the ratios of site occupancies for the
major and minor components were fixed in the structure
refinement at 0.8:0.2 and 0.9:0.1 in molecules A and B,
respectively. The 1,3,4-oxadiazole-2-thione ring forms dihedral
angles of 7.71 (16), 10.0 (11) and 77.50 (12)� (molecule
A), and 6.5 (3), 6.0 (9) and 55.30 (12)� (molecule B) with the
major and minor parts of the disordered thiophene ring and
the mean plane of the adjacent piperazine ring, respectively,
resulting in approximately V-shaped conformations for the
molecules. The piperazine ring in both molecules adopts a
chair conformation. The terminal benzene ring is inclined
towards the mean plane of the piperazine ring with N—C—
C—C torsion angles of �58.2 (3) and �66.2 (3)� in molecules
A and B, respectively. In the crystal, no intermolecular
hydrogen bonds are observed. The crystal packing features
short S� � �S contacts [3.4792 (9) A ° ] and �–� interactions
[3.661 (3), 3.664 (11) and 3.5727 (10) A ° ], producing a threedimensional
network
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