bluuebunny/crossref_metadata_2025 huggingface dataset:
Perception of musical pitch
Authors: Burns Edward M.
Published: July 2002

Although most of Dix Ward’s publications were concerned with the effects of noise on hearing, his first love was music perception. The publication derived from his doctoral dissertation, ‘‘Subjective musical pitch’’ [J. Acoust. Soc. Am. 26, 369–380 (1954)], is one of the seminal works in the area, as is his treatise on absolute pitch [Sound 2(3), 14–21 (1963); 2(4), 33–41 (1963)]. In these publications, he proved that the performance of certain musicians on pitch tasks, such as ratio production and absolute identification, was an order of magnitude more precise than predicted by the then-current psychophysical ‘‘laws,’’ derived from research on ‘‘normal-hearing’’ subjects. Dix Ward’s research in this area will be discussed, as will recent research which extends and complements his findings. Taken together, this body of work gives empirical evidence for something of which Dix himself was long aware: It is music perception which most closely utilizes the full capabilities of the auditory system; and it is music, rather than speech, which is in fact ‘‘special.’’
Risk assessment for occupational noise induced hearing loss: W. Dixon Ward and the ‘‘Anti-Chicken Little Movement.’’
Authors: Clark William W.
Published: July 2002

One of the hallmarks of W. Dixon Ward’s illustrious career was his proclivity to criticize effectively the efforts of his colleagues. Depending upon the topic and the victim, this ability led him to be characterized as an outstanding editor, a thoughtful reviewer, an overzealous critic, or an impediment to consensus. Despite the variety of responses, Dix’s critiques shared one characteristic: They were almost always correct. One of his favorite targets was the international standard, ‘‘Acoustics—Determination of occupational noise exposure and estimation of noise-induced hearing impairment’’ (ISO 1999, 1990). Throughout the two decades of its development Dix took to task the framers of the standard, challenging the assumptions which underly it. Dix was particularly vexed by ISO’s use of the 3-dB exchange rate, the presumption of 0% risk of noise induced hearing loss for those nonoccupationally exposed, and the estimation that normal 18-year-olds have perfect hearing. In this tribute, Dix’s criticisms of the ISO standard will be articulated and supported with recent data, and his role as the leader of the ‘‘Anti-Chicken Little Movement’’ justified.
High-frequency surface bubble loss
Authors: He Jun , Tappert F. D.
Published: July 2002

The problem of predicting the high-frequency forward propagation loss due to the near-surface bubble layer, called the surface bubble loss (SBL), is solved by use of the full-field University of Miami parabolic equation (UMPE) acoustic model. Curves of SBL versus grazing angle are presented for many wind speeds and frequencies. These results demonstrate the importance of surface-image interference at small grazing angles, an effect that ray-tracing models do not predict. It is also found that the effective surface is displaced downward by the lossy bubble layer, a novel effect that also is not predicted by ray-tracing models. [Work supported by ONR.]
Control of oral closure in alveolar and velar stop consonant production
Authors: Lofqvist Anders , Gracco Vincent L.
Published: July 2002

Earlier work has shown that the lips are moving at a high velocity at the instant of oral closure for bilabial stop consonants, resulting in tissue compression. The lips may thus have virtual targets that would require them to move beyond each other. The present study examines events at the oral closure for stops produced with the tongue. Tongue movements were recorded using a magnetometer system. Four subjects participated and produced ten tokens each of VCV sequences with all possible combinations of the three vowels /i, a, u/ and the consonants /t, d, k, g/. Consistent with the results for bilabial stops, the tongue was moving at a high velocity at the instant of oral closure. The tongue movement trajectories were more complex with a larger horizontal component than the lips. For velar stops, the tongue body was usually moving forward at stop closure, with the velocity influenced by vowel context. For alveolar stops, the tongue tip horizontal movement direction depended on the preceding vowel, but also differed across subjects. Between the onset and release of the oral closure, the tongue tip and tongue body moved through a trajectory of usually less than 1 cm. [Work supported by NIH.]
Analytic implementation of a parabolic equation solution
Authors: Dacol Dalcio K. , Collins Michael D.
Published: July 2002

There are two basic approaches for discretizing the differential equations that are solved in propagation models: (1) Approximate the differential operator with a finite-difference formula; and (2) approximate the medium in terms of layers that may be treated analytically and solve for a set of coefficients. The analytic approach is more efficient for problems involving a small number of layers. Both approaches have been implemented for normal mode and wave-number integration models. The finite-difference approach has been implemented for parabolic equation models. This paper describes an analytic implementation of a parabolic equation model that is efficient for geoacoustic inversion problems [R. J. Cederberg and M. D. Collins, ‘‘Application of an improved self-starter to geoacoustic inversion,’’ IEEE J. Ocean. Eng. (in press)]. Using the finite-difference implementation, the self-starter can solve nonlinear inversion problems in minutes on a workstation (techniques that were developed previously require hours of run time). The analytic implementation reduces run times to seconds. [Work supported by ONR.]
The evolution of single- and double-reed musical instruments: A study of spectral characteristics
Authors: Pyne James , Butler David
Published: July 2002

