scholarly journals Exploring the dimensions of metapopulation persistence: a comparison of structural and temporal measures

2021 ◽  
Author(s):  
Tad A Dallas ◽  
Marjo Saastamoinen ◽  
Otso Ovaskainen
Keyword(s):  
Metapopulation Persistence ◽  
Temporal Measures

Extinction Thresholds and Metapopulation Persistence in Dynamic Landscapes

2000 ◽  
Vol 156 (5) ◽  
pp. 478
Author(s):  
Keymer ◽  
Marquet ◽  
Velasco-Hernández ◽  
Levin
Keyword(s):  
Dynamic Landscapes ◽  
Metapopulation Persistence

scholarly journals Spectral and Temporal Measures in Hybrid Cochlear Implant Users

2012 ◽  
Vol 33 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Justin S. Golub ◽  
Jong Ho Won ◽  
Ward R. Drennan ◽  
Tina D. Worman ◽  
Jay T. Rubinstein
Keyword(s):  
Cochlear Implant ◽  
Temporal Measures

Relationships between the Perception of Nasalization and Speech Movements in Speakers with Cleft Palate

1985 ◽  
Vol 28 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Michael P. Karnell ◽  
John W. Folkins ◽  
Hughlett L. Morris
Keyword(s):  
Cleft Palate ◽  
High Speed ◽  
Posterior Pharyngeal Wall ◽  
The Other ◽  
Pharyngeal Wall ◽  
Acoustic Target ◽  
Temporal Measures ◽  
Target Syllable ◽  
Over Time

The purpose of this study was to examine the relationships between several temporal measures of speech movements and perceived nasalization in speakers with cleft palate. Four adult subjects with repaired cleft palate were filmed using high-speed (100 frames/s) cinefluorography as they produced target syllables embedded in a carrier phrase. Perceived nasalization of each extracted acoustic target syllable was rated by 18 trained judges. Movements of the tongue tip, tongue dorsum, jaw, velar knee, velar tip, and posterior pharyngeal wall were plotted over time. Time of movement onsets and movement offsets was identified from the plots. Voice onset and offset times were identified from the synchronized acoustic recordings. The findings indicate that normally expected velopharyngeal movements occurred near the time of jaw-lowering onset during nasalized CVC and CVN productions in two subjects who were judged to exhibit high levels of nasalization. The other two subjects showed no velopharyngeal movements during the CVC production. It is speculated that velopharyngeal movements normally expected in CVC utterances may be avoided by some speakers with cleft palate in order to minimize perceptible nasalization.

Acoustic Differentiation of Laryngeal, Esophageal, and Tracheoesophageal Speech

1984 ◽  
Vol 27 (4) ◽  
pp. 577-585 ◽  
Author(s):  
Joanne Robbins
Keyword(s):  
Speech Production ◽  
Principal Components ◽  
Discriminant Function Analysis ◽  
Group Membership ◽  
Function Analysis ◽  
Relative Importance ◽  
Vocal Rehabilitation ◽  
Tracheoesophageal Speech ◽  
Components Analysis ◽  
Temporal Measures

This investigation was designed to determine if a multivariate acoustic classifier could effectively discriminate group membership for 15 tracheoesophageal, esophageal, and laryngeal speakers. Seven intensity, 10 frequency, and 13 duration measures were quantified from recorded voice samples. Using principal components analysis, a subset of the 13 least redundant acoustic and temporal measures was systematically selected from the 30 original measures and analyzed singly and jointly in terms of its ability to discriminate among the three speaker groups. Discriminant function analysis revealed perfect categorization of the 45 subjects, indicating that the three methods of speech production are acoustically and temporally distinct from one another. The relative importance of the selected variables which, in combination, significantly differentiated the three groups is discussed in relation to physiologic differences among groups and clinical application for postlaryngectomy vocal rehabilitation.

A (not so) random walk through hydrological space and time

2021 ◽  
Author(s):  
Brian Berkowitz
Keyword(s):  
Random Walk ◽  
Percolation Theory ◽  
Statistical Physics ◽  
Chemical Transport ◽  
Self Organization ◽  
Philosophical Perspective ◽  
Guiding Principle ◽  
Patterns And Processes ◽  
Temporal Measures ◽  
The Relationship

<p>A key philosophical perspective in science is that nature obeys general laws. Identification of these laws involves integration of system conceptualization, observation, experimentation and quantification. This perspective was a guiding principle of John Dalton’s research as he searched for patterns and common behaviors; he performed a broad range of experiments in chemistry and physics, and he entered over 200,000 observations in his meteorological diary during a period of 57 years. In this spirit, we examine general concepts based largely on statistical physics – universality, criticality, self-organization, and the relationship between spatial and temporal measures – and demonstrate how they meaningfully describe patterns and processes of fluid flow and chemical transport in hydrological systems. We discuss examples that incorporate random walks, percolation theory, fractals, and thermodynamics in analyses of hydrological systems – aquifers, soil environments and catchments – to quantify what appear to be universal dynamic behaviors and characterizations.</p>

Temporal Characteristics of Aerodynamic Segments in the Speech of Children and Adults

2002 ◽  
Vol 39 (4) ◽  
pp. 432-438 ◽  
Author(s):  
David J. Zajac ◽  
Alyssa M. Hackett
Keyword(s):  
Older Children ◽  
Total N ◽  
Temporal Characteristics ◽  
Temporal Variables ◽  
Coefficients Of Variation ◽  
Secondary Objective ◽  
Temporal Measures ◽  
Main Effects ◽  
Normal Speech ◽  
Age And Sex

Objectives The primary purpose of this study was to determine the temporal characteristics of aerodynamic segments in the normal speech of children and adults without cleft palate. A secondary objective was to determine the withinspeaker variability of the segments. Method Speakers consisted of 46 children aged 6 to 8 years, 41 older children aged 11 to 12 years, and 41 adults aged 18 to 37 years (total n = 128) who repeated the word “hamper” during continuous utterances. The pressure-flow method was used to determine the duration of six segments of the oral air pressure and nasal airflow pulses associated with the /mp/ sequence. Descriptive statistics, including coefficients of variation (COV), were computed for each segment as a function of age and sex of the speakers. Analysis of variance (ANOVA) procedures were used to determine the effects of age, sex, or both on the temporal variables. Results ANOVAs indicated statistically significant main effects (p < .008) for age on five of the six temporal measures and for sex on three of the six measures. Five of the six COVs were also statistically significant for age. There were no statistically significant interactions between speaker age and sex for any measure. Conclusions The results indicate distinct patterns of timing for aerodynamic segments of speech produced by children and adults. Overall, adults exhibited less temporal variability than children. The generally longer and more variable segments produced by children suggest diagnostic and treatment implications relative to speakers with velopharyngeal dysfunction.

scholarly journals Assessing the roles of seed bank, seed dispersal and historical disturbances for metapopulation persistence of a pyrogenic herb

2019 ◽  
Vol 107 (6) ◽  
pp. 2760-2771 ◽  
Author(s):  
Pedro F. Quintana‐Ascencio ◽  
Stephanie M. Koontz ◽  
Brad M. Ochocki ◽  
Vivienne L. Sclater ◽  
Federico López‐Borghesi ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Seed Bank ◽  
Metapopulation Persistence
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