The question then is how the same neurons convey two different sorts of information. The answer is that motor giants are capable of generating two types of action potentials, small/slow calcium spikes and large/fast sodium spikes, depending on the degree of depolarization it receives. As opposed to the input from the ring giant, the input from the pacemaker is too low to trigger the sodium spik...

This work reports the use of nasal leakage to achieve the pressure difference for voicing in utterance-initial Spanish stops. Multiparametric aerodynamic and acoustic data were analyzed for six Spanish speakers. Two main patterns of prenasalization were identified in postpausal voiced stops: (i) delayed nasal closure relative to the oral closure and (ii) a momentary nasal opening (nasal burst) ...

Certain dialects of Brazilian Portuguese (BP) show signs of nasal coda restoration (NCR). Results of an instrumental study suggest that stressed, word-final nasal vowels terminate in a velar nasal stop, though word-final nasal stops are presumed to be banned in BP. Four BP speakers uttered words ending in a stressed nasal vowel. A split flow mask sampled nasal and oral airflow. Complete oral oc...

This aerodynamic study investigates velum activity during the production of nasal and pharyngeal consonants, using airflow, and during the production of vowels adjacent to nasal and pharyngeal consonants, using airflow and nasalance, in Moroccan Arabic (MA). The results indicate that the velum is lowered during the production of pharyngeals and that this overlaps on adjacent vowels. However, na...

This paper examines the correlation between velar movement and the movement of other articulators in the midsagittal plane. A physiological model is proposed, which, while being based on common knowledge, is more extensive than has been used explicitly to explain observed movements of the velum. The model is used to guide the measurements taken from raw articulatory data provided by Electromagn...

Data on nasal articulation obtained through real-time magnetic resonance imaging (MRI) are jointly used with acoustic analyses of the speech signal to analyze nasal production differences in read and spontaneous speech, especially focusing on the details of acoustic spectral reduction. In this exploratory study, vowel-nasal-vowel (VNV) segments from one speaker were examined and measures corres...

Real-time MRI has become an increasingly useful tool in articulatory studies, especially in examining posterior regions of the vocal tract. Previous work on Brazilian Portugese has shown the emergence of coda consonants following word-final nasal vowels, though this has been limited to the discussion of front vowels and coda emergence in anterior regions of the vocal tract. We present rt-MRI ev...

Population-level genetic diversity in the obligate symbiosis between the bivalve Solemya velum and its thioautotrophic bacterial endosymbiont was examined. Distinct populations along the New England coast shared a single mitochondrial genotype but were fixed for unique symbiont genotypes, indicating high levels of symbiont genetic structuring and potential symbiont-host decoupling.