Most modern orchestral instruments have evolved through many generations of development, in many cases through an evolutionary process spanning hundreds of years. As the process of refinement went on, many earlier instruments were essentially discarded and are now heard only rarely, in early-music concerts. In some cases, these nearly extinct instruments were abandoned because their descendants were much easier to control, or could produce tones spanning increased ranges. In other cases, the earlier instruments may have been discarded because of limitations of their sounds: Their dynamic ranges may have been too limited, or their timbres (tone colors) may have been simply judged unappealing. It may also be the case that these sound characteristics were related: for instance, that the sound of an instrument might have a low ‘‘ceiling’’ of volume and a high ‘‘floor’’ of noise, with the result that the instrument may have produced a fairly weak sound that, when forced to a higher intensity level, rapidly deteriorated in tone quality. This paper will report the early results of a study involving both physical measurements and perceptual judgments of tones produced on early single- and double-reed woodwind instruments.
Expressive performance of jazz ballad melodies
Authors: Ashley Richard
Published: July 2002

This study examines the ways in which jazz musicians use rhythmic alterations of standard ballad melodies for expressive purposes. Without altering a single pitch, these performers take melodies which are so well-known as to be cliched and make them sound fresh. The primary technique is that of extensive rubato, where the melody is played at a varying tempo against the steady rhythmic background of a rhythm section (typically drums, bass, and piano). This results in a displacement of the melodic note relative to its nominal position against the background. Types and degrees of rhythmic variation are shown to depend on motivic structure (parallel motives are performed in similar ways, preserving the originals proportional rhythmic structures), metric emphasis (downbeats are treated differently than other locations), and harmonic structure (melodic tones belonging to the underlying harmonies are rhythmically displaced in a more extreme manner than tones outside the harmonies). Consideration is given to the way in which very familiar tunes are treated compared with less-familiar melodies (for example, ‘‘My Funny Valentine’’ compared with ‘‘Goodbye, Pork-Pie Hat’’), leading to discussion of the role of long-term memory in expressive performance. Analyses are given of several melodies, taken from commercial recordings by master improvisors.
Kinematic characteristics of gestural onsets and the single-geminate consonant distinction in Italian and Finnish
Authors: Hall Dunn Margaret
Published: July 2002

Selspot traces of lip aperture change in the movement-to-closure portions (movement from preceding vowel into consonant) of single and geminate bilabial consonants in two unrelated languages, Italian and Finnish, were assessed to test the hypothesis that geminates are equivalent to sequences of identical overlapping single consonant gestures. If the closing portions of single and geminate consonants exhibited the same kinematic structure, this would be evidence that the geminate is composed of overlapping gestures. Duration of closing movement, displacement during closing, and peak velocity achieved during closing were compared for productions of single and geminate bilabial consonants for four speakers in each language. For Italian, differences in these kinematic variables during the closing portions of singles and geminates could be accounted for in terms of differences in the timing of consonants with respect to preceding vowels and the overlapping-gesture hypothesis was supported; in Finnish the kinematics of the two types of consonants was not equivalent, and it was concluded that Finnish includes a distinct inventory of gestures for the production of long, rather than geminate, consonants. [Work supported by NIH Grant No. DC-00121 to Haskins Laboratories.]
Learning to identify a foreign language
Authors: Bond Z. S. , Stockmal Verna
Published: July 2002

Listeners are able to identify spoken samples of foreign languages at better than chance levels. They are able to do this even when they do not know a language, presumably by using its general phonological properties, that is, its ‘‘acoustic signature.’’ It is not known how much exposure to a foreign language is necessary to learn to identify it. Two experiments were conducted in order to determine the ease with which American listeners could learn to identify the target language, Japanese. The first experiment examined exposure time and materials. Listeners heard word lists or a short children’s story; when tested immediately after exposurse, listeners could identify Japanese interspersed with six other languages better than a control group. The materials did not affect listener performance. In the second experiment, listeners were presented the same materials but tested after a 45-min delay. This task proved much more difficult, although listener performance was marginally better than that of the control group. Apparently, listeners are able to develop a representation of the way a foreign language sounds after a brief exposure, but the representation fades rapidly.
Auditory localization acuity in free field and simulated environments: Reaction time measures
Authors: Buell Thomas N. , Hanna Thomas E.
Published: July 2002

A reaction time measure was used to compare localization acuity in a free field and a simulated environment (where headphone-presented stimuli are processed so as to approximate the waveforms that would occur at each ear canal for a free-field source). Four listeners discriminated the relative direction of a broadband noise (whether it was to the left or right of midline or whether it was in front or back of the interaural axis). The results across four listeners demonstrated that psychometric functions could be plotted for both reaction time as well as percent correct versus angle. Localization was better in the free-field conditions (higher percent correct scores as well as faster reaction times) for front–back discrimination; however, the free-field advantage was negligible for left–right discrimination. Under headphone presentation, there was large inter-subject variability in reaction times for front–back discrimination, but not for left–right discrimination. Although the above findings were not especially surprising, the two metrics did mirror one another in a predictable fashion. The strengths of each procedure will be discussed. [Work supported by NMRDC and ONR, 61153N.MR04101.OOH-5601.]
Signal response of elastically coated plates
Authors: Keltie Richard F.
Published: July 2002

