61 research outputs found

    Effect of formant frequency spacing on perceived gender in pre-pubertal children's voices

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    <div><p>Background</p><p>It is usually possible to identify the sex of a pre-pubertal child from their voice, despite the absence of sex differences in fundamental frequency at these ages. While it has been suggested that the overall spacing between formants (formant frequency spacing - ΔF) is a key component of the expression and perception of sex in children's voices, the effect of its continuous variation on sex and gender attribution has not yet been investigated.</p><p>Methodology/Principal findings</p><p>In the present study we manipulated voice ΔF of eight year olds (two boys and two girls) along continua covering the observed variation of this parameter in pre-pubertal voices, and assessed the effect of this variation on adult ratings of speakers' sex and gender in two separate experiments. In the first experiment (sex identification) adults were asked to categorise the voice as either male or female. The resulting identification function exhibited a gradual slope from male to female voice categories. In the second experiment (gender rating), adults rated the voices on a continuum from “masculine boy” to “feminine girl”, gradually decreasing their masculinity ratings as ΔF increased.</p><p>Conclusions/Significance</p><p>These results indicate that the role of ΔF in voice gender perception, which has been reported in adult voices, extends to pre-pubertal children's voices: variation in ΔF not only affects the perceived sex, but also the perceived masculinity or femininity of the speaker. We discuss the implications of these observations for the expression and perception of gender in children's voices given the absence of anatomical dimorphism in overall vocal tract length before puberty.</p></div

    Wavelet transform selection method for biological signal treatment

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    This paper presents the development and evaluation of an algorithm for compressing fetal electrocardiographic signals, taken superïŹcially on the mother’s abdomen. This method for acquiring ECG signals produces a great volumen of information that makes it diïŹƒcult for the records to be stored and transmitted. The proposed algorithm aims for lossless compression of the signal by applying Wavelet Packet Transform to keep errors below the unit, with compression rates over 20:1 and with conserved energy in reconstruction as comparison parameter. For algorithm validation, the signal ïŹles provided by PhysioBank DataBase are used

    Sex differences in the Simon task help to interpret sex differences in selective attention.

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    In the last decade, a number of studies have reported sex differences in selective attention, but a unified explanation for these effects is still missing. This study aims to better understand these differences and put them in an evolutionary psychological context. 418 adult participants performed a computer-based Simon task, in which they responded to the direction of a left or right pointing arrow appearing left or right from a fixation point. Women were more strongly influenced by task-irrelevant spatial information than men (i.e., the Simon effect was larger in women, Cohen's d = 0.39). Further, the analysis of sex differences in behavioral adjustment to errors revealed that women slow down more than men following mistakes (d = 0.53). Based on the combined results of previous studies and the current data, it is proposed that sex differences in selective attention are caused by underlying sex differences in core abilities, such as spatial or verbal cognition

    Spontaneous Voice Gender Imitation Abilities in Adult Speakers

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    Background The frequency components of the human voice play a major role in signalling the gender of the speaker. A voice imitation study was conducted to investigate individuals' ability to make behavioural adjustments to fundamental frequency (F0), and formants (Fi) in order to manipulate their expression of voice gender. Methodology/Principal Findings Thirty-two native British-English adult speakers were asked to read out loud different types of text (words, sentence, passage) using their normal voice and then while sounding as ‘masculine’ and ‘feminine’ as possible. Overall, the results show that both men and women raised their F0 and Fi when feminising their voice, and lowered their F0 and Fi when masculinising their voice. Conclusions/Significance These observations suggest that adult speakers are capable of spontaneous glottal and vocal tract length adjustments to express masculinity and femininity in their voice. These results point to a “gender code”, where speakers make a conventionalized use of the existing sex dimorphism to vary the expression of their gender and gender-related attributes

    Physics-Based Earthquake Ground Shaking Scenarios in Large Urban Areas

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    With the ongoing progress of computing power made available not only by large supercomputer facilities but also by relatively common workstations and desktops, physics-based source-to-site 3D numerical simulations of seismic ground motion will likely become the leading and most reliable tool to construct ground shaking scenarios from future earthquakes. This paper aims at providing an overview of recent progress on this subject, by taking advantage of the experience gained during a recent research contract between Politecnico di Milano, Italy, and Munich RE, Germany, with the objective to construct ground shaking scenarios from hypothetical earthquakes in large urban areas worldwide. Within this contract, the SPEED computer code was developed, based on a spectral element formulation enhanced by the Discontinuous Galerkin approach to treat non-conforming meshes. After illustrating the SPEED code, different case studies are overviewed, while the construction of shaking scenarios in the Po river Plain, Italy, is considered in more detail. Referring, in fact, to this case study, the comparison with strong motion records allows one to derive some interesting considerations on the pros and on the present limitations of such approach

    Evidence of a chimpanzee-sized ancestor of humans but a gibbon-sized ancestor of apes

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    Body mass directly affects how an animal relates to its environment and has a wide range of biological implications. However, little is known about the mass of the last common ancestor (LCA) of humans and chimpanzees, hominids (great apes and humans), or hominoids (all apes and humans), which is needed to evaluate numerous paleobiological hypotheses at and prior to the root of our lineage. Here we use phylogenetic comparative methods and data from primates including humans, fossil hominins, and a wide sample of fossil primates including Miocene apes from Africa, Europe, and Asia to test alternative hypotheses of body mass evolution. Our results suggest, contrary to previous suggestions, that the LCA of all hominoids lived in an environment that favored a gibbon-like size, but a series of selective regime shifts, possibly due to resource availability, led to a decrease and then increase in body mass in early hominins from a chimpanzee-sized LCA

    Four-Dimensional Consciousness

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    Probing Conformational Change of Intrinsically Disordered alpha-Synuclein to Helical Structures by Distinctive Regional Interactions with Lipid Membranes

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    alpha-Synuclein (alpha-Syn) is an intrinsically disordered protein, whose fibrillar aggregates are associated with the pathogenesis of Parkinson&apos;s disease. alpha-Syn associates with lipid membranes and forms helical structures upon membrane binding. In this study, we explored the helix formation of alpha-Syn in solution containing trifluoroethanol using small-angle X-ray scattering and electrospray ionization ion mobility mass spectrometry. We then investigated the structural transitions of alpha-Syn to helical structures via association with large unilamellar vesicles as model lipid membrane systems. Hydrogen deuterium exchange combined with electrospray ionization mass spectrometry was further utilized to understand the details of the regional interaction mechanisms of alpha-Syn with lipid vesicles based on the polarity of the lipid head groups. The characteristics of the helical structures were observed with alpha-Syn by adsorption onto the anionic phospholipid vesicles via electrostatic interactions between the N-terminal region of the protein and the anionic head groups of the lipids. alpha-Syn also associates with zwitterionic lipid vesicles and forms helical structures via hydrophobic interactions. These experimental observations provide an improved understanding of the distinct structural change mechanisms of alpha-Syn that originate from different regional interactions of the protein with lipid membranes and subsequently provide implications regarding diverse protein-membrane interactions related to their fibrillation kinetics.X111615sciescopu
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