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1. Variation in compensatory strategies as a function of target constriction degree in post-glossectomy speech

   https://doi.org/10.1121/10.0009897  

   Hagedorn, Christina; Lu, Yijing; Toutios, Asterios; Sinha, Uttam; Goldstein, Louis; Narayanan, Shrikanth (April 2022, JASA Express Letters)

   Individuals who have undergone treatment for oral cancer oftentimes exhibit compensatory behavior in consonant production. This pilot study investigates whether compensatory mechanisms utilized in the production of speech sounds with a given target constriction location vary systematically depending on target manner of articulation. The data reveal that compensatory strategies used to produce target alveolar segments vary systematically as a function of target manner of articulation in subtle yet meaningful ways. When target constriction degree at a particular constriction location cannot be preserved, individuals may leverage their ability to finely modulate constriction degree at multiple constriction locations along the vocal tract. 

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2. Significance of Vocal Tract Geometrical Variations and Loudness on Airflow and Droplet Dispersion in a Two-Dimensional Representation of [F]

   https://doi.org/10.1115/FEDSM2021-65485  

   Mofakham, Amir A.; Helenbrook, Brian T.; Ahmed, Tanvir; Erath, Byron D.; Ferro, Andrea R.; Brown, Deborah M.; Ahmadi, Goodarz (October 2021, The American Society of Mechanical Engineers Fluids Engineering Division Summer Meeting)

   Abstract The significance of respiratory droplet transmission in spreading respiratory diseases such as COVID-19 has been identified by researchers. Although one cough or sneeze generates a large number of respiratory droplets, they are usually infrequent. In comparison, speaking and singing generate fewer droplets, but occur much more often, highlighting their potential as a vector for airborne transmission. However, the flow dynamics of speech and the transmission of speech droplets have not been fully investigated. To shed light on this topic, two-dimensional geometries of a vocal tract for a labiodental fricative [f] were generated based on real-time MRI of a subject during pronouncing [f]. In these models, two different curvatures were considered for the tip tongue shape and the lower lip to highlight the effects of the articulator geometries on transmission dynamics. The commercial ANSYS-Fluent CFD software was used to solve the complex expiratory speech airflow trajectories. Simultaneously, the discrete phase model of the software was used to track submicron and large size respiratory droplets exhaled during [f] utterance. The simulations were performed for high, normal, and low lung pressures to explore the influence of loud, normal, and soft utterances, respectively, on the airflow dynamics. The presented results demonstrate the variability of the airflow and droplet propagation as a function of the vocal tract geometrical characteristics and loudness. 

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3. Multimodal Approach for Assessing Neuromotor Coordination in Schizophrenia Using Convolutional Neural Networks

   https://doi.org/10.1145/3462244.3479967  

   Siriwardena, Yashish M.; Espy-Wilson, Carol; Kitchen, Chris; Kelly, Deanna L. (October 2021, Proceedings of the 2021 International Conference on Multimodal Interaction (ICMI ’21))

   This study investigates the speech articulatory coordination in schizophrenia subjects exhibiting strong positive symptoms (e.g. hallucinations and delusions), using two distinct channel-delay correlation methods. We show that the schizophrenic subjects with strong positive symptoms and who are markedly ill pose complex articulatory coordination pattern in facial and speech gestures than what is observed in healthy subjects. This distinction in speech coordination pattern is used to train a multimodal convolutional neural network (CNN) which uses video and audio data during speech to distinguish schizophrenic patients with strong positive symptoms from healthy subjects. We also show that the vocal tract variables (TVs) which correspond to place of articulation and glottal source outperform the Mel-frequency Cepstral Coefficients (MFCCs) when fused with Facial Action Units (FAUs) in the proposed multimodal network. For the clinical dataset we collected, our best performing multimodal network improves the mean F1 score for detecting schizophrenia by around 18% with respect to the full vocal tract coordination (FVTC) baseline method implemented with fusing FAUs and MFCCs. 

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4. Regional tongue deformations during chewing and drinking in the pig

   https://doi.org/10.1093/iob/obab012  

   Olson, Rachel A; Montuelle, Stéphane J; Curtis, Hannah; Williams, Susan H (April 2021, Integrative Organismal Biology)

   Abstract As a muscular hydrostat, the tongue undergoes complex deformations during most oral behaviors, including chewing and drinking. During these behaviors, deformations occur in concert with tongue and jaw movements to position and transport the bolus. Moreover, the various parts of the tongue may move and deform at similar timepoints relative to the gape cycle or they may occur at different timepoints, indicating regional biomechanical and functional variation. The goal of this study is to quantify tongue biomechanics during chewing and drinking in pigs by characterizing intrinsic deformations of the tongue across multiple regions simultaneously. Tongue deformations are generally larger during chewing cycles compared to drinking cycles. Chewing and drinking also differ in the timing of regional length and width, but not total length, deformations. This demonstrates functional differences in the temporal dynamics of localized shape changes whereas the global properties of jaw-tongue coordination are maintained. Finally, differences in the trade-off between length and width deformations demonstrate that the properties of a muscular hydrostat are observed at the whole tongue level, but biomechanical variation (e.g., changes in movements and deformations) at the regional level exists. This study provides new critical insights into the regional contributions to tongue deformations as a basis for future work on multidimensional shape changes in soft tissues. 

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5. Scaling relationships in Formica ants with continuous worker size variation.

   https://doi.org/https://doi.org/10.1007/s00040-020-00779-0  

   Tawdros, S. (January 2020, Insects)

   null (Ed.)

   Social insects exhibit highly variable body plans at multiple scales: within colonies, between conspecific colonies, and across different species. The interspecific variation in the existence and prevalence of morphologically discrete worker subcastes in social insects raises questions about the ontogeny and functional importance of alternative worker body plans. Here, we examine the allometry of four Formica species. Formica are among the most common ants in the northern hemisphere temperate zone, and species vary greatly in the degree of worker size variation. However, no Formica species exhibit obvious worker subcastes. By carefully measuring head width, head height, scape length, thorax length, hind femur length, and hind tibia length in 180 individuals, we confirm that Formica workers exhibit continuous linear scaling, meaning that they lack discrete morphological subcastes. Most measurements scale allometrically. Different colonies of the same species are generally consistent in the slope of these relationships, and we detect unexpected similarities in scaling relationships among the four Formica species as well. Some scaling relationships, including a proportionally shorter scape and larger head in large-bodied workers, were also previously found in fire ants. Identifying worker size and shape distributions among different species is a vital step in understanding the selection pressures shaping division of labor in insect societies. 

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