The signal response of a two-dimensional elastic coating attached to a submerged plate has been examined. The coating response was generated by an incident acoustic plane wave impinging on the surface. The main points of interest were the normal and tangential velocity components of the coating response as functions of frequency, signal arrival angle, location through the coating thickness, and coating parameters. Primary attention was focused on developing physical understanding of the processes affecting the coating response, and the mechanisms by which this response could be tailored to achieve desired results. The waveguide behavior of the coating was found to be useful in explaining the signal response. In particular, it was found that the dilatational resonances were useful in explaining the normal velocity response, while the shear resonances were found to be associated with the tangential velocity maxima.
Vibrations of an orthotropic plate with an internal flat circular slot
Authors: Paul H. S. , Venkata Subramanyam M. , Venkatesan M.
Published: July 2002

Vibrations of free and clamped transversely isotropic plates with an internal flat circular slot are studied. According to the physical conditions, the normal stresses become uniform within the circular slot and displacements, and the shearing stresses are zero outside the circular slot. These are mixed boundary value problems which give rise to dual integral equations. Following Noble, the dual integral equations are reduced to Fredholm integral equations. Kernals of the integral equations are evaluated by the contour integration technique. The stress intensity factors are obtained for both cases and corresponding isotropic results are deduced. Numerical analysis is performed in the case of Beryl material. The relationship between the dimensionless frequency and the stress intensity factor is presented. The results thus obtained are discussed.
Regularized modal decomposition for matched-mode processing
Authors: Dosso Stan E. , Collison Nicole E.
Published: July 2002

Long-range acoustic propagation in the ocean is often well modeled by a discrete set of propagating normal modes. When this is the case, the acoustic field measured at an array of sensors can be decomposed into its modal components providing the basis for matched-mode processing (MMP) methods. Modal decomposition represents a discrete linear inverse problem. For vertical arrays which do not adequately sample the water column or for horizontal arrays, the inverse problem is ill-conditioned and modal decomposition can lead to poor results for noisy measurements. Regularization is a technique for stabilizing inverse problems based on trading off minimizing the data residuals (misfit) with minimizing some function of the solution. In the case of modal decomposition for MMP, an appropriate choice for the regularizing function is the deviation of the modal excitations of the solution from those of the replica field at each trial source location. This results in the best possible match between the measured and replica mode excitations given the noise and array characteristics and can lead to substantial improvements in MMP.
Prediction of cooling tower noise emissions
Authors: Ferren W. Brent , Dicke Andrew P.
Published: July 2002

Cooling towers are commonly significant contributors to the overall noise emitted by power generation facilities. Because power generation facilities are often required to meet strict environmental noise criteria, predicting the potential noise impact of the cooling tower during the design of the facility is important in developing noise mitigation strategies. The prediction technique must accurately simulate the noise radiation pattern associated with the cooling tower. The main components of noise associated with mechanical draft cooling towers generally include the water falling over the fill media, the operation of the fan units, and the operation of the circulating water pumps. This paper summarizes a study of cooling tower noise modeling techniques frequently used to simulate sound propagation. The noise emitted from a mechanical draft cooling tower is modeled by various directional point source configurations to account for each noise component. Additionally, the noise barrier effect of the cooling tower is included. The noise impact predicted by the cooling tower models are compared to field sound level measurements in order to evaluate the effectiveness of the cooling tower models.
A time-domain description of the thermoacoustic instability
Authors: Karpov Sergey , Prosperetti Andrea
Published: July 2002

In typical conditions the time scale for the development of the thermoacoustic instability in a tube is slow compared with the acoustic period. It is therefore possible to solve the problem by the method of multiple time scales. In this way a time-domain description of the process is obtained. The perturbation results are compared with the exact solution of the linear problem and their range of validity is discussed. It is found that they are accurate only when the spacing of the plates in the stack is sufficiently large. The ‘‘short-stack approximation’’ is also introduced and evaluated with comparable results, provided the effective wave number is chosen appropriately. [Work supported by the Office of Naval Research.]
Muscle-based modeling of facial dynamics during speech
Authors: Lucero Jorge C. , Munhall Kevin G. , Vatikiotis-Bateson Eric , Gracco Vincent L. , Terzopoulos Demetri
Published: July 2002

