bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute cardiopulmonary toxicity of inhaled aldehydes: role of TRPA1
Authors: Conklin Daniel J.
Published: May 2016

Inhalation of high‐level volatile aldehydes, as present in smoke from wildfires and in tobacco smoke, is associated with both acute and chronic cardiopulmonary morbidity and mortality, but the underlying mechanisms are unclear. The transient receptor potential ankyrin 1 (TRPA1) protein forms a cation channel (irritant receptor) that mediates tobacco smoke–induced airway and lung injury, yet the role of TRPA1 in the cardiovascular toxicity of aldehyde exposure is unclear. Physiologically, airway‐located TRPA1 activation triggers an irritant response (e.g., coughing and “respiratory braking”) that alters the rate and depth of breathing to reduce exposure. Acrolein (2‐propenal), a volatile, unsaturated aldehyde, activates TRPA1. Acrolein was used as a chemical weapon in World War I and is present at high levels in wildfires and tobacco smoke. Acrolein is thought to contribute to pulmonary and cardiovascular injury caused by tobacco smoke exposure, although the role of TRPA1 in cardiovascular toxicity is unclear. This minireview addresses this gap in our knowledge by exploring literature and recent data indicating a connection between TRPA1 and cardiovascular as well as pulmonary injury due to inhaled aldehydes.
Filifactor alocis collagenase can modulate apoptosis of normal oral keratinocytes
Authors: Chioma O. , Aruni A.W. , Milford T.‐A. , Fletcher H.M.
Published: May 2016

To successfully colonize host cells, pathogenic bacteria must circumvent the host's structural barrier such as the collagen‐rich extracellular matrix (ECM), as a preliminary step to invasion and colonization of the periodontal tissue. Filifactor alocis possesses a putative Peptidase U32 family protein (HMPREF0389_00504) with collagenase activity that may play a significant role in colonization of host tissue during periodontitis by breaking down collagen into peptides and disruption of the host cell. Domain architecture of the HMPREF0389_00504 protein predicted the presence of a characteristic PrtC‐like collagenase domain, and a peptidase domain. Our study demonstrated that the recombinant F. alocis peptidase U32 protein (designated PrtFAC) can interact with, and degrade, type I collagen, heat‐denatured collagen and gelatin in a calcium‐dependent manner. PrtFAC decreased viability and induced apoptosis of normal oral keratinocytes (NOKs) in a time and dose‐dependent manner. Transcriptome analysis of NOK cells treated with PrtFAC showed an upregulation of the genes encoding human pro‐apoptotic proteins: Apoptotic peptidase activating factor 1 (Apaf1) cytochrome C, as well as caspase 3 and caspase 9, suggesting the involvement of the mitochondrial apoptotic pathway. There was a significant increase in caspase 3/7 activity in NOK cells treated with PrtFAC. Taken together, these findings suggest that F. alocis PrtFAC protein may play a role in the virulence and pathogenesis of F. alocis.
Physics and Causation
Authors: Blanchard Thomas
Published: May 2016

More than a century ago, Russell launched a forceful attack on causation, arguing not only that modern physics has no need for causal notions but also that our belief in causation is a relic of a pre‐scientific view of the world. He thereby initiated a debate about the relations between physics and causation that remains very much alive today. While virtually everybody nowadays rejects Russell's causal eliminativism, many philosophers (although by no means all) have been convinced by Russell that the fundamental physical structure of our world doesn't contain causal relations. This raises the question of how to reconcile the central role of causal concepts in the special sciences and in common sense with the putative absence of causation in fundamental physics.
Quantifying learning‐dependent changes in the brain: Single‐trial multivoxel pattern analysis requires slow event‐related fMRI
Authors: Visser Renée M. , de Haan Michelle I. C. , Beemsterboer Tinka , Haver Pia , Kindt Merel , Scholte H. Steven
Published: May 2016

