bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalized collar waves and their characteristics
Authors: Wang Xiuming , He Xiao , Zhang Xiumei
Published: October 2014

A good acoustic logging while drilling (ALWD) tool is difficult to be designed because of collar waves that propagate along the tool. There always exist such acoustic waves in ALWD. The collar wave arrivals can strongly interfere with formation compressional waves in wave slowness picking up. In the past years, a considerable research work has been seen in suppressing collar waves in order to accurately pick up p- and s-wave slowness, and the obtained p- and s-wave slowness accuracy is still a problem. In this work, numerical and physical experiments are conducted to tackle collar wave propagation problems. And the collar wave propagation physics is elaborated and a generalized collar wave concept is proposed. It is shown that collar waves are much complex, and they consist of two kinds of collar waves, i.e., the direct collar waves and indirect collar waves. Both of these two collar waves make the ALWD data difficult to process for formation wave slowness picking up. Because of drilling string structures, the complicated collar waves cannot be effectively suppressed only with a groove isolator.
Difference frequency scattered waves from nonlinear interactions of a solid sphere
Authors: Nguon Chrisna , Denis Max , Chandra Kavitha , Thompson Charles
Published: October 2014

In this work, the generation of difference frequency waves arising from the interaction of dual-incident beams on a solid sphere is considered. The high-frequency incident beams induce a radiation force onto the fluid-saturated sphere causing the scatterer to vibrate. An analysis on the contribution between the difference frequency sound and radiation force pressure is of particular interest. The scattered pressure due to the two primary waves are obtained as solutions to the Kirchhoff–Helmholtz integral equation for the fluid–solid boundary. Due to the contrasting material properties between the host fluid and solid sphere, high-order approximations are used to evaluate the integral equation.
Effect of surface irregularities on the stability of Stokes boundary
Authors: Aho Katherine , Au Jenny , Thompson Charles , Chandra Kavitha
Published: October 2014

In this work, we examine that impact that wall surface roughness plays on the stability of an oscillatory Stokes boundary layer. The temporal growth of three-dimensional disturbances excited by wall height variations is of particular interest. Floquet theory is used to identify linearly unstable region in parameter space. It is shown that disturbances become unstable at critical value of the Taylor number for a given surface curvature. The case of oscillatory flow in a two-dimensional rigid walled channel is considered in detail.
The role of subglottal acoustics in speech production and perception
Authors: Sommers Mitchell , Alwan Abeer , Lulich Steven
Published: October 2014

In this talk, we present an overview of subglottal acoustics, with emphasis on the significant anatomical structures that define subglottal resonances, and we present results from our experiments incorporating subglottal resonances into automatic speaker normalization and speech recognition technologies. Speech samples used in the modeling and perception studies were obtained from a new speech corpus (the UCLA-WashU subglottal database) of simultaneous microphone and (subglottal) accelerometer recordings of 50 adult speakers of American English (AE). We will discuss new findings about the Young's Modulus of tracheal soft tissue, the viscosity of tracheal cartilage, and the effect of going from a circular cross-section to a rectangular cross-section in the conus elasticus. We also present results from studies demonstrating a small, but significant, role of subglottal resonances in discriminating speaker height and of the interaction between subglottal resonances and formants in height discrimination.
The effect of subglottal acoustics on vocal fold vibration
Authors: Titze Ingo R. , Titze Ingo R.
Published: October 2014

Acoustic pressures above and below the vocal folds produce a push-pull action on the vocal folds which can either help or hinder vocal fold vibration. The key variable is acoustic reactance, the energy-storage part of the complex acoustic impedance. For the subglottal airway, inertive (positive) reactance does not help vocal fold vibration, but helps to skew the glottal airflow waveform for high frequency harmonic excitation. Compliant (negative) reactance, on the contrary, helps vocal fold vibration but does not skew the waveform. Thus, the benefit of subglottal reactance is mixed. For supraglottal reactance, the benefit is additive. Inertive supraglottal reactance helps vocal fold vibration and skews the waveform, whereas compliant supraglottal reactance does neither. The effects will be demonstrated with source-filter interactive simulation.
Effects of spectral smearing on sentence recognition by adults and children
Authors: Lowenstein Joanna H. , Tarr Eric , Nittrouer Susan
Published: October 2014

Children’s speech perception depends on dynamic formant patterns more than that of adults. Spectral smearing of formants, as found with the broadened auditory filters associated with hearing loss, should disproportionately affect children because of this greater dependence on formant patterns. Making formants more prominent, on the other hand, may result in improved recognition. Adults (40) and children age 5 and 7 (20 of each age) listened to 75 four-word syntactically correct, semantically anomalous sentences processed so that excursions around the mean spectral slope were sharpened by 50% (making individual formants more prominent), flattened by 50% (smearing individual formants), or left unchanged. These sentences were presented to children and to half of the adults in speech-shaped noise at 0 dB SNR. The rest of the adults listened to the sentences at -3 dB SNR. Results indicate that all listeners did more poorly with the smeared formants, with 5-year-olds showing the largest decrement in performance at 0 dB SNR. However, adults at -3 dB SNR showed an even greater decrement in performance. Making formants more prominent did not improve recognition, perhaps due to harmonic-formant mismatches. Thus, there is reason to explore processing strategies that might enhance formant prominence for listeners with hearing loss.
Developmental and linguistic factors of audiovisual speech perception across different masker types
Authors: Reetzke Rachel , Lam Boji , Xie Zilong , Sheng Li , Chandrasekaran Bharath
Published: October 2014