A dynamical, muscle-based model of the face is being developed to extend the facial model of Terzopoulos et al. [e.g., D. Terzopoulos and K. Waters, IEEE Trans. Pattern Anal. Machine Intell. 15, 569–579 (1993)]. The purpose of this work is to characterize facial dynamics during speech with a physiologically realistic model. The model consists of a multilayered deformable mesh of lumped masses connected by springs and viscous elements which represents the layered structure of facial tissue. The spring and viscous constants approximate the stress/strain and viscous characteristics of facial skin. The mesh is deformed by forces generated by a set of modeled muscles of facial expression whose physical characteristics are being determined empirically. The shape of the facial model is individualized to subjects facial morphology with data from a laser ranger finder (Cyberware scanner). In this report, work on driving the model with intramuscular, perioral EMG signals is presented. Recordings of the sampled three-dimensional position of a subject’s facial surface using OPTOTRAK are compared to the patterns of deformation of the epidermal mesh in the model. Results will be discussed in terms of the strengths and weaknesses of this modeling approach. [Work supported by NIH-NIDCD Grant No. DC-00594 and NSERC.]
Two types of vowel devoicing in Japanese: Evidence from articulatory data
Authors: Tsuchida Ayako , Kiritani Shigeru , Niimi Seiji
Published: July 2002

Japanese high vowels [i, u] become devoiced when they occur between voiceless segments: e.g., [kita] ‘‘north.’’ Vowel devoicing (VD) occurs systematically, except when a high vowel appears between two voiceless fricatives, where VD is less consistent and nonobligatory. The present study examined the laryngeal gestures during the production of Japanese vowels in various phonological contexts using fiberscopic and electromyographic techniques. Stimuli consisted of [CiCe] words, where the consonants were stops (S) or fricatives (F). The results revealed that the glottal gestures for typical devoiced vowels (those in [SiSe], [FiSe], or [SiFe]) and devoiced vowels in [FiFe] were distinct, although the two types were indistinguishable in the spectrograms. Consistent with observations in a previous study [H. Hirose, Phonetica 23, 156–170 (1971)], [CiC] sequences with typical devoiced vowels were produced with a wide open glottis accompanied with high activities of the abductor muscle. In contrast, in [FiF] sequences, the glottis was wide open in each of the fricatives, but was almost closed during the vowel, resulting in a bimodal pattern. When the glottis reached complete closure during the vowel, a voiced vowel was observed. The present study shows two distinct mechanisms for VD, suggesting that they are two independent processes.
Positional dependence on localization dominance in the median-sagittal plane
Authors: Dizon Robert M. , Litovsky Ruth Y. , Colburn H. Steven
Published: July 2002

Previous experiments by the authors investigated aspects of the precedence effect in both the azimuthal and median-sagittal planes in a virtual acoustic environment. Among the aspects studied was localization dominance; where the location of a lead-lag combination is dominated by the leading source. It was apparent that the virtual presentation was not providing an adequate elevation percept in the median plane, possibly due to the use of nonindividualized head-related transfer functions. Nonetheless, subjects, who were given feedback, were able to use timbral differences in the fused lead-lag pairs to perform the task. The results of similar median plane studies in a free-field anechoic condition are reported on, where location percepts are more robust. Preliminary results show position-dependent biases, where some lead positions (front) show greater amounts of localization dominance over certain lag positions (overhead). Frontal dominance has been shown in previous work in the median plane (Rakerd and Hartmann, personal communication). It is postulated that some positions in the median plane are dominant, and that in a competition paradigm such as localization dominance, the amount of dominance given to the lead would be dependent on the locations of the leading and lagging stimuli. [Work supported by NIH Grant Nos. DC02692 and DC00100.]
Radiation from point sources within a bubble cloud
Authors: Means Steven L. , Heitmeyer Richard M.
Published: July 2002

Bubble cloud resonances have been proposed as an explanation of the low-frequency acoustic radiation produced by breaking waves. A previous model [H. N. Og̃uz, J. Acoust. Soc. Am. 95, 1895–1912 (1994)] considered excitation of the bubble cloud by a rigid piston at the base of a hemispherical bubble cloud. The present model considers excitation of the cloud by individual points sources within the cloud. A Green’s function is obtained for a point source displaced from the origin of a hemispherical bubble cloud beneath a pressure release surface. The radiation pattern for multiple point sources distributed within a slice of the hemispherical cloud is obtained by superposition and the method of images. The effects of bubble cloud characteristics on the radiation field will be shown for various frequencies and ranges of point source depths. The method presented here is applicable to modeling sound generation of breaking waves having bubble clouds that are not amenable to being modeled by a hemispherical geometry. For instance, bubble clouds produced by breaking surf might be modeled more accurately using a cylindrical bubble cloud geometry. [Work supported by ONR.]
On the use of acoustic ambient noise to characterize backscattering strength
Authors: Day Christopher W. , Williams Neil J. , Monjo Charles L. , Nguyen Hien B. , Deferrari Harry A.
Published: July 2002

