Is prosodic production driven by lexical development ? Longitudinal evidence from babble and words

This study investigated the relation between lexical development and the production of prosodic prominence in disyllabic babble and words. Monthly recordings from nine typically developing Belgian-Dutch-speaking infants were analysed from the onset of babbling until a cumulative vocabulary of 200 words was reached. The differentiation between the two syllables of isolated disyllabic utterances was computed for f0, intensity and duration measurements. Results showed that the ambient trochaic pattern emerged in babble, but became enhanced in words. Words showed more prosodic differentiation in terms of f0 and intensity and a more even duration ratio. Age or vocabulary size did not predict the expansion of f0 or intensity in words, whereas vocabulary size was related to the production of more even-timed syllables. The findings are discussed in terms of lexicalist accounts of phonetic development and a potential phonetic highlighting function of first words

Prosodic modulation in the babble of cochlear implanted and normally hearing infants: a perceptual study using a visual analogue scale

This study investigates prosodic modulation in the spontaneous canonical babble of congenitally deaf infants with cochlear implants (CI) and normally hearing (NH) infants. Research has shown that the acoustic cues to prominence are less modulated in CI babble. However acoustic measurements of individual cues to prominence give incomplete information about prosodic modulation. In the present study, raters are asked to judge prominence since they simultaneously take into account all prosodic cues. Disyllabic utterances produced by CI and NH infants were presented to naive adult raters who had to indicate the degree and direction of prosodic modulation between syllables on a visual analogue scale. The results show that the babble of infants with CI is rated as having less prosodic modulation. Moreover, segmentally more variegated babble is rated as having more prosodic modulation. Raters do not perceive the babble to be predominantly trochaic, which indicates that the predominant stress pattern of Dutch is not yet apparent in the children’s productions

Listeners' perception of lexical stress in the first words of infants with cochlear implants and normally hearing infants

Normally hearing (NH) infants are able to produce lexical stress in their first words, but congenitally hearing-impaired childrenwith cochlear implants (CI) may find this more challenging,given the limited transmission of spectro-temporal information by the implant. Acoustic research has shownthat the acoustic cues to stressin the first words of Dutch-acquiring CI infants are less pronounced (Pettinato et al. 2017). The present study investigate show listeners perceive lexical stress in the first words of CI and NH infants.Two research questions are addressed: (1) How successful are CI and NH children in implementing the prosodic cues to prominence? (2) Is the degree of stress in CI and NHwords perceived to be similar? The stimuli used in this study are disyllabic words (n = 1089) produced by 9 infants with CI and 9 NH infants acquiring Dutch. The words were presented to adult listenersin a listening experiment,in which they assessed the stress pattern on a continuous visual analogue scale (VAS) which expresses to what extent syllables are perceived as stressed.The results show that listeners perceive typical word stress production in the first words of infants with CI. The words of CI and NH infants were rated in agreement with the target stress pattern as often,and trochaic words were rated more frequently as such than iambic words. Listeners more frequently perceive unstressed syllables inthe first words of infants with CI. However, for the words that are perceived to be clearly stressed, the degree of word stress is comparable in the two groups,and both infant groups are perceived to produce more contrast between stressed and unstressed syllables in trochees than in iambs. It is concluded that that acoustic differences between CI and NH infants’ stress production are not necessarily perceptually salient

Space Suit Attachment Quick Release System

NASA plans to make it back to the Moon by 2024 with their Artemis Program, and stay there for a longer period of time to conduct research which will support the future of space exploration. While on the lunar surface, astronauts need to maximize their efficiency by carrying tools on their Exploration Extravehicular Mobility Unit (xEMU), and to accommodate this need, the Extravehicular Activity (EVA) Tools Team is pursuing a utility belt concept. The objective of this project is to develop a system capable of interfacing between the utility belt and any given tool, while also accommodating numerous restrictions and obstacles present on the lunar surface. The design proposed in the Final Design Review Report is a two-piece system made of the tool probe and belt receptacle. The tool probe is made of a wire frame flexure which locks the system in place when docked. The receptacle half is a simple two rung sleeve. This document outlines the final design concept, including the preliminary design process, initial background research, preliminary design concept, design requirements, project timeline, design justification, final design manufacturing procedure, and design verification