Developmental and linguistic factors have been found to influence listeners’ ability to recognize speech-in-noise. However, there is paucity of evidence exploring how these factors modulate speech perception in everyday listening situations, such as multisensory environments and backgrounds with informational maskers. This study assessed sentence recognition for 30 children (14 monolingual, 16 simultaneous bilingual; ages 6–10) and 31 adults (21 monolingual, ten simultaneous bilingual; ages 18–22). Our experimental design included three within-subject variables: (a) masker type: pink noise or two-talker babble, (b) modality: audio-only and audiovisual, and (c) signal-to-noise ratio (SNR): 0 to -16 dB. Results revealed that across both modalities and noise types, adults performed better than children, and simultaneous bilinguals performed similarly to monolinguals. The age effect was largest at the lowest SNRs of -12 and -16 dB in the audiovisual two-talker babble condition. These findings suggest that children experience greater difficulty in segregation of target speech in informational maskers relative to adults, even with audiovisual cues. This may provide evidence for children’s less developed higher-level cognitive strategies in dealing with speech-in-noise (e.g., selective attention). Findings from the second analysis suggest that despite two competing lexicons, simultaneous bilinguals do not experience a speech perception-in-noise deficit relative to monolinguals.
Experience-independent effects of matching and non-matching visual information on speech perception
Authors: Danielson D. Kyle , Greuel Alison J. , Kandhadai Padmapriya , Werker Janet F.
Published: October 2014

Infants are sensitive to the correspondence between visual and auditory speech. Infants exhibit the McGurk effect, and matching audiovisual information may facilitate discrimination of similar consonant sounds in an infant’s native language (e.g., Teinonen et al., 2008). However, because most existing research in audiovisual speech perception has been conducted using native speech sounds with infants in their first year of life, little work has explored whether this link between the auditory and visual modalities of speech perception arises due to experience with the native language. In the present set of studies, English-learning six- and ten-month-old infants are tested for discrimination of a non-English speech contrast following familiarization with matching and mismatching audiovisual speech. Furthermore, the looking fixation behaviors of the two age groups are compared between the two conditions. Although it has been demonstrated that infants in the younger age range attend preferentially to the eye region when viewing matched audiovisual speech and that infants in the older age range temporarily attend to the mouth region (Lewkowicz & Hansen-Tift, 2012), here deviations in this behavior for matching and mismatching non-native speech are examined (a link that has only been previously explored in the native language (Tomalski et al., 2013)).
Switched-dominance bilingual speech production: Continuous usage versus early exposure
Authors: Blasingame Michael , Bradlow Ann R.
Published: October 2014

Switched dominance bilinguals (i.e., “heritage speakers,” HS, with L2 rather than L1 dominance) have exhibited native-like heritage language (L1) sound perception (e.g., Korean three-way VOT contrast discrimination by Korean HS; Oh, Jun, Knightly, & Au, 2003) and sound production (e.g., Spanish VOT productions by Spanish HS; Au, Knightly, Jun, & Oh, 2002), but far from native-like proficiency in other aspects of L1 function, including morphosyntax (Montrul, 2010). We investigated whether native-like L1 sound production proficiency extended to heritage language sentence-in-noise intelligibility. We recorded English and Spanish sentences by Spanish HS (SHS) and monolingual English controls (English only). Native listeners of each language transcribed these recordings under easy (-4 dB SNR) and hard (-8 dB SNR) conditions. In easy conditions, SHS English and Spanish intelligibility were not significantly different, yet in hard conditions, SHS English intelligibility was significantly higher than SHS Spanish intelligibility. Furthermore, we observed no differences between SHS English and English-control intelligibility in both conditions. These results suggest for SHS, while early Spanish exposure provided some resistance to heritage language/L1 intelligibility degradation, the absence of continuous Spanish usage impacted intelligibility in severely degraded conditions. In contrast, the absence of early English exposure was entirely overcome by later English dominance.
Inaudible information, disappearing declamations, misattributed locations, and other spooky ways your brain fools you—every day
Authors: Shinn-Cunningham Barbara
Published: October 2014

We bumble through life convinced that our senses provide reliable, faithful information about the world. Yet on closer inspection, our brains constantly misinform us, creepily convincing us of “truths” that are just plain false. We hear information that is not really there. We are oblivious to sounds that are perfectly audible. For sounds that we do hear, we cannot tell when they actually occurred. We completely overlook changes that even a simple acoustic analysis would detect with 100% accuracy. In short, we misinterpret the sounds reaching our ears all the time, and do not even realize it. This talk will review the evidence for how unreliable and biased we are in interpreting the world—and why the chilling failures of our perceptual machinery may be excusable, or even useful, as we navigate the complex world in which we live.
Large-scale passive-acoustics-based population estimation of African forest elephants
Authors: Shiu Yu , Keen Sara , Wrege Peter H. , Rowland Elizabeth
Published: October 2014