Strong correlation between acoustic ambient noise and backscattering strength was observed during analysis of data from the acoustic surface reverberation experment (ASREX) [Williams et al., J. Acoust. Soc. Am. 97, 3404 (1995)]. Traditional empirical formulas for acoustic backscattering strength, such as those of Chapman and Harris [R. P. Chapman and J. H. Harris, J. Acoust. Soc. Am. 34, 1592–1597 (1962)] and Ogden and Erskine [P. M. Ogden and F. T. Erskine, J. Acoust. Soc. Am. 95, 746–761 (1994)], utilize wind speed, frequency, and grazing angle as their input variables. An alternative approach which utilizes ambient noise in place of wind speed is presented here. Unlike wind speed, ambient noise measurements are easily made from subsurface platforms and this technique may therefore be advantageous for certain applications (i.e., submarines and covert operations). [Work supported by ONR.]
Modeling and simulation of marine mammal generated sound. I. Stochastic modeling of marine mammal spatial distributions, collective motions, and vocalization occurrence times
Authors: Hayward Thomas J.
Published: July 2002

Stochastic models and algorithms are developed for representing and simulating marine mammal spatial distributions, collective motions, and vocalization occurrence times. A general class of Markov-process models of collective motion is first identified. Within this class, particular representations are constructed that incorporate interaction mechanisms of the type developed in distributed behavior modeling [C. Reynolds, Comput. Graph. 21, 25 (1987)]. Collective motion is represented by a Markov process with a stationary probability density defined in terms of an ‘‘energy’’ function that expresses the propensity for clustering and polarization within groups of individuals. Computer-generated sample functions of the Markov processes, based on variants of the Metropolis algorithm, provide for simulation of a variety of collective motions. These range from nearly independent motions of solitary individuals to motions in highly clustered and polarized configurations simulating motions of marine mammals in pods. Occurrence times of vocalizations are represented by Markov processes and associated simulation algorithms. Simulations of patterned click sequences (codas) [Watkins and Schevill, J. Acoust. Soc. Am. 62, 1485 (1977)] produced by sperm whales (Physeter catodon) are presented as an example. Potential applications to sonar systems and marine mammal acoustic surveys are briefly discussed. [Work supported by ONR and NRL.]
Environmental impact on active-sonar performance predictions in shallow water
Authors: Leclere James H. , Collins Mona J. , Del Balzo Donald R.
Published: July 2002

Predictions of active-sonar system performance at 750 Hz and 3 kHz in shallow water were reported [J. H. Leclere et al., J. Acoust. Soc. Am. 100, 2604(A) (1996)] using a simple propagation model (FAME) in reverberation-limited situations. The water sound-speed profiles and bottom geoacoustic descriptions were derived from historical data collected in the Strait of Sicily. This analysis extends the previous work with more accurate propagation calculations (RASP) and the inclusion of signal spreading in harsh bottom-limited environments. Transmission loss, reverberation level, signal spreading (echo splitting loss), and signal excess for a generic sonar system are calculated for several realistic environmental descriptions in 100- and 800-m water depths. The sensitivity of sonar system predictions to spatial environmental variations are quantified and implications about space sampling strategies are discussed. [Work supported by ONR/NRL.]
Where lipreaders look on the face: Task and individual differences
Authors: Lansing Charissa R. , McConkie George W.
Published: July 2002

Lipreaders’ eye movements were monitored in real time to determine where they direct their attention on the speaker’s face to obtain linguistically relevant information for speech perception. Full-motion video sequences displaying a full-face view of a male speaker were presented without sound to proficient lipreaders who were deaf or hearing. A still frame of the speaker’s face was displayed for 1 s preceding and following each video segment. The video was followed by a display of a written sentence that was identical or different from the sentence produced by the speaker. Lipreaders indicated same/different by pressing a button. Results indicate that eye gaze was most often directed at the mouth as the speaker produced the sentence but occasionally moved to other parts of the face. The number of these off-mouth gazes during speech varied among lipreaders and with sentence characteristics. Both task and lipreader characteristics influence where people look for information on the face of the speaker. [Work supported by NIDCD, NIH.]
Speech reception thresholds in noise with and without spectral and temporal dips for hearing-impaired and normally hearing people
Authors: Peters Robert W. , Moore Brian C. J. , Baer Thomas
Published: July 2002

Normally hearing people have much lower speech reception thresholds (SRTs) in a background of a single talker than in the background of speech-shaped noise, whereas hearing-impaired people do not. The hearing impaired appear to be less able than normal to take advantage of temporal and spectral ‘‘dips’’ in interfering speech. SRTs were measured in background sounds that varied to the extent that they contained such dips. The subjects tested were: (a) young with normal hearing; (b) elderly with near-normal hearing; (c) young with moderate to severe cochlear hearing loss and (d) elderly with moderate to severe cochlear hearing loss. In a background that contained both spectral and temporal dips, the hearing-impaired and elderly with near-normal hearing performed much more poorly than normals. The signal-to-background ratio required for 50% intelligibility was about 19 dB higher for elderly hearing impaired than for young normals. Young hearing-impaired subjects showed a slightly smaller deficit, but still a substantial one. Linear amplification combined with appropriate frequency-response shaping (NAL amplification) only partially compensated for these deficits. It is proposed that noise with spectral and temporal dips provides a potentially useful way of evaluating the effects of signal processing such as frequency-selective amplification and compression.
The mismatch negativity auditory evoked potential: A reflection of acoustic or phonetic difference detection?
Authors: Dalebout Susan D. , Stack Janet W.
Published: July 2002

