Segmental and Syllabic Articulations: A Descriptive Approach.

PURPOSE: This article reports on jaw articulation, in connection with the segmental articulations of tongue tip and lips. The jaw is considered a syllable articulator as it opens and closes for each syllable, and the amount of jaw opening is related to syllable strength, given the same phonemic vowel. Here, we investigate the syllabic and the segmental articulations relationships to the acoustic segments. METHOD: We analyze electromagnetic articulography data of 18 Southern Swedish speakers by testing hypotheses based on the Descriptive Approach to Segmental Articulations. In this approach, articulatory movements are divided into fast intervals and steady states, and the crucial ("primary") articulators' deceleration and acceleration peaks align with the acoustic segment boundaries. RESULTS: Previous findings on the lips and the tongue tip are confirmed. New results are the jaw as noncrucial ("nonprimary") does not align with the acoustic segment boundaries: Its steady states are shorter than consonant and vowel segments. Moreover, place of articulation of the coda affects the jaw cycle, while syllable type only affects jaw closing. No such effects are found on the edges of the jaw cycle, instead only gender affects jaw deceleration at syllable onset. CONCLUSIONS: The jaw is not crucial for the timing of the acoustic segment boundaries; also, syllable borders seem to not be affected by place of segmental articulation. The results strengthen the view of the jaw as syllable articulator providing a frame and the other articulators (e.g., lips and tongue tip) as the segmental articulators providing the content.

Rapid movements at segment boundaries.

This paper reports on a one-to-one aspect of the articulatory-acoustic relationship, explaining how acoustic segment boundaries are a result of the rapid movements of the active articulators. In the acceleration profile, these are identified as acceleration peaks, which can be measured. To test the relationship, consonant and vowel segment durations are compared to articulatory posture intervals based on acceleration peaks, and time lags are measured on the alignment of the segment boundaries to the acceleration peaks. Strong relationships and short time lags are expected when the acceleration peaks belong to crucial articulators, whereas weak relationships are expected when the acceleration peaks belong to non-crucial articulators. The results show that lip posture intervals are indeed strongly correlated with [m], and tongue tip postures are strongly correlated with [n]. This is confirmed by the time lag results, which also reveal that the acoustic boundaries precede the acceleration peaks. Exceptions to the predictions are attributed to the speech material or the joint jaw-lip control unit. Moreover, the vowel segments are strongly correlated with the consonantal articulators while less correlated with the tongue body, suggesting that acceleration of crucial consonantal articulators determines not only consonant segment duration but also vowel segment duration.

Word-initial consonant-vowel coordination in a lexical pitch-accent language.

Previous research has acknowledged the effect of prosody on inter-gestural coordination, but specifically the effect of tones is still understudied. This paper has a two-fold purpose. First, it aims to explore effects of the Swedish word accents on word-initial consonant-vowel (CV) coarticulation. Second, it aims to revisit the existing evidence for tonal integration. Based on Articulatory Phonology, it has been suggested that tones - in tone languages - are integrated in the gestural organization of a syllable-initial CV sequence in the same manner as would an additional consonant (CCV), indicated by a time lag between the gestural onsets of the C and the V gesture (CV onset time lag). However, we argue that the existing evidence is inconclusive, because previous cross-linguistic research has used small-scale data sets (one to seven speakers), and we still lack a well-grounded consensus on how gestural onsets are to be measured. This study uses Electromagnetic Articulography (EMA) to investigate word-initial CV coordination in a lexical pitch-accent language (Swedish) with a binary tonal word accent distinction: a tonal fall and a tonal rise, respectively. A selection of 13 spatial, temporal or coordinative measures of bilabial and tongue body data from 19 speakers, and acoustic fo data, were examined to study the CV sequence /ma/. Mixed effects regression models revealed a longer tongue body movement in the rising tone context and small but significant differences in tongue body height, in the closing and the opening of the lips, as well as in the CV onset time lag between the two tonal contexts. We argue that these effects are biomechanical in nature, due to the physiological connections between the tongue, the jaw, and the larynx. In addition, our results suggest either synchronized CV onsets or a CV onset time lag (as in tone languages), depending on the timing landmarks used. In order to evaluate such results as evidence for or against the integration of tone in CV coarticulation, we argue that future research needs to compare data from a variety of languages using a considerable number of speakers. The present study provides new reference values for such comparisons.

Contrasting roles for BMP-4 and ventromorphins (BMP agonists) in TGFß-induced lens EMT.

Transforming growth factor beta (TGFß) and bone morphogenetic protein (BMP) signaling play opposing roles in epithelial-mesenchymal transition (EMT) of lens epithelial cells, a cellular process integral to the pathogenesis of fibrotic cataract. We previously showed that BMP-7-induced Smad1/5 signaling blocks TGFß-induced Smad2/3-signaling and EMT in rat lens epithelial cell explants. To further explore the antagonistic role of BMPs on TGFß-signaling, we tested the capability of BMP-4 or newly described BMP agonists, ventromorphins, in blocking TGFß-induced lens EMT. Primary rat lens epithelial explants were treated with exogenous TGFß2 alone, or in combination with BMP-4 or ventromorphins. Treatment with TGFß2 induced lens epithelial cells to undergo EMT and transdifferentiate into myofibroblastic cells with upregulated α-SMA and nuclear translocation of Smad2/3 immunofluorescence. BMP-4 was able to suppress this EMT without blocking TGFß2-nuclear translocation of Smad2/3. In contrast, the BMP agonists, ventromorphins, were unable to block TGFß2-induced EMT, despite a transient and early ability to significantly reduce TGFß2-induced nuclear translocation of Smad2/3. This intriguing disparity highlights new complexities in the responsiveness of the lens to differing BMP-related signaling. Further research is required to better understand the antagonistic relationship between TGFß and BMPs in lens EMT leading to cataract.