137 research outputs found
The Role of Native Language and the Fundamental Design of the Auditory System in Detecting Rhythm Changes
Accepted December 13, 2018Purpose: We investigated whether rhythm discrimination
is mainly driven by the native language of the listener or
by the fundamental design of the human auditory system
and universal cognitive mechanisms shared by all people
irrespective of rhythmic patterns in their native language.
Method: In multiple experiments, we asked participants to
listen to 2 continuous acoustic sequences and to determine
whether their rhythms were the same or different (AX
discrimination). Participants were native speakers of
4 languages with different rhythmic properties (Spanish,
French, English, and German) to understand whether the
predominant rhythmic patterns of a native language affect
sensitivity, bias, and reaction time in detecting rhythmic
changes in linguistic (Experiment 2) and in nonlinguistic
(Experiments 1 and 2) acoustic sequences. We examined
sensitivity and bias measures, as well as reaction times.
We also computed Bayes factors in order to assess the
effect of native language.
Results: All listeners performed better (i.e., responded
faster and manifested higher sensitivity and accuracy)
when detecting the presence or absence of a rhythm
change when the 1st stimulus in an AX test pair exhibited
regular rhythm (i.e., a syllable-timed rhythmic pattern)
than when the 1st stimulus exhibited irregular rhythm (i.e.,
stress-timed rhythmic pattern). This result pattern was
observed both on linguistic and nonlinguistic stimuli
and was not modulated by the native language of the
participant.
Conclusion: We conclude that rhythm change detection is
a fundamental function of a processing system that relies
on general auditory mechanisms and is not modulated by
linguistic experience.The authors acknowledge support from Spanish Ministry of Economy and Competitiveness Grant PSI2017-82563-P (awarded to A. G. S.), the “Severo Ochoa” Programme for Centres/Units of Excellence in R&D Grant SEV-2015-490 (BCBL), and the Basque Foundation for Science Grant IKERBASQUE (awarded to A. G. S. and M. O.). D. M. G. was supported by Grant PIA/Basal FB0003 from the Chilean Research Council. L. P. was supported by the Spanish Ministry of Economy and Competitiveness via Juan de la Cierva fellowship
Analytical and numerical analyses of the micromechanics of soft fibrous connective tissues
State of the art research and treatment of biological tissues require
accurate and efficient methods for describing their mechanical properties.
Indeed, micromechanics motivated approaches provide a systematic method for
elevating relevant data from the microscopic level to the macroscopic one. In
this work the mechanical responses of hyperelastic tissues with one and two
families of collagen fibers are analyzed by application of a new variational
estimate accounting for their histology and the behaviors of their
constituents. The resulting, close form expressions, are used to determine the
overall response of the wall of a healthy human coronary artery. To demonstrate
the accuracy of the proposed method these predictions are compared with
corresponding 3-D finite element simulations of a periodic unit cell of the
tissue with two families of fibers. Throughout, the analytical predictions for
the highly nonlinear and anisotropic tissue are in agreement with the numerical
simulations
Mapping between long-time molecular and Brownian dynamics
We use computer simulations to test a simple idea for mapping between
long-time self diffusivities obtained from molecular and Brownian dynamics. The
strategy we explore is motivated by the behavior of fluids comprising particles
that interact via inverse-power-law pair potentials, which serve as good
reference models for dense atomic or colloidal materials. Based on our
simulation data, we present an empirical expression that semi-quantitatively
describes the "atomic" to "colloidal" diffusivity mapping for inverse-power-law
fluids, but also for model complex fluids with considerably softer
(star-polymer, Gaussian-core, or Hertzian) interactions. As we show, the
anomalous structural and dynamic properties of these latter ultrasoft systems
pose problems for other strategies designed to relate Newtonian and Brownian
dynamics of hard-sphere-like particles.Comment: 12 pages, 5 figure
Global Ocean Sediment Composition and Burial Flux in the Deep Sea
Quantitative knowledge about the burial of sedimentary components at the seafloor has wide-ranging implications in ocean science, from global climate to continental weathering. The use of 230Th-normalized fluxes reduces uncertainties that many prior studies faced by accounting for the effects of sediment redistribution by bottom currents and minimizing the impact of age model uncertainty. Here we employ a recently compiled global data set of 230Th-normalized fluxes with an updated database of seafloor surface sediment composition to derive atlases of the deep-sea burial flux of calcium carbonate, biogenic opal, total organic carbon (TOC), nonbiogenic material, iron, mercury, and excess barium (Baxs). The spatial patterns of major component burial are mainly consistent with prior work, but the new quantitative estimates allow evaluations of deep-sea budgets. Our integrated deep-sea burial fluxes are 136 Tg C/yr CaCO3, 153 Tg Si/yr opal, 20Tg C/yr TOC, 220 Mg Hg/yr, and 2.6 Tg Baxs/yr. This opal flux is roughly a factor of 2 increase over previous estimates, with important implications for the global Si cycle. Sedimentary Fe fluxes reflect a mixture of sources including lithogenic material, hydrothermal inputs and authigenic phases. The fluxes of some commonly used paleo-productivity proxies (TOC, biogenic opal, and Baxs) are not well-correlated geographically with satellite-based productivity estimates. Our new compilation of sedimentary fluxes provides detailed regional and global information, which will help refine the understanding of sediment preservation
Globally invariant metabolism but density-diversity mismatch in springtails.
Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning
Chiral Separation of Underivatized Amino Acids by Reactive Extraction with Palladium−BINAP Complexes
Learning from Poverty: Why Business Schools Should Address Poverty, and How They Can Go About It.
In the past few years, business schools have begun to address poverty issues in their teaching, learning and curricula. While this is a positive development, the arguments for reconfiguring educational programs to address such matters remain undeveloped, with much of the impetus for such endeavors rooted in calls for social responsibility in the United Nations Millennium Development Goals, the Social Compact, the Principles for Responsible Management Education and benchmarks such as ISO 26000. This article seeks to clarify the pedagogical grounds for integrating poverty issues in management education by examining the intellectual and personal development benefits of doing so. By critically examining four modes of business involvement in poverty reduction, the article shows how such initiatives can be used as intellectual lenses through which to view the complex and often paradoxical interconnections between socioeconomic and environmental systems. It is thus concluded that a consideration of poverty issues is not a marginal matter, but is key to grasping the 21st century complexities of global business and management
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