Coaxial Jets with Disparate Viscosity: Mixing and Laminarization Characteristics

Mixing of fluids in a coaxial jet is studied under four distinct viscosity ratios, m = 1, 10, 20 and 40, using highly resolved large-eddy simulations (LES), particle image velocimetry and planar laser-induced fluorescence. The accuracy of predictions is tested against data obtained by the simultaneous experimental measurements of velocity and concentration fields. For the highest and lowest viscosity ratios, standard RANS models with unclosed terms pertaining to viscosity variations are employed. We show that the standard Reynolds-averaged Navier-Stokes (RANS) approach with no explicit modelling for variable-viscosity terms is not applicable whereas dynamic LES models provide high-quality agreement with the measurements. To identify the underlying mixing physics and sources of discrepancy in RANS predictions, two distinct mixing modes are defined based on the viscosity ratio. Then, for each mode, the evolution of mixing structures, momentum budget analysis with emphasis on variable-viscosity terms, analysis of the turbulent activity and decay of turbulence are investigated using highly resolved LES data. The mixing dynamics is found to be quite distinct in each mixing mode. Variable viscosity manifests multiple effects that are working against each other. Viscosity gradients induce additional instabilities while increasing overall viscosity decreases the effective Reynolds number leading to laminarization of the turbulent jet, explaining the lack of dispersion and turbulent diffusion. Momentum budget analysis reveals that variable-viscosity terms are significant to be neglected. The scaling of the energy spectrum cascade suggests that in the TLL mode the unsteady laminar shedding is responsible for the eddies observed

SIV Infection Induces Accumulation of Plasmacytoid Dendritic Cells in the Gut Mucosa

Multiple studies suggest that plasmacytoid dendritic cells (pDCs) are depleted and dysfunctional during human immunodeficiency virus/simian immunodeficiency virus (HIV/SIV) infection, but little is known about pDCs in the gut—the primary site of virus replication. Here, we show that during SIV infection, pDCs were reduced 3-fold in the circulation and significantly upregulated the gut-homing marker α4β7, but were increased 4-fold in rectal biopsies of infected compared to naive macaques. These data revise the understanding of pDC immunobiology during SIV infection, indicating that pDCs are not necessarily depleted, but instead may traffic to and accumulate in the gut mucosa

Search for supersolidity in 4He in low-frequency sound experiments

We present results of the search for supersolid 4He using low-frequency, low-level mechanical excitation of a solid sample grown and cooled at fixed volume. We have observed low frequency non-linear resonances that constitute anomalous features. These features, which appear below about 0.8 K, are absent in 3He. The frequency, the amplitude at which the nonlinearity sets in, and the upper temperature limit of existence of these resonances depend markedly on the sample history.Comment: Submitted to the Quantum Fluids and Solids Conf. Aug. 2006 Kyot

SIV Infection Induces Accumulation of Plasmacytoid Dendritic Cells in the Gut Mucosa

Multiple studies suggest that plasmacytoid dendritic cells (pDCs) are depleted and dysfunctional during human immunodeficiency virus/simian immunodeficiency virus (HIV/SIV) infection, but little is known about pDCs in the gut—the primary site of virus replication. Here, we show that during SIV infection, pDCs were reduced 3-fold in the circulation and significantly upregulated the gut-homing marker α4β7, but were increased 4-fold in rectal biopsies of infected compared to naive macaques. These data revise the understanding of pDC immunobiology during SIV infection, indicating that pDCs are not necessarily depleted, but instead may traffic to and accumulate in the gut mucosa