African forest elephants (Loxodonta cyclotis) live in tropical rainforests in Central Africa and often use low-frequency vocalizations for long-distance communication and coordination of group activities. There is great interest in monitoring population size in this species; however, the dense rainforest canopy severely limits visibility, making it difficult to estimate abundance using traditional methods such as aerial surveys. Passive acoustic monitoring offers an alternative approach of estimating its abundance in a low visibility environment. The work we present here can be divided into three steps. First, we apply an automatic elephant call detector, which enables the processing of large-scale acoustic signals in a reasonable amount of time. Second, we apply a density estimation method we designed for a single microphone. Because microphones are often positioned far apart in order to cover a large area in the rainforest, meaning that the same call will not produce multiple arrivals on different recording units. Lastly, we examine results from our historic data across five years in six locations in central Africa, which includes over 1000 days of sound stream. We will address the feasibility of long-term population monitoring and also the potential impact of human activity on elephant calling behavior.
An experimental evaluation of the performance of acoustic recording systems for estimating avian species richness and abundance
Authors: Celis Murillo Antonio , Deppe Jill , Riddle Jason , Ward Michael P. , Simons Theodore
Published: October 2014

Comparisons between field observers and acoustic recording systems have shown great promise for sampling birds using acoustics methods. Comparisons provide information about the performance of recording systems and field observers but do not provide a robust validation of their true sampling performance—i.e., precision and accuracy relative to known population size and richness. We used a 35-speaker bird song simulation system to experimentally test the accuracy and precision of two stereo (Telinga and SS1) and one quadraphonic recording system (SRS) for estimating species richness, abundance, and total abundance (across all species) of vocalizing birds. We simulated 25 bird communities under natural field conditions by placing speakers in a wooded area at 4–119 m from the center of the survey at differing heights and orientations. We assigned recordings randomly to one of eight skilled observers. We found a significant difference among microphones in their ability to accurately estimate richness (p = 0.0019) and total bird abundance (p = < 0.0001). Our study demonstrates that acoustic recording systems can potentially estimate bird abundance and species richness accurately; however, their performance is likely to vary by its technical characteristics (recording pattern, microphone arrangement, etc.).
Preliminary calculation of individual echolocation signal emission rate of Franciscana dolphins (Pontoporia blainvillei)
Authors: Andriolo Artur , Sucunza Federico , Zerbini Alexandre N. , Danilewicz Daniel , Cremer Marta J. , Holz Annelise C.
Published: October 2014

Calculation of echolocation signals emission rate is necessary to estimate how many individuals are vocalizing, especially if passive acoustic density estimation methods are to be implemented. We calculated the individual emission rate of echolocation signals of franciscana dolphin. Fieldwork was between 22 and 31 January of 2014 at Babitonga Bay, Brazil. Acoustic data and group size were registered when animals were within visual range at maximum distance of 50 meters. We used a Cetacean Research™ hydrophone. The sound was digitized by Analogic/Digital IOtech, stored as wav-files and analyzed with Raven software. A band limited energy detector was set to automatically extract echolocation signals. The emission rate was calculated dividing the clicks registered for each file by the file duration and by the number of individuals in the group. We analyzed 240 min of sound of 36 groups. A total of 29,164 clicks were detected. The median individual click rate was 0.290 clicks/s (10th = 0.036 and 90th = 1.166 percentiles). The result is a general approximation of the individual echolocation signal emission rate. Sound production rates are potentially dependent on a number of factors, like season, group size, sex, or even density itself. [This study was supported by IWC/Australia, Petrobras, Fundo de Apoio à Pesquisa/UNIVILLE.]
Destruction of microorganisms by high-energy pulsed focused ultrasound
Authors: Bigelow Timothy A.
Published: October 2014

The use of high-energy ultrasound pulses to generate and excite clouds of microbubbles has shown great potential to mechanically destroy soft tissue in a wide range of clinical applications. In our work, we have focused on extending the application of cavitation based histotripsy to the destruction of microorganisms such as bacteria biofilms and microalgae. Bacteria biofilms pose a significant problem when treating infections on medical implants while the fractionation of microalgae in an efficient manner could lower the production cost of biofuels. In the past, we have shown a 4.4-log10 reduction of viable Escherichia coli bacteria capable of forming a colony in a biofilm following a high-energy pulsed focused ultrasound exposure. We have also shown complete removal of Pseudomonas aeruginosa biofilms from a Pyrolytic graphite substrate based on fluorescence imaging following live/dead staining. We also showed minimal temperature increase when the appropriate ultrasound pulse parameters were utilized. Recently, we have shown that high-energy pulsed ultrasound at 1.1 MHz can fractionate the microalgae model system Chlamydomonas reinhardtii for lipid extraction/biofuel production in both flow and stationary exposure systems with improved efficiency over traditional sonicators. In these studies, the fractionation of the cells was quantified by protein and chlorophyll release following exposure.
Dependence of ablative ability of high-intensity focused ultrasound cavitation-based histotripsy on mechanical properties of agar
Authors: Xu Jin , Bigelow Timothy , Davis Gabriel , Avendano Alex , Shrotriya Pranav , Bergler Kevin , Hu Zhong
Published: October 2014