Single‐trial analysis is particularly useful for assessing cognitive processes that are intrinsically dynamic, such as learning. Studying these processes with fMRI is problematic, as the low signal‐to‐noise ratio of fMRI requires the averaging over multiple trials, obscuring trial‐by‐trial changes in neural activation. The superior sensitivity of multivoxel pattern analysis over univariate analyses has opened up new possibilities for single‐trial analysis, but this may require different fMRI designs. Here, we measured fMRI and pupil dilation responses during discriminant aversive conditioning, to assess associative learning in a trial‐by‐trial manner. The impact of design choices was examined by varying trial spacing and trial order in a series of five experiments (total n = 66), while keeping stimulus duration constant (4.5 s). Our outcome measure was the change in similarity between neural response patterns related to two consecutive presentations of the same stimulus (within‐stimulus) and between patterns related to pairs of different stimuli (between‐stimulus) that shared a specific outcome (electric stimulation vs. no consequence). This trial‐by‐trial similarity analysis revealed clear single‐trial learning curves in conditions with intermediate (8.1–12.6 s) and long (16.5–18.4 s) intervals, with effects being strongest in designs with long intervals and counterbalanced stimulus presentation. No learning curves were observed in designs with shorter intervals (1.6–6.1 s), indicating that rapid event‐related designs—at present, the most common designs in fMRI research—are not suited for single‐trial pattern analysis. These findings emphasize the importance of deciding on the type of analysis prior to data collection.
When the poor excel: Poverty facilitates procedural learning
Authors: Dang Junhua , Xiao Shanshan , Zhang Ting , Liu Ying , Jiang Bin , Mao Lihua
Published: May 2016

Recent research has shown that poverty directly impeded cognitive functions because the poor could be easily distracted by monetary concerns. We argue that this effect may be limited to functions relying on working memory. For functions that rely on proceduralized processes however, monetary concerns elicited by reminding of financial demands would be conducive rather than harmful. Our results supported this hypothesis by showing that participants with lower income reached the learning criterion of the information‐integration categorization task faster than their more affluent counterparts after reminding of financial demands.
A new HLA‐B allele, B*52:44, sequenced in a Chinese individual
Authors: Wang X. , Wang J. , Zhang Y. , Li Q. , Ru K.
Published: May 2016

One nucleotide replacement in codon 154 (GAG>GAT) of HLA‐B*52:01:01:01 results in a novel allele formation, HLA‐B*52:44.
Africa's passive revolution: crisis in Malawi
Authors: Brooks Andrew , Loftus Alex
Published: May 2016

Recent protest movements in sub‐Saharan Africa have generally failed to effect progressive transformations. Efforts to achieve social change have been frustrated by governing elites that continue to utilise their vacillating and unequal relationships with the external environment to sustain power. Although the leading figures may change, the dominant African class can re‐establish leadership through new alliances with domestic and international networks of capital. To understand such ‘change‐without‐change’, this paper contributes to the growing body of literature on Antonio Gramsci's development of ‘passive revolution’. The comparative character of Gramscian analysis enables his philosophy of praxis to be translated into very different historical and geographical settings. With this in mind we draw together recent engagements with passive revolution from Geography, Politics and African Studies. In particular we develop Jean‐François Bayart's notion of extraversion, while considering it in relation to more recent philological engagements with Gramsci. Our empirical focus is the politics of transition in Malawi. In his second term in office, the autocratic and unpopular president, Bingu wa Mutharika, implemented economic policies that ran against neoliberal orthodoxy and suppressed protest during a period of crisis. Mutharika was replaced, following his death in 2012, by Joyce Banda, a previously marginalised vice‐president, who nurtured a re‐engagement with transnational capital. Working through the state, Banda led a transformation from on high and moved to impose new economically liberal policies, including a major currency devaluation, which reduced living standards for many. We draw our empirical material from Chancellor College, a major site of protest against Mutharika in 2011. Evidence from interviews with staff and students demonstrates how two episodes of revolution/restoration in Malawi, a country distant from the western historical experience, can be interpreted through Gramsci's socially differentiated understanding of politics.
The human motor neuron pools receive a dominant slow‐varying common synaptic input
Authors: Negro Francesco , Yavuz Utku Şükrü , Farina Dario
Published: May 2016

Key points

Motor neurons in a pool receive both common and independent synaptic inputs, although the proportion and role of their common synaptic input is debated.

Classic correlation techniques between motor unit spike trains do not measure the absolute proportion of common input and have limitations as a result of the non‐linearity of motor neurons.

We propose a method that for the first time allows an accurate quantification of the absolute proportion of low frequency common synaptic input (<5 Hz) to motor neurons in humans.