The mismatch negativity (MMN) auditory evoked potential reflects detection of minimal stimulus differences at a pre-attentive level. It has been reported that the MMN reflects acoustic, rather than phonetic, processing of speech stimuli [Sharma et al., Electroenceph. and Clin. Neurophys. 88, 64–71 (1993)]. If this is true, then every stimulus pair from a continuum along which the acoustic differences between each step are equivalent should elicit an equivalent MMN, even when the acoustic differences are not perceptible to the listener (e.g., within-category differences). In this study, stimuli were two-step syllable pairs taken from a nine-step synthetic continuum varying in place of articulation from /da/ to /ga/. Results of conventional labeling and discrimination tasks demonstrated that the stimuli were categorically perceived. The MMN was tested using three stimulus pairs: a pair in which syllables were not perceptibly different (items seven and nine, a within-category distinction), the pair best discriminated (behaviorally) by each individual subject (a between-category distinction), and a pair comprising the endpoints of the continuum (items one and nine). Results are discussed in terms of their implications for using the MMN as an objective measure of speech discrimination ability and as a tool for studying aspects of speech perception.
High-frequency asymptotic description of head waves and boundary layers surrounding the critical rays in an elastic half-space
Authors: Gridin Dmitri
Published: July 2002

The high-frequency asymptotic description of head waves as well as the field inside boundary layers surrounding the critical rays are obtained for two cases: (a) a point source, and (b) a circular transducer, both acting normally on an isotropic and homogeneous elastic half-space. The edge head waves underneath a circular transducer are described by the asymptotics of a higher order compared to those of direct compressional, edge compressional, and shear waves, but are still discernible in the radiating near zone and thus might be useful in nondestructive evaluation of industrial materials. The asymptotic formulas produced involve in geometrical zones elementary functions and inside boundary layers well-known special functions. Therefore, they allow us to elucidate the physics of the problem and can be used in writing computer codes which simulate the radiating near field of a circular transducer orders of magnitude faster than full numerical schemes. The formulas have been tested against exact integral solutions evaluated numerically.
Preferred self-to-other ratios in choir singing
Authors: Ternström Sten
Published: July 2002

Choir singers need to hear their own voice in an adequate self-to-other ratio (SOR) over the rest of the choir. Knowing singers’ preferences for SOR could facilitate the design of stages and of choral formations. In an experiment to study the preferred SOR, subjects sang sustained vowels together with synthesized choir sounds, whose loudness tracked that of their own voice. They could control the SOR simply by changing their distance to the microphone. At the most comfortable location, the SOR was measured. Experimental factors included unison and four-part tasks, three vowels and two levels of phonation frequency. The same experiment was run four times, using sopranos, altos, tenors, and basses, with stimulus tones adapted for each category. The preferred self-to-other ratios were found to be similar to SORs measured previously in actual performance, if a little higher. Preferences were quite narrow, typically ±2 dB for each singer, but very different from singer to singer, with intrasubject means ranging from −1 to +15 dB. There was no significant difference between the unison and the four-part tasks, although this might have been caused by systematic differences in the stimulus sounds. Some effects of phonation frequency and vowel were significant, but interdependent and difficult to interpret. The results and their relevance to live choir singing are discussed.
Textural analysis of sidescan sonar imagery and generic seafloor characterization
Authors: Blondel Philippe
Published: July 2002

Sidescan sonar imagery is a primordial component of geophysical and environmental surveys of the seafloor. Most of the data are still interpreted visually and qualitatively by experts. The method presented here uses textural analysis, and supplements the interpreter with reliable quantitative results. Indices are derived from grey-level co-occurrence matrices, whose mathematical expressions have been adapted to the specifics of sidescan sonar imagery. The indices measure the different properties of the acoustic textures and correlate them with the characteristics of the seafloor. This technique, called TexAn, has been extensively ground-truthed in complex midocean ridge terrains, using submersible and ROV observations, and in situ sampling. The frequencies used so far range from 6.5 to 500 kHz; all applications have been validated and ground-checked. Current applications are mainly concerned with the geology of midocean ridges, continental margins, and coastal waters. The technique has also been demonstrated for the detection of mines and subsurface structures. Being hardware-independent, TexAn enables quantitative assessments of sidescan sonar imagery, at all stages of processing and in all conditions. Another advantage of TexAn is the detection of details hitherto invisible to the human eye, however experienced.
RhoA regulation in space and time
Authors: de Seze Jean , Gatin Joséphine , Coppey Mathieu
Published: January 2023