Cavitation-based histotripsy uses high-intensity focused ultrasound (HIFU) at low duty factor to create bubble clouds inside tissue to liquefy a region and provides better fidelity to planned lesion coordinates and the ability to perform real-time monitoring. The goal of this study was to identify the most important mechanical properties for predicting lesion dimensions, among these three: Young's modulus, bending strength, and fracture toughness. Lesions were generated inside tissue-mimicking agar, and correlations were examined between the mechanical properties and the lesion dimensions, quantified by lesion volume and by the width and length of the equivalent bubble cluster. Histotripsy was applied to agar samples with varied properties. A cuboid of 4.5 mm width (lateral to focal plane) and 6 mm depth (along beam axis) was scanned in a raster pattern with respective step sizes of 0.75 mm and 3 mm. The exposure at each treatment location was 15 s, 30 s, or 60 s long. Results showed that only Young's modulus influenced histotripsy's ablative ability and was significantly correlated with lesion volume and bubble cluster dimensions. The other two properties had negligible effects on lesion formation. Also, exposure time differentially affected the width and depth of the bubble cluster volume.
Ultrasound-induced fractionation of the intervertebral disk
Authors: Elbes Delphine , Boubriak Olga , Qiao Shan , Molinari Michael , Urban Jocelyn , Cleveland Robin , Coussios Constantin
Published: October 2014

Current surgical treatments for lower back pain, which is strongly associated with degeneration of the intervertebral disk, are highly invasive and have low long-term success rates. The present work thus aims to develop a novel, minimally invasive therapy for disk replacement without the need for surgical incision. Using ex vivo bovine coccygeal spinal segments as an experimental model, two confocally aligned 0.5 MHz HIFU transducers were positioned with their focus inside the disc and used to generate peak rarefactional pressures in the range of 1–12 MPa. Cavitation activity was monitored, characterized, and localized in real time using both a single-element passive cavitation detector and a 2D Passive Acoustic Mapping array. The inertial cavitation threshold in the central portion of the disk, the nucleus pulposus (NP), was first determined both in the absence and in the presence of externally injected cavitation nuclei. HIFU exposure parameters were subsequently optimized to maximize sustained inertial cavitation over 10 min and achieve fractionation of the NP. Following sectioning of treated disks, staining of live and dead cells as well as microscopy under polarized light were used to assess the impact of the treatment on cell viability and collagen structure within the NP, inner annulus and outer annulus.
Reverberation models as an aid to interpret data and extract environmental information
Authors: Ellis Dale D. , Preston John R.
Published: October 2014

Reverberation measurements obtained with towed arrays are a valuable tool to extract information about the ocean environment. Preston pioneered the use of polar plots to display reverberation and superimpose the beam time series on bathymetry maps. As part of Rapid Environmental Assessment (REA) exercises Ellis and Preston [J. Marine Syst. 78, S359–S371, S372–S381] have used directional reverberation measurements to detect uncharted bottom features, and to extract environmental information using model-data comparisons. One enthusiast declared “This is like doing 100 simultaneous transmission loss runs and having the results available immediately.” Though that was clearly an exaggeration and the results are not precise, the approach provides valuable information to direct more accurate and detailed surveys. The early work used range-independent (flat bottom) models for the model-data comparisons, while current work includes a range-dependent model based on adiabatic normal modes. A model has been developed which calculates reverberation from range-dependent bottom bathymetry, echoes from targets and discrete clutter objects, then outputs beam time series directly comparable with measured ones. Recent work has identified interesting effects in sea bottom sand dunes in the TREX experiments. This paper will provide an overview of the earlier work, and examples from the recent TREX experiment.
A new dual-task paradigm to assess cognitive resources utilized during speech recognition
Authors: Plotkowski Andrea R. , Alexander Joshua M.
Published: October 2014

Listening to ongoing conversations in challenging situations requires explicit use of cognitive resources to decode and process spoken messages. Traditional speech recognition tests are insensitive measures of this cognitive effort, which may differ greatly between individuals or listening conditions. Furthermore, most dual-task paradigms that have been devised for this purpose generally rely on secondary tasks like reaction time and recall that do not reflect real-world listening demands. A new task was designed to capture changes in both speech recognition and verbal processing across different conditions. Listeners heard two sequential sentences spoken by opposite gender talkers in speech-shaped noise. The primary task was a traditional speech recognition test, in which listeners immediately repeated aloud the second sentence in the pair. The secondary task was designed to engage explicit cognitive processes by requiring listeners to write down the first sentence after holding it in memory while listening to and repeating back the second sentence. Test sentences consisted of lists from the PRESTO test (Gilbert et al. 2013, J. Am. Acad. Audiol. vol. 24, pp. 26–36) that were carefully modified to help ensure list-equivalency. Psychometric results from the revised PRESTO sentence lists and from the new dual-sentence task will be reported.
The gradient effect of transitional magnitude: A source of the vowel context effect
Authors: LEE-KIM SANG-IM
Published: October 2014