We applied the proposed method to three human muscles and determined experimentally that they receive a similar large amount (>60%) of common input, irrespective of their different functional and control properties.

These results increase our knowledge about the role of common and independent input to motor neurons in force control.

Motor neurons receive both common and independent synaptic inputs. This observation is classically based on the presence of a significant correlation between pairs of motor unit spike trains. The functional significance of different relative proportions of common input across muscles, individuals and conditions is still debated. One of the limitations in our understanding of correlated input to motor neurons is that it has not been possible so far to quantify the absolute proportion of common input with respect to the total synaptic input received by the motor neurons. Indeed, correlation measures of pairs of output spike trains only allow for relative comparisons. In the present study, we report for the first time an approach for measuring the proportion of common input in the low frequency bandwidth (<5 Hz) to a motor neuron pool in humans. This estimate is based on a phenomenological model and the theoretical fitting of the experimental values of coherence between the permutations of groups of motor unit spike trains. We demonstrate the validity of this theoretical estimate with several simulations. Moreover, we applied this method to three human muscles: the abductor digiti minimi, tibialis anterior and vastus medialis. Despite these muscles having different functional roles and control properties, as confirmed by the results of the present study, we estimate that their motor pools receive a similar and large (>60%) proportion of common low frequency oscillations with respect to their total synaptic input. These results suggest that the central nervous system provides a large amount of common input to motor neuron pools, in a similar way to that for muscles with different functional and control properties.
Multisegment Kinematics of the Spinal Column: Soft Tissue Artifacts Assessment
Authors: Mahallati Sara , Rouhani Hossein , Preuss Richard , Masani Kei , Popovic Milos R.
Published: May 2016

A major challenge in the assessment of intersegmental spinal column angles during trunk motion is the inherent error in recording the movement of bony anatomical landmarks caused by soft tissue artifacts (STAs). This study aims to perform an uncertainty analysis and estimate the typical errors induced by STA into the intersegmental angles of a multisegment spinal column model during trunk bending in different directions by modeling the relative displacement between skin-mounted markers and actual bony landmarks during trunk bending. First, we modeled the maximum displacement of markers relative to the bony landmarks with a multivariate Gaussian distribution. In order to estimate the distribution parameters, we measured these relative displacements on five subjects at maximum trunk bending posture. Then, in order to model the error depending on trunk bending angle, we assumed that the error grows linearly as a function of the bending angle. Second, we applied our error model to the trunk motion measurement of 11 subjects to estimate the corrected trajectories of the bony landmarks and investigate the errors induced into the intersegmental angles of a multisegment spinal column model. For this purpose, the trunk was modeled as a seven-segment rigid-body system described using 23 reflective markers placed on various bony landmarks of the spinal column. Eleven seated subjects performed trunk bending in five directions and the three-dimensional (3D) intersegmental angles during trunk bending were calculated before and after error correction. While STA minimally affected the intersegmental angles in the sagittal plane (<16%), it considerably corrupted the intersegmental angles in the coronal (error ranged from 59% to 551%) and transverse (up to 161%) planes. Therefore, we recommend using the proposed error suppression technique for STA-induced error compensation as a tool to achieve more accurate spinal column kinematics measurements. Particularly, for intersegmental rotations in the coronal and transverse planes that have small range and are highly sensitive to measurement errors, the proposed technique makes the measurement more appropriate for use in clinical decision-making processes.
Functional Validation of a Complex Loading Whole Spinal Segment Bioreactor Design
Authors: Beatty Amanda M. , Bowden Anton E. , Bridgewater Laura C.
Published: May 2016

Intervertebral disk (IVD) degeneration is a prevalent health problem that is highly linked to back pain. To understand the disease and tissue response to therapies, ex vivo whole IVD organ culture systems have recently been introduced. The goal of this work was to develop and validate the design of a whole spinal segment culturing system that loads the disk in complex loading similar to the in vivo condition, while preserving the adjacent endplates and vertebral bodies. The complex loading applied to the spinal segment (flexion–extension (FE), bilateral bending, and compression) was achieved with three pneumatic cylinders rigidly attached to a triangular loading platform. A culture container housed the spinal segment and was attached to the loading mechanism, which allowed for loading of the spinal segment. The dynamic bioreactor was able to achieve physiologic loading conditions with 100 N of applied compression and approximately 2–4 N · m of applied torque. The function of the bioreactor was validated through testing of bovine caudal IVDs with intact endplates and vertebral bodies that were isolated within 2 hrs of death and cultured for 14 days. The resulting IVD cell viability following 14 days of loading was much higher than unloaded control IVDs. The loading system accurately mimicked FE, bilateral bending, and compression motions seen during daily activities. The results indicate that this complex dynamic bioreactor may be appropriate for extended preclinical testing of vertebral-mounted spinal devices and therapies.
A Comparison of the Contact Force Distributions on the Acetabular Surface Due to Orthopedic Treatments for Developmental Hip Dysplasia
Authors: Márquez-Flórez Kalenia M. , Silva Octavio , Narváez-Tovar Carlos A. , Garzón-Alvarado Diego A.
Published: May 2016