RhoGTPases are well known for being controllers of cell cytoskeleton and share common features in the way they act and are controlled. These include their switch from GDP to GTP states, their regulations by different guanine exchange factors (GEFs), GTPase‐activating proteins and guanosine dissociation inhibitors (GDIs), and their similar structure of active sites/membrane anchors. These very similar features often lead to the common consideration that the differences in their biological effects mainly arise from the different types of regulators and specific effectors associated with each GTPase. Focusing on data obtained through biosensors, live cell microscopy and recent optogenetic approaches, we highlight in this review that the regulation of RhoA appears to depart from Cdc42 and Rac1 modes of regulation through its enhanced lability at the plasma membrane. RhoA presents a high dynamic turnover at the membrane that is regulated not only by GDIs but also by GEFs, effectors and a possible soluble conformational state. This peculiarity of RhoA regulation may be important for the specificities of its functions, such as the existence of activity waves or its putative dual role in the initiation of protrusions and contractions.
NASADAD update on Synar: Raising the age, and COVID‐19
Authors: Knopf Alison
Published: January 2023

The National Association of State Alcohol and Drug Abuse Directors (NASADAD) last week released an updated fact sheet for provisions of the Synar Amendment, including revisions made as a result of COVID‐19. The Synar Amendment, named for the late former Congressman Mike Synar (D‐Okla.), requires states to prohibit the sale or distribution of tobacco products to minors. The update, by NASADAD's Lacy Adams, noted the following events.
Stride‐to‐Stride Fluctuations of Human Gait Are Affected By Chronobiology: An Exploratory Study
Authors: Vaz João R. , Silva Luís M. , Stergiou Nick
Published: January 2023

Physiological processes present daily oscillations of ≈24 h, called circadian rhythms. Motor performance, for example, reaches its peak in the afternoon, although this can be affected by chronotype. Certain motor activities, for example, walking, can also be affected by circadian rhythms. Healthy walking exhibits stride‐to‐stride fluctuations with a fractal‐like structure that enables adaptability. While pathology and aging are shown to lead to random‐like fluctuations; and, therefore, decreased adaptability; the influence of circadian rhythms remains unknown. This study investigates how these fluctuations present in healthy gait are affected by the time of day and chronotype. Eighteen young adults walk for 10 min every 2 h, from 8 a.m. to 6 p.m. Footswitches are used to determine heel‐strike and calculate stride time. Then, detrended fluctuation analysis is used to calculate fractal scaling. A mixed‐model Analysis of Variance is used and followed by a backward stepwise elimination process. Tukey's tests are used for pairwise comparisons. The statistical model shows the effect of time during the day (12 p.m. exhibits a higher fractal scaling compared to 8 a.m.); and chronotype (evening‐types exhibit higher fractal scaling compared to morning‐types). This study reveals the influence of chronobiology on stride‐to‐stride fluctuations. These findings open new perspectives to integrate circadian medicine in biomechanics.
Acetyl‐11‐keto‐β‐boswellic Acid Confers Protection in DSS‐Induced Colitis via the JNK–p38 MAPK and NF‐κB Signaling Pathways
Authors: Zhang Peng , Jiang Hua
Published: January 2023

The present study aims to explore the effect and mechanism of acetyl‐11‐keto‐β‐boswellic acid (AKBA) on inflammatory bowel disease (IBD). The IBD‐mouse model is established by replacing normal water intake with 2.5% dextran sulfate sodium salt (DSS) aqueous solution, and 50 mg kg−1 of AKBA treatment is administered. The experimental mice are randomly divided into four groups, including control, AKBA , DSS, and DSS + AKBA groups. AKBA therapy conspicuously ameliorates the adverse symptoms caused by DSS in mice and inhibits the reduction of colon length and the rise of disease activity index score. Hematoxylin–eosin staining results suggest that AKBA strikingly improves the pathological conditions of the colon and small intestine tissues in IBD mice. AKBA prominently inhibits the DSS‐induced increase of proinflammatory factor contents and the upregulation of the c‐Jun N‐terminal kinase (JNK)–p38/mitogen‐activated protein kinase (MAPK) and Nuclear factor kappa B (NF‐κB) pathways’ protein levels in the colon tissues of IBD mice. AKBA alleviates DSS‐induced colonic inflammatory injury in IBD mice by repressing the activation of the JNK–p38/MAPK and NF‐κB pathways.
Bioengineering and Clinical Translation of Human Lung and its Components
Authors: Derman Irem Deniz , Singh Yogendra Pratap , Saini Shweta , Nagamine Momoka , Banerjee Dishary , Ozbolat Ibrahim T.
Published: January 2023

Clinical lung transplantation has rapidly established itself as the gold standard of treatment for end‐stage lung diseases in a restricted group of patients since the first successful lung transplant occurred. Although significant progress has been made in lung transplantation, there are still numerous obstacles on the path to clinical success. The development of bioartificial lung grafts using patient‐derived cells may serve as an alternative treatment modality; however, challenges include developing appropriate scaffold materials, advanced culture strategies for lung‐specific multiple cell populations, and fully matured constructs to ensure increased transplant lifetime following implantation. This review highlights the development of tissue‐engineered tracheal and lung equivalents over the past two decades, key problems in lung transplantation in a clinical environment, the advancements made in scaffolds, bioprinting technologies, bioreactors, organoids, and organ‐on‐a‐chip technologies. The review aims to fill the lacuna in existing literature toward a holistic bioartificial lung tissue, including trachea, capillaries, airways, bifurcating bronchioles, lung disease models, and their clinical translation. Herein, the efforts are on bridging the application of lung tissue engineering methods in a clinical environment as it is thought that tissue engineering holds enormous promise for overcoming the challenges associated with the clinical translation of bioengineered human lung and its components.
Creation of Assembled Plasmonic Network Architectures with Selective Capture of Guest Molecules in Hotspots Region
Authors: Sun Fuwei , Tian Li , He Guokang , Gao Ning , Zhao Hongwei , Liu Weigang , Liu Chao , An Qi , Wang Chen , Li Guangtao
Published: January 2023