Previous studies have shown that vocalic transitions play an important role in the identification of the consonantal places (e.g., Whalen 1981/1991, Nowak 2006, Babel & McGuire 2013). While it has been intermittantly reported that the contribution of transitions may depend on vowel contexts, the common methodology, i.e., C-V cross-splicing, is too coarse to precisely identify the nature of this effect. In the present study, vocalic transitions are systematically manipulated and used as a gradient variable by incrementally removing the transitional period of the three vowels /u a e/ following alveolopalatal sibilant /ɕ/ in Polish. In an identification task, native Polish speakers were given a choice between /ɕ/ and /ʂ/ for stimuli with varying levels of palatal transitions. The results showed that participants’ perception is gradient: greater transitions overall elicit more palatal responses in all vowel contexts. More importantly, it has been shown that the apparent vowel effect can be largely reduced to the relative magnitude of transitions that are specific to each vowel. The low and back vowels elicit greater palatal transitions providing more robust transitional cues in perception, while the high and front vowels elicit smaller or nearly zero palatal transitions providing less robust cues to the sibilants’ place.
Adaptive compensation for reliable spectral characteristics of a listening context in vowel perception
Authors: Anderson Paul , Stilp Christian
Published: October 2014

When precursor sounds are filtered to emphasize frequencies matching F2 of a subsequent target vowel, vowel perception decreases reliance on F2 (predictable cue) and increases reliance on spectral tilt (unpredictable cue) and vice versa. Previously, initial cue weights and weight changes (i.e., perceptual calibration to reliable signal properties) were larger for F2 than tilt, obscuring whether the magnitude of calibration reflects cue predictability or F2’s status as a primary cue to vowel identity. Here, vowels varied from /u/ to /i/ in tilt (-12-0 dB/octave) and the full range of F2 values (1000–2200 Hz) or a reduced range (1300–1900 Hz) designed to decrease F2 cue weights, making tilt the primary cue for vowel identification. Vowels were presented in isolation, then following sentences filtered to match the target vowel’s F2 or tilt. In isolation, cue weights for F2 were higher when identifying full-F2-range vowels and higher for tilt when identifying reduced-F2-range vowels. Weight changes (calibration) were comparable when the primary cue was predictable; this was also true for predictable secondary cues (tilt for full-F2-range vowels, F2 for reduced-F2-range vowels). Perceptual calibration to reliable signal properties is an adaptive process reflecting cue predictability, not solely a priori cue use (e.g., F2 over tilt).
Vowel development in children with Down and Williams syndromes
Authors: Jacewicz Ewa , Fox Robert A. , Stojanovik Vesna , Setter Jane
Published: October 2014

Down syndrome (DS) and Williams syndrome (WS) are genetic disorders resulting from different types of genetic errors. While both disorders lead to phonological and speech motor deficits, particularly little is known about vowel production in DS and WS. Recent work suggests that impaired vowel articulation in DS likely contributes to the poor intelligibility of DS speech. Developmental delays in temporal vowel structure and pitch control have been found in children with WS when compared to their chronological matches. Here, we analyze spontaneous speech samples produced by British children with DS and WI and compare them with typically developing children from the same geographic area in Southern England. We focus on the acquisition of fine-grained phonetic details, asking if children with DS and WS are able to synchronize the phonetic and indexical domains while coping with articulatory challenges related to their respective syndromes. Phonetic details pertaining to the spectral (vowel-inherent spectral change) and indexical (regional dialect) vowel features are examined and vowel spaces are derived from formant values sampled at multiple temporal locations. Variations in density patterns across the vowel space are also considered to define the nature of the acoustic overlap in vowels related to each syndrome.
Speech production changes and intelligibility with a real-time cochlear implant simulator
Authors: Talesnick Lily , Casserly Elizabeth D.
Published: October 2014

Subjects hearing their speech through a real-time cochlear implant (CI) simulator alter their production in multiple ways, e.g., reducing speaking rate and constricting F1/F2 vowel space. The motivations behind these alterations, however, are currently unknown. Two possibilities are that the changes in speech are due to the influence of a direct feedback loop in which the subject is adjusting speech production to minimize acoustic “error,” or that the changes could reflect the indirect influence of a high cognitive load (stemming from the challenge of hearing through the real-time CI simulator). We explored these two possibilities by conducting a playback experiment in which 35 naïve listeners assessed the intelligibility of speech produced under conditions of normal versus vocoded feedback. Intelligibility of vocoded isolated word stimuli in each condition was tested in both a two-alternative forced choice task (“Which recording is easier to understand?”) and an open-set word recognition task. Listeners found normal-feedback speech significantly more intelligible in both tasks (p’s < 0.0125), suggesting that speakers were not adjusting for direct error correction, but rather due to the influence of an intervening factor, e.g., high cognitive load. Confusion matrix analyses further illuminate the perceptual consequences of the effects of CI-simulated speech feedback.
Thai phonetically balanced word recognition test: Reliability evaluations and bias and error analysis
Authors: Munthuli Adirek , Onsuwan Chutamanee , Tantibundhit Charturong , Kosawat Krit
Published: October 2014

