467 research outputs found

    Anisotropic fluids in the case of stationary and axisymmetric spaces of General Relativity

    Get PDF
    We present a stationary axisymmetric solution belonging to Carter's family [A] of spaces and representing an anisotropic fluid configuration.Comment: 14 pages,submitted to Int J Mod Phys

    Harmonic organisation conveys both universal and culture-specific cues for emotional expression in music

    Get PDF
    Previous research conducted on the cross-cultural perception of music and its emotional content has established that emotions can be communicated across cultures at least on a rudimentary level. Here, we report a cross-cultural study with participants originating from two tribes in northwest Pakistan (Khow and Kalash) and the United Kingdom, with both groups being naïve to the music of the other respective culture. We explored how participants assessed emotional connotations of various Western and non-Western harmonisation styles, and whether cultural familiarity with a harmonic idiom such as major and minor mode would consistently relate to emotion communication. The results indicate that Western concepts of harmony are not relevant for participants unexposed to Western music when other emotional cues (tempo, pitch height, articulation, timbre) are kept relatively constant. At the same time, harmonic style alone has the ability to colour the emotional expression in music if it taps the appropriate cultural connotations. The preference for one harmonisation style over another, including the major-happy/minor-sad distinction, is influenced by culture. Finally, our findings suggest that although differences emerge across different harmonisation styles, acoustic roughness influences the expression of emotion in similar ways across cultures; preference for consonance however seems to be dependent on cultural familiarity

    The Wahlquist-Newman solution

    Get PDF
    Based on a geometrical property which holds both for the Kerr metric and for the Wahlquist metric we argue that the Kerr metric is a vacuum subcase of the Wahlquist perfect-fluid solution. The Kerr-Newman metric is a physically preferred charged generalization of the Kerr metric. We discuss which geometric property makes this metric so special and claim that a charged generalization of the Wahlquist metric satisfying a similar property should exist. This is the Wahlquist-Newman metric, which we present explicitly in this paper. This family of metrics has eight essential parameters and contains the Kerr-Newman-de Sitter and the Wahlquist metrics, as well as the whole Pleba\'nski limit of the rotating C-metric, as particular cases. We describe the basic geometric properties of the Wahlquist-Newman metric, including the electromagnetic field and its sources, the static limit of the family and the extension of the spacetime across the horizon.Comment: LaTeX, 18 pages, no figures. Accepted for publication in Phys. Rev.

    Modularity Facilitates Flexible Tuning of Plastic and Evolutionary Gene Expression Responses during Early Divergence

    Get PDF
    Gene expression changes have been recognized as important drivers of adaptation to changing environmental conditions. Little is known about the relative roles of plastic and evolutionary responses in complex gene expression networks during the early stages of divergence. Large gene expression data sets coupled with in silico methods for identifying coexpressed modules now enable systems genetics approaches also in nonmodel species for better understanding of gene expression responses during early divergence. Here, we combined gene coexpression analyses with population genetics to separate plastic and population (evolutionary) effects in expression networks using small salmonid populations as a model system. We show that plastic and population effects were highly variable among the six identified modules and that the plastic effects explained larger proportion of the total eigengene expression than population effects. A more detailed analysis of the population effects using a Q(ST)-F-ST comparison across 16,622 annotated transcripts revealed that gene expression followed neutral expectations within modules and at the global level. Furthermore, two modules showed enrichment for genes coding for early developmental traits that have been previously identified as important phenotypic traits in thermal responses in the same model system indicating that coexpression analysis can capture expression patterns underlying ecologically important traits. We suggest that module-specific responses may facilitate the flexible tuning of expression levels to local thermal conditions. Overall, our study indicates that plasticity and neutral evolution are the main drivers of gene expression variance in the early stages of thermal adaptation in this system

    A hybrid framework for nonlinear dynamic simulations including full-field optical measurements and image decomposition algorithms

    Get PDF
    Innovative designs of transport vehicles need to be validated in order to demonstrate reliability and provide confidence. It is normal practice to study the mechanical response of the structural elements by comparing numerical results obtained from finite element simulation models with results obtained from experiment. In this frame, the use of wholefield optical techniques has been proven successful in the validation of deformation, strain, or vibration modes. The strength of full-field optical techniques is that the entire displacement field can be acquired. The objective of this article is to integrate full-field optical measurement methodologies with state-of-the-art computational simulation techniques for nonlinear transient dynamic events. In this frame, composite car bonnet frame structures of dimensions about 1.8 m 30.8 m are considered. They have been tested in low-velocity mass-drop impact loading with impact energies ranging from 20 to 200 J. In parallel, simulation models of the car bonnet frame have been developed using layered shell elements. The Zernike shape descriptor approach was used to decompose numerical and experimental data into moments for comparison purposes. A very good agreement between numerical and experimental results was observed. Therefore, integration of numerical analysis with full-field optical measurements along with sophisticated comparison techniques can increase design reliability

    Harmonic organisation conveys both universal and culture-specific cues for emotional expression in music

    Get PDF
    Previous research conducted on the cross-cultural perception of music and its emotional content has established that emotions can be communicated across cultures at least on a rudimentary level. Here, we report a cross-cultural study with participants originating from two tribes in northwest Pakistan (Khow and Kalash) and the United Kingdom, with both groups being naïve to the music of the other respective culture. We explored how participants assessed emotional connotations of various Western and non-Western harmonisation styles, and whether cultural familiarity with a harmonic idiom such as major and minor mode would consistently relate to emotion communication. The results indicate that Western concepts of harmony are not relevant for participants unexposed to Western music when other emotional cues (tempo, pitch height, articulation, timbre) are kept relatively constant. At the same time, harmonic style alone has the ability to colour the emotional expression in music if it taps the appropriate cultural connotations. The preference for one harmonisation style over another, including the major-happy/minor-sad distinction, is influenced by culture. Finally, our findings suggest that although differences emerge across different harmonisation styles, acoustic roughness influences the expression of emotion in similar ways across cultures; preference for consonance however seems to be dependent on cultural familiarity
    corecore