Plasmonic networks attract increasing attention owing to their strong plasmon coupling effects at hotspot regions, where intriguing, collective optical behavior and field enhancement occur. Engineering network architectures with flexible control over density and intensity of hotspots, thus fine‐tuning electromagnetic field is the prerequisite for fully exploiting their potential use in diverse plasmon‐based applications, but it represents a great challenge. Herein, a cage‐assisted bottom‐up self‐assembly strategy is proposed to construct a series of cage‐bridged complex network architectures with a high degree of flexibility in hotspot modulation. Critical parameters associated with plasmonic networks, including interparticle distance, the density and intensity of hotspots, as well as molecule accessibility of hotspot can be simultaneously and flexibly adjusted at will. Importantly, the integration of host–guest chemistry of molecular cages into interparticle regions of networks endows selective molecule trapping capability in hotspots, offering tremendous opportunities for broader plasmon‐based applications. The present study not only develops efficient plasmonic networks with enhanced density of hotspots and intense electromagnetic fields, but also provides new avenues for artificially engineering network architectures with advanced functionalities and facilitates further applications in sensing and optoelectronics.
Investigation of CdSe and ZnSe as Potential Back Surface Field Layers for CdTe‐Based Solar Cells: A Study from First Principles Calculations
Authors: Ray Subhasmita , Tarafder Kartick
Published: January 2023

A class of II–VI semiconductors, especially CdTe, is a highly photo‐reactive compound that would be suitable for photovoltaic applications. However, being a highly resistive material, CdTe produces considerable contact resistance and drastically reduces the efficiency of photovoltaic devices. Introducing a back surface field layer at the contact region may significantly improve the device's performance. This work investigates the suitability of using ZnSe and CdSe layer as a back‐surface‐field layer in CdTe‐based solar cells through accurate electronic structure calculations using the hybrid‐density functional theory method. The calculations show that both ZnSe/CdTe and CdSe/CdTe behave as type‐II heterojunctions with band gaps of 2.0 and 1.1 eV, respectively. The Mulliken electronegativity method is used to determine the correct band edge positions concerning the vacuum level for all the pristine semiconductors and their interfaces. Calculation shows that a significant charge redistribution in the interface leads to the formation of an effective local field near the contact region for both ZnSe/CdTe and CdSe/CdTe heterostructures. This local field may help to separate the photogenerated electron–hole pairs in the active layer by pushing the opposite charges into the two different sections of the heterojunction. Additionally, the heterojunctions also exhibit better light‐absorption characteristics in the visible light range.
Cancer Cells Enter an Adaptive Persistence to Survive Radiotherapy and Repopulate Tumor
Authors: Zhao Yucui , Lu Tingting , Song Yanwei , Wen Yanqin , Deng Zheng , Fan Jiahui , Zhao Minghui , Zhao Ruyi , Luo Yuntao , xie Jianzhu , Hu Binjie , Sun Haoran , Wang Yiwei , He Sijia , Gong Yanping , Cheng Jin , Liu Xinjian , Yu Liang , Li Jikun , Li Chuanyuan , Shi Yongyong , Huang Qian
Published: January 2023

Repopulation of residual tumor cells impedes curative radiotherapy, yet the mechanism is not fully understood. It is recently appreciated that cancer cells adopt a transient persistence to survive the stress of chemo‐ or targeted therapy and facilitate eventual relapse. Here, it is shown that cancer cells likewise enter a “radiation‐tolerant persister” (RTP) state to evade radiation pressure in vitro and in vivo. RTP cells are characterized by enlarged cell size with complex karyotype, activated type I interferon pathway and two gene patterns represented by CST3 and SNCG. RTP cells have the potential to regenerate progenies via viral budding‐like division, and type I interferon‐mediated antiviral signaling impaired progeny production. Depleting CST3 or SNCG does not attenuate the formation of RTP cells, but can suppress RTP cells budding with impaired tumor repopulation. Interestingly, progeny cells produced by RTP cells actively lose their aberrant chromosomal fragments and gradually recover back to a chromosomal constitution similar to their unirradiated parental cells. Collectively, this study reveals a novel mechanism of tumor repopulation, i.e., cancer cell populations employ a reversible radiation‐persistence by poly‐ and de‐polyploidization to survive radiotherapy and repopulate the tumor, providing a new therapeutic concept to improve outcome of patients receiving radiotherapy.