Word recognition score (WRS) is one of the measuring techniques used in speech audiometry, a part of a routine audiological examination. The test’s accuracy is crucial and largely depends on the test materials. With emphasis on phonetic balance, test-retest reliability, inter-list equivalency, and symmetrical phoneme occurrence, Thammasat University Phonetically Balanced Word Lists 2014 (TU PB’14) were created with five different lists, each with 25 Thai monosyllabic words. TU PB’14 reflects Thai phoneme distribution based on large-scale written Thai corpora, InterBEST [1]. To evaluate its validity and test-retest reliability, the lists were given at five intensity levels (15–55 dB HL) in test and retest sessions to 30 normal-hearing subjects. The differences in performance between the two sessions are not significantly large and correlation coefficients at the linear regions are all positive. Analysis of listeners’ errors, including sequence recurrences, was carried out. Errors occurred predominantly in the case of initials, followed by finals and lexical tones. Confusion patterns of initials, finals, and tones are in line with those found for Thai speech sounds in noise condition. Interestingly, vowels are found to be most resistant to confusion. Finally, possible effect of lexical frequency is examined and discussed.
Talker variability in spoken word recognition: Evidence from repetition priming
Authors: Zhang Yu , Lee Chao-Yang
Published: October 2014

The effect of talker variability on the processing of spoken words is investigated using short-term repetition priming experiments. Prime-target pairs, either repeated (e.g., queen-queen) or unrelated (e.g., bell-queen), were produced by the same or different male speakers. Two interstimulus intervals (ISI, 50 and 250 ms) were used to explore the time course of repetition priming and voice specificity effects. The auditory stimuli were presented to 40 listeners, who completed a lexical decision task followed by a talker voice discrimination task. Results from the lexical decision task showed that the magnitude of priming was attenuated in the different-talker condition, indicating a talker variability effect on spoken word recognition. In contrast, the talker variability effect on priming did not differ between the two ISIs. Talker voice discrimination was faster and more accurate for nonword targets, but not for word targets, indicating a lexical status effect on voice discrimination. Taken together, these results suggest that talker variability affects recognition of spoken words, and that the effect cannot be simply attributed to non-lexical voice discrimination.
What do we know and what do we need to know about submarine canyons for acoustics?
Authors: Lynch James , Lin Ying-Tsong , Duda Timothy , Newhall Arthur , Gawarkiewicz Glen
Published: October 2014

Acoustic propagation and scattering in marine canyons is an inherently 3-D problem, both for the environmental input (bottom topography and geology, biology, and physical oceanography) and the acoustic field. In this talk, we broadly examine what our knowledge is of these environmental fields, and what their salient effects should be upon acoustics. Examples from recent experiments off the United States and Taiwan will be presented, along with other historical data. Three dimensional acoustic modeling results will also be presented. Directions for future research will be discussed.
Fiery ice from the sea: Marine gas hydrates
Authors: Chapman Ross
Published: October 2014

Marine gas hydrates are cage-like structures of water containing methane or some higher hydrocarbons that are stable under conditions of high pressures and low temperatures. The hydrate structures are formed in sediments of continental margins and are found worldwide. The stability zone extends to about 200 m beneath the sea floor, and hydrates exist in several different forms within the zone, from massive ice-like features at cold seeps on the sea floor to finely distributed deposits in sediment pores over extensive areas. The base of the stability zone is characterized by a strong acoustic impedance change from high velocity hydrated sediments above to low velocity gas below. This acoustic feature generates a strong signal in seismic surveys called the Bottom Simulating Reflector, and it is widely used as an indicator of the presence of hydrates. This paper reviews the current knowledge of hydrate systems from research carried out on the Cascadia Margin off the west coast of Vancouver Island, and in the Gulf of Mexico. The hydrate distributions are different in each of these areas, leading to different effects in acoustic reflectivity.
Three dimensional underwater acoustic modeling on continental slopes and submarine canyons
Authors: Lin Ying-Tsong , Barclay David , Duda Timothy F. , Zhang Weifeng Gordon
Published: October 2014

Underwater sound propagation on slopes and canyons is influenced jointly and strongly by the complexity of topographic variability and ocean dynamics. Some integrated ocean and acoustic models have been developed and implemented to investigate such joint acoustic effects. In this talk, an integrated numerical model employing a time-stepping three-dimensional (3D) parabolic-equation (PE) acoustic modeling method and the Regional Ocean Modeling System (ROMS) is presented. Numerical examples of sound propagation and ambient noise in Mid-Atlantic Bight area with realistic environmental conditions are demonstrated. The sound propagation model reveals the focusing of sound due to concave canyon seafloor and the different level of temporal variability of focused and unfocused sound. The ambient noise model is constructed for surface wind generated noise, and the model shows the azimuthal dependency of noise field and its spatial coherence structure. Lastly, a simple sonar performance prediction is made to investigate the variability of the probability of detection in these complex underwater environments. [Work supported by the ONR.]
Three-dimensional effects in the sound propagation in area of coastal slope
Authors: Katsnelson Boris , Malykhin Andrey
Published: October 2014

