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• An acoustic-to-kinematic model to project acoustic dynamics to jaw-tongue kinematics has been proposed. • A weight estimation method based on gradient-descent has been used in reducing estimation errors. • A weight optimization method based on signal realignment has been defined. • Time delays from male and female Parkinson's Disease patients have been estimated. • Large and small movement ranges in hypokinetic dysarthria have been obtained from acoustic signals. Speech signal analysis is a powerful tool that facilitates the monitoring and tracking of symptom deterioration caused by neurodegenerative disorders, typically achieved using either sustained vowels, diadochokinetic exercises or running speech. This study expands our previous work on the study of the movement produced by the jaw-tongue biomechanical system. The aim is to further investigate the effects of neuromotor activity during muscular exertion that translates formant acoustics into speech articulatory movements affected by hypokinetic dysarthria in Parkinson's Disease (PD). The objective of this study is to estimate the parameters of an inverse acoustic-to-kinematic projection model that takes as an input the variations of the first and second formants and estimates as output the spatial variation of the jaw-tongue biomechanical system. The spatial variations have been extracted from 3D accelerometry (3DAcc). These serve as ground truth for comparison with the estimated activity projected from speech kinematics, as a measure of fitness of the inverse model. The estimation method is a two step process: first initial weight values are produced using multiple regression between each of the formant dynamic signals (acoustical analysis) and the estimated spatial variations (accelerometry). The second step uses a weight refinement method based on gradient-descent. Additionally, a time-realignment study has been carried out on the acoustic-to-kinematic projection model, based on the estimation of relative time displacements as to maximize the cross-correlation between signals. The study is complemented with an estimation of the model weights on a dataset from PD participants and Healthy Controls (HC). This methodology opens up new ways to investigate the underlying physiological voice production mechanism which may offer new insights into PD symptoms. [ABSTRACT FROM AUTHOR]

• Biomechanical description of phonation in Down syndrome (DS) from acoustical correlates. • Classical acoustic analysis is not sharp enough to observe phenomena underlying neurological dysfunctions in DS. • Distortions may be linked to neuromotor alterations in DS. • Tremor is larger in Down syndrome group (DSG) compared to Normative group (NG). • Laryngeal tremor may be related with neuromotor dysfunctions of DS. Down Syndrome (DS) has been the aim of numerous studies, although its phonation specificities have not received much attention. DS is a genetic disorder caused by the presence of a third copy of chromosome 21, being the explanation of different behavioral and clinical anomalies: developmental disorders, hearing, speech and language impairments and neuromotor and morphological alterations of the oro-naso-pharyngeal (ONP) and laryngeal (ONL) structures. The goal of the current study is to carry on a first approach to the biomechanics of phonation in DS children from an acoustic perspective, trying to describe its specificities and to establish a link with the syndrome. A specific application designed to analyze the glottal source and its relationship to vocal fold biomechanics has been used. Nineteen biomechanical features from vocal fold dynamics have been used, related to fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, mass and stiffness profiles, unbalance, contact gaps, and tremor. On one hand, the non-normophonic corpus is composed of eight children with DS with age range between five and six years old. On the other hand, a normative or normophonic population was taken. The last group consisted of eight children with similar ages to the previous ones. The results achieved show relevant differences (p <.05) in larynx biomechanics regarding the following features: deviations in the fundamental frequency, vocal fold tension (regarding musculus vocalis), and phonation tremor. These distortions could be directly related with the neuromotor alterations known to be associated to DS and could reflect underlying factors of DS phonation features. [ABSTRACT FROM AUTHOR]

Coronavirus stands for a large family of viruses characterized by protruding spikes surrounding a lipidic membrane adorned with proteins. The present study explores the adhesion of transmissible gastroenteritis coronavirus (TGEV) particles on a variety of reference solid surfaces that emulate typical virus-surface interactions. Atomic force microscopy informs about trapping effectivity and the shape of the virus envelope on each surface, revealing that the deformation of TGEV particles spans from 20% to 50% in diameter. Given this large deformation range, experimental Langmuir isotherms convey an unexpectedly moderate variation in the adsorption-free energy, indicating a viral adhesion adaptability which goes beyond the membrane. The combination of an extended Helfrich theory and coarse-grained simulations reveals that, in fact, the envelope and the spikes present complementary adsorption affinities. While strong membrane-surface interaction lead to highly deformed TGEV particles, surfaces with strong spike attraction yield smaller deformations with similar or even larger adsorption-free energies., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)