1,232 research outputs found

    Masking release due to linguistic and phonetic dissimilarity between the target and masker speech

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    Purpose: To investigate masking release for speech maskers for linguistically and phonetically close (English and Dutch) and distant (English and Mandarin) language pairs. Method: Thirty-two monolingual speakers of English with normal audiometric thresholds participated in the study. Data are reported for an English sentence recognition task in English and for Dutch and Mandarin competing speech maskers (Experiment 1) and noise maskers (Experiment 2) that were matched either to the long-term average speech spectra or to the temporal modulations of the speech maskers from Experiment 1. Results: Listener performance increased as the target-tomasker linguistic distance increased (English-in-English < English-in-Dutch < English-in-Mandarin). Conclusion: Spectral differences between maskers can account for some, but not all, of the variation in performance between maskers; however, temporal differences did not seem to play a significant role

    Estimating Density Dependence, Environmental Variance, and Long-Term Selection on a Stage-Structured Life History

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    A method for analyzing long-term demographic data on density-dependent stage-structured populations in a stochastic environment is derived to facilitate comparison of populations and species with different life histories. We assume that a weighted sum of stage abundances, N, exerts density dependence on stage-specific vital rates of survival and reproduction and that N has a small or moderate coefficient of variation. The dynamics of N are approximated as a univariate stochastic process governed by three key parameters: the density-independent growth rate, the net density dependence, and environmental variance in the life history. We show how to estimate the relative weighs of stages in N and the key parameters. Life history evolution represents a stochastic maximization of a simple function of the key parameters. The long-term selection gradient on the life history can be expressed as a vector of sensitivities of this function with respect to density-independent, density-dependent, and stochastic components of the vital rates. To illustrate the method, we analyze 38 years of demographic data on a great tit population, estimating the key parameters, which accurately predict the observed mean, coefficient of variation, and fluctuation rate of N; we also evaluate the long-term selection gradient on the life history.</p

    Universal Continuous Variable Quantum Computation in the Micromaser

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    We present universal continuous variable quantum computation (CVQC) in the micromaser. With a brief history as motivation we present the background theory and define universal CVQC. We then show how to generate a set of operations in the micromaser which can be used to achieve universal CVQC. It then follows that the micromaser is a potential architecture for CVQC but our proof is easily adaptable to other potential physical systems.Comment: 12 pages, 4 figures, accepted for a presentation at the 9th International Conference on Unconventional Computation (UC10) and LNCS proceedings

    Upper-mantle cross-section from California to Greenland

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    Pure-path upper-mantle models appropriate for tectonic, shield and old ocean have been recently presented by Grand and Helmberger. This was accomplished by modeling a rather restricted data set of S and SS triplication waveforms as well as the beginning portion of the Love waves. A much larger data set of S, SS and SSS, etc. (multibounce S-wave triplications) with a mixture of tectonic paths is available. In particular, events usually occur at tectonic margins and are recorded on stable continents. We present results of modeling these observations for laterally varying structure, essentially along a profile from California to Greenland. The models are allowed to be locally dipping with the lithosphere thickening with age at the expense of a dwindling low-velocity zone. Lateral variation does not appear to be required for depths greater than 400 km along this particular profile. The best-fitting model has a large increase in lithospheric thickness near the Rocky Mountain Front, roughly an increase of 75 km in thickness over a horizontal distance of 400 km or less. The low-velocity zone, with a velocity of 4.4 km/s, is replaced by a much faster upper 300 km with velocities near 4.7 km/s or a 7% overall increase. The one-way travel time jumps by roughly 4 s across this boundary, which compares reasonably well with the direct S residuals obtained from deep earthquake data although the latter data show large scatter. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ARK: https://n2t.net/ark:/88439/y069500 Permalink: https://geophysicsjournal.com/article/12 &nbsp

    Give me a break! Unavoidable fatigue effects in cognitive pupillometry

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    Issue Online: 08 June 2023Pupillometry has a rich history in the study of perception and cognition. One perennial challenge is that the magnitude of the task-evoked pupil response diminishes over the course of an experiment, a phenomenon we refer to as a fatigue effect. Reducing fatigue effects may improve sensitivity to task effects and reduce the likelihood of confounds due to systematic physiological changes over time. In this paper, we investigated the degree to which fatigue effects could be ameliorated by experimenter intervention. In Experiment 1, we assigned participants to one of three groups—no breaks, kinetic breaks (playing with toys, but no social interaction), or chatting with a research assistant—and compared the pupil response across conditions. In Experiment 2, we additionally tested the effect of researcher observation. Only breaks including social interaction significantly reduced the fatigue of the pupil response across trials. However, in all conditions we found robust evidence for fatigue effects: that is, regardless of protocol, the task-evoked pupil response was substantially diminished (at least 60%) over the duration of the experiment. We account for the variance of fatigue effects in our pupillometry data using multiple common statistical modeling approaches (e.g., linear mixed-effects models of peak, mean, and baseline pupil diameters, as well as growth curve models of time-course data). We conclude that pupil attenuation is a predictable phenomenon that should be accommodated in our experimental designs and statistical models.Agencia Estatal de Investigación, Grant/Award Number: CEX2020-001010- S; Eusko Jaurlaritza; National Institutes of Health, Grant/ Award Number: R01 DC014281 and R01 DC019507; National Science Foundation, Grant/Award Number: DGE-174503

    Modelling radiation-induced cell cycle delays

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    Ionizing radiation is known to delay the cell cycle progression. In particular after particle exposure significant delays have been observed and it has been shown that the extent of delay affects the expression of damage such as chromosome aberrations. Thus, to predict how cells respond to ionizing radiation and to derive reliable estimates of radiation risks, information about radiation-induced cell cycle perturbations is required. In the present study we describe and apply a method for retrieval of information about the time-course of all cell cycle phases from experimental data on the mitotic index only. We study the progression of mammalian cells through the cell cycle after exposure. The analysis reveals a prolonged block of damaged cells in the G2 phase. Furthermore, by performing an error analysis on simulated data valuable information for the design of experimental studies has been obtained. The analysis showed that the number of cells analyzed in an experimental sample should be at least 100 to obtain a relative error less than 20%.Comment: 19 pages, 11 figures, accepted for publication in Radiation and Environmental Biophysic
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