Coastal slope (wedge) in the ocean is well known “canonical” problem for analysis of manifestation of the horizontal refraction (3d effects) in a shelf zone. In given paper the following effects are reviewed:(1) Spatial variability of the sound field in given area. Areas of one-path and multipath propagation, shadow zones, and caustics in horizontal plane, their properties in dependence on the frequency, influence of bottom parameters;(2) Interference structure of the sound field in the horizontal plane in dependence on mode number and frequency;(3) Distribution of the sound field in vicinity of curvilinear coastal line, for example, gulf, bay, peninsula etc. (shadow zones, multipath area, and whispering gallery waveguide in horizontal plane);(4) Temporal variability of signals due to frequency dependence of the horizontal refraction and in turn pulse compression/decompression and time reversal in multipath area;(5) time-frequency diagrams; Mentioned and other effects can change properties of bottom and surface reverberation, scattering, noise field distribution, attenuation in area of coastal wedge. The corresponding estimations are presented. [Work was supported by BSF, Grant 2010471, RFBR-NSFC Grant 14-05-91180.]
Reporting Physical Activity: Perceptions and Practices of Australian Media Professionals
Authors: Smith Ben J. , Bonfiglioli Catriona M.F.
Published: October 2014

Background:

Advocacy informed by scientific evidence is necessary to influence policy and planning to address physical inactivity. The mass media is a key arena for this advocacy. This study investigated the perceptions and practices of news media professionals reporting physical activity and sedentariness to inform strategic communication about these issues.

Methods:

We interviewed media professionals working for major television, radio, newspaper and online news outlets in Australia. The interviews explored understandings of physical activity and sedentariness, attributions of causality, assignment of responsibility, and factors affecting news reporting on these topics. Data were thematically analyzed using NVivo.

Results:

Physical inactivity was recognized as pervasive and important, but tended to be seen as mundane and not newsworthy. Sedentariness was regarded as more novel than physical activity, and more likely to require organizational and environment action. Respondents identified that presenting these issues in visual and engaging ways was an ongoing challenge.

Conclusions:

Physical activity researchers and advocates need to take account of prevailing news values and media practices to improve engagement with the news media. These include understanding the importance of novelty, narratives, imagery, and practical messages, and how to use these to build support for environmental and policy action.
Activity Behaviors of University Staff in the Workplace: A Pilot Study
Authors: Bird Marie-Louise , Shing Cecilia , Mainsbridge Casey , Cooley Dean , Pedersen Scott
Published: October 2014

Background:

Sedentary behavior is related to metabolic syndrome and might have implications for the long-term health of workers in a low activity environment. The primary aim of this pilot study was to determine activity levels of adults working at a University during work hours. A secondary aim was to determine the relationship between actual and perceived activity levels.

Methods:

Activity levels of university staff (n = 15, male = 7, age = 53 ± 7 years, BMI = 26.5 ± 2.5kg·m2) were monitored over 5 consecutive workdays using SenseWear accelerometers, then participants completed a questionnaire of their perception of workplace sedentary time.

Results:

Each participant spent 71.5 ± 13.1% (358 ± 78 min) of their workday being sedentary (< 1.5 METs), 15.6 ± 9.0% involved in light activity (1.5–3 METs), 11.7 ± 10.0% in moderate activity (3–5 METs), and 1.1 ± 1.3% in vigorous activity (> 5 METs) (P < .0001). The mean difference between actual (SenseWear < 1.5 METs) and perceived sitting time was –2 ± 32%; however, perceived sedentary time was reported with a range of under-to-over estimation of –75% to 51%.

Conclusion:

This pilot study identifies long periods of low metabolic activity during the workday and poor perception of individual sedentary time. Interventions to reduce sedentary time in the workplace may be necessary to ensure that the work environment does not adversely affect long-term health.
Postprandial Metabolic Effects of Accelerometer Measured Spontaneous Low-Level Activity
Authors: Peddie Meredith C. , Cameron Claire , Rehrer Nancy , Perry Tracy
Published: October 2014

Background:

Interrupting sedentary time induces improvements in glucose metabolism; however, it is unclear how much activity is required to reduce the negative effects of prolonged sitting.

Methods:

Sixty-six participants sat continuously for 9 hours except for required bathroom breaks. Participants were fed meal replacement beverages at 60, 240 and 420 min. Blood samples were obtained hourly for 9 hours, with additional samples collected 30 and 45 min after each feeding. Responses were calculated as incremental area under the curve (iAUC) for plasma glucose, insulin and triglyceride. Participants wore a triaxial accelerometer and a heart rate monitor. Energy expenditure was estimated using indirect calorimetry.

Results:

After controlling for age, sex and BMI, every 100 count increase in accelerometer derived total movement was associated with a 0.06 mmol·L-1·9 hours decrease in glucose iAUC (95% CI 0.004–0.1; P = .035), but not associated with changes in insulin or triglyceride iAUC. Every 1 bpm increase in mean heart rate was associated with a 0.76 mmol·L-1·9 hours increase in triglyceride iAUC (95% CI 0.13–1.38).

