Assessment of a numerical model to reproduce event-scale erosion and deposition distributions in a braided river

Numerical morphological modeling of braided rivers, using a physics-based approach, is increasingly used as a technique to explore controls on river pattern and, from an applied perspective, to simulate the impact of channel modifications. This paper assesses a depth-averaged nonuniform sediment model (Delft3D) to predict the morphodynamics of a 2.5 km long reach of the braided Rees River, New Zealand, during a single high-flow event. Evaluation of model performance primarily focused upon using high-resolution Digital Elevation Models (DEMs) of Difference, derived from a fusion of terrestrial laser scanning and optical empirical bathymetric mapping, to compare observed and predicted patterns of erosion and deposition and reach-scale sediment budgets. For the calibrated model, this was supplemented with planform metrics (e.g., braiding intensity). Extensive sensitivity analysis of model functions and parameters was executed, including consideration of numerical scheme for bed load component calculations, hydraulics, bed composition, bed load transport and bed slope effects, bank erosion, and frequency of calculations. Total predicted volumes of erosion and deposition corresponded well to those observed. The difference between predicted and observed volumes of erosion was less than the factor of two that characterizes the accuracy of the Gaeuman et al. bed load transport formula. Grain size distributions were best represented using two φ intervals. For unsteady flows, results were sensitive to the morphological time scale factor. The approach of comparing observed and predicted morphological sediment budgets shows the value of using natural experiment data sets for model testing. Sensitivity results are transferable to guide Delft3D applications to other rivers.

Phonational profiles of male trained singers and nonsingers

The purpose of this study was to compare the mean speaking fundamental frequency (SFF), speaking frequency range, and mean speaking intensity for a group of trained male singers and a group of age-matched non-singers in three age ranges: 20 to 35 years old; 40 to 55 years old; and older than 65 years. Each subject was recorded as he read "The Rainbow Passage" and produced the vowel /a/ to the limits of his phonational frequency range. The data indicated that the mean SFF of the nonsingers was significantly lower among the middle-aged speakers than with the young or elderly. In contrast, the tenors exhibited no age-related SFF trends, and the young bass/baritones exhibited lower SFF levels than the middle-aged or elderly. The elderly nonsingers produced frequency ranges that were smaller than any other group. Finally, the young nonsingers used greater speech intensity than did the other groups.

Cricoarytenoid arthritis and ankylosing spondylitis

A variety of systemic diseases may manifest with laryngeal symptoms. Cricoarytenoid arthritis with or without limitation of vocal fold motion is an example. It has been described in up to 25% of rheumatoid patients. Ankylosing spondylitis is classified among the seronegative spondylarthritides. Besides its systemic features, rare reports of cricoarytenoid involvement have been published. Six previous cases reported have been characterized by a long history of ankylosing spondylitis before the cricoarytenoid joint involvement occurred. We describe only the seventh case of cricoarytenoid arthritis secondary to ankylosing spondylitis and the first patient (to our knowledge) to present with bilateral vocal fold fixation as the initial presenting symptom.

Phonational profiles of female professional singers and nonsingers

Measures of the SFF, vocal intensity, phonational range, and habitual pitch level are reported for 39 professional singer and 39 nonsinger females, who were divided into three age groups (young, middle, and old age), with the professionals further divided into sopranos and altos. Each read the "Rainbow Passage" and spoke extemporaneously, from which measures of the SFF and vocal intensity were calculated; phonational range and habitual pitch levels were also determined. No significant differences were noted between the reading and speaking tasks. The SFF and intensity levels were significantly higher for the professionals in comparison to the nonsingers, but only for certain age groups. Moreover, whereas the nonsinger SFF levels varied significantly as a function of age, those for the professional singers did not. Although trends occurred, no significant differences were found for the mean phonational range or habitual pitch levels when the professionals and nonsingers were compared.

A comparison of stutterers and nonstutterers in a task of controlled voice onset

The purpose of this study was to determine if stutters and nonstutters differed in their ability to initiate phonation repeatedly with a gentle voice onset. Ten stutterers and ten nonstutterers were asked to phonate the vowel /a/ with an average rise time slower than 52.3 dB/sec while starting the voice at or below 63 dB SPL. Voice productions were monitored by a voice monitor, which is used in the administration of the Precision Fluency Shaping Program. Measurements of number of attempts and time to reach criterion, percentage of correct productions, and intensity levels of each production were made. There were no significant differences between the two groups for any of the variables examined. Results were compared with other studies demonstrating phonatory differences between stutterers and nonstutterers.