Conclusion:

Accelerometer measured movement during periods of prolonged sitting can result in minor improvements in postprandial glucose metabolism, but not lipid metabolism.
An
In Planta
-Expressed Polyketide Synthase Produces (
R
)-Mellein in the Wheat Pathogen Parastagonospora nodorum
Authors: Chooi Yit-Heng , Krill Christian , Barrow Russell A. , Chen Shasha , Trengove Robert , Oliver Richard P. , Solomon Peter S.
Published: October 2014

Parastagonospora nodorum
is a pathogen of wheat that affects yields globally. Previous transcriptional analysis identified a partially reducing polyketide synthase (PR-PKS) gene, SNOG_00477 (
SN477
), in
P. nodorum
that is highly upregulated during infection of wheat leaves. Disruption of the corresponding
SN477
gene resulted in the loss of production of two compounds, which we identified as (
R
)-mellein and (
R
)-
O
-methylmellein. Using a
Saccharomyces cerevisiae
yeast heterologous expression system, we successfully demonstrated that SN477 is the only enzyme required for the production of (
R
)-mellein. This is the first identification of a fungal PKS that is responsible for the synthesis of (
R
)-mellein. The
P. nodorum
Δ
SN477
mutant did not show any significant difference from the wild-type strain in its virulence against wheat. However, (
R
)-mellein at 200 μg/ml inhibited the germination of wheat (
Triticum aestivum
) and barrel medic (
Medicago truncatula
) seeds. Comparative sequence analysis identified the presence of mellein synthase (MLNS) homologues in several Dothideomycetes and two sodariomycete genera. Phylogenetic analysis suggests that the MLNSs in fungi and bacteria evolved convergently from fungal and bacterial 6-methylsalicylic acid synthases.
Enhancing Terpene Yield from Sugars via Novel Routes to 1-Deoxy-
d
-Xylulose 5-Phosphate
Authors: Kirby James , Nishimoto Minobu , Chow Ruthie W. N. , Baidoo Edward E. K. , Wang George , Martin Joel , Schackwitz Wendy , Chan Rossana , Fortman Jeffrey L. , Keasling Jay D.
Published: October 2014

Terpene synthesis in the majority of bacterial species, together with plant plastids, takes place via the 1-deoxy-
d
-xylulose 5-phosphate (DXP) pathway. The first step of this pathway involves the condensation of pyruvate and glyceraldehyde 3-phosphate by DXP synthase (Dxs), with one-sixth of the carbon lost as CO
2
. A hypothetical novel route from a pentose phosphate to DXP (nDXP) could enable a more direct pathway from C
5
sugars to terpenes and also circumvent regulatory mechanisms that control Dxs, but there is no enzyme known that can convert a sugar into its 1-deoxy equivalent. Employing a selection for complementation of a
dxs
deletion in
Escherichia coli
grown on xylose as the sole carbon source, we uncovered two candidate nDXP genes. Complementation was achieved either via overexpression of the wild-type
E. coli
yajO
gene, annotated as a putative xylose reductase, or via various mutations in the native
ribB
gene.
In vitro
analysis performed with purified YajO and mutant RibB proteins revealed that DXP was synthesized in both cases from ribulose 5-phosphate (Ru5P). We demonstrate the utility of these genes for microbial terpene biosynthesis by engineering the DXP pathway in
E. coli
for production of the sesquiterpene bisabolene, a candidate biodiesel. To further improve flux into the pathway from Ru5P, nDXP enzymes were expressed as fusions to DXP reductase (Dxr), the second enzyme in the DXP pathway. Expression of a Dxr-RibB(G108S) fusion improved bisabolene titers more than 4-fold and alleviated accumulation of intracellular DXP.
A rare cause of hypoactive delirium
Authors: Kosari S A , Amiruddin A , Shorakae S , Kane R
Published: October 2014

A 90-year-old man was transferred to a geriatric evaluation and management (GEM) unit for management of hypoactive delirium following a pneumonia and acute myocardial infarction complicated by septic shock. He was found to have central hypothyroidism and hypoadrenalism leading to the diagnosis of hypopituitarism. Cerebral imaging confirmed this was secondary to a pituitary haemorrhage. This case illustrates the complexity of assessment of delirium and its aetiologies. Hypoactive forms of delirium in particular can be difficult to detect and therefore remain undiagnosed. While this patient's delirium was likely multifactorial, his hypopituitary state explained much of his hypoactivity. His drowsiness, bradycardia, hypotension and electrolyte imbalance provided clinical clues to the diagnosis.
Management of an unusual case of iatrogenic parotid sialocele using an infant feeding tube: a novel approach
Authors: Kulkarni Ambadas , Chandrasala Soumithran , Nimbeni Basavaraj S , Pal Singh Surendar , Golai Shruti
Published: October 2014

Injuries to the parotid duct and parenchyma resulting in swelling in the cheek region commonly present in maxillofacial practice. Sialocele is a discrete collection of saliva in a subcutaneous cavity that can be iatrogenic, idiopathic or the result of post-traumatic injuries to the duct or parenchyma, presenting as a salivary pseudocyst or retention cyst. We present an unusual case of parotid sialocele following surgery for sialolithiasis which presented with progressive painless swelling in the preauricular region of 9 months duration. Treatment included surgical exploration under local anaesthesia and draining the cavity by keeping the opening patent using an infant feeding tube.