We used a three-dimensional rigid body spring model (RBSM) to compare the contact force distributions on the acetabular surface of the infant hip joint that are produced by three orthopedic treatments for developmental dysplasia of the hip (DDH). We analyzed treatments using a Pavlik harness, a generic rigid splint, and a spica cast. The joint geometry was modeled from tomography images of a 1-year-old female. The articular cartilage was modeled as linear springs connecting the surfaces of the acetabulum and the femoral head, whereas the femur and the hip bone were considered as rigid bodies. The hip muscles were modeled as tensile-only preloaded springs. The treatments with the Pavlik harness and the generic rigid splint were modeled for an infant in supine position with a hip flexion angle of 90 deg. Also, since rigid splints are often recommended when children are initiating their gait phase, we modeled the treatment with the infant in standing position. For the spica cast, we only considered the infant in standing position with a flexion angle of 0 deg, and the fixation bar at two heights: at the ankle and at the knee. In order to analyze the effect of the hip abduction angle over the contact force distribution, different abduction angles were used for all the treatments modeled. We have found that the treatments with the infant in supine position, with a flexion angle of 90 deg and abduction angles between 60 deg and 80 deg, produce a more homogenous contact force distribution compared to those obtained for the treatments with the infant in standing position.
Double-Layer Microchannel Heat Sinks With Transverse-Flow Configurations
Authors: Ansari Danish , Kim Kwang-Yong
Published: May 2016

The performances of various transverse-flow double-layer microchannel heat sink configurations were evaluated compared to those of parallel-flow heat sink configurations via conjugate heat transfer analysis. For the analysis, three-dimensional Navier–Stokes and energy equations for steady incompressible laminar flow were solved using a finite-volume solver. Water with temperature-dependent thermophysical properties was used as a coolant. The thermal resistances were evaluated for various flow configurations of both cross-channel and parallel-channel designs with identical geometric parameters and total flow rate. Changes in the microchannel flow direction lead to remarkable changes in thermal resistance and temperature uniformity. A transverse-flow configuration exhibited the best overall performance among the tested flow configurations in terms of the thermal resistance, temperature uniformity, and pressure drop.
Assessment of Allowable Sea States During Installation of Offshore Wind Turbine Monopiles With Shallow Penetration in the Seabed
Authors: Li Lin , Guachamin Acero Wilson , Gao Zhen , Moan Torgeir
Published: May 2016

Installation of offshore wind turbines (OWTs) requires careful planning to reduce costs and minimize associated risks. The purpose of this paper is to present a method for assessing the allowable sea states for the initial hammering process (shallow penetrations in the seabed) of a monopile (MP) using a heavy lift floating vessel (HLV) for use in the planning of the operation. This method combines the commonly used installation procedure and the time-domain simulations of the sequential installation activities. The purpose of the time-domain simulation is to quantitatively study the system dynamic responses to identify critical events that may jeopardize the installation and the corresponding limiting response parameters. Based on the allowable limits and the characteristic values of the limiting response parameters, a methodology to find the allowable sea states is proposed. Case studies are presented to show the application of the methodology. The numerical model of the dynamic HLV–MP system includes the coupling between HLV and MP via a gripper device, and soil–MP interaction at different MP penetration depths. It is found that the limiting parameters are the gripper force and the inclination of the MP. The systematic approach proposed herein is general and applies to other marine operations.
Steady Characteristics of High-Speed Micro-Gas Journal Bearings With Different Gaseous Lubricants and Extreme Temperature Difference
Authors: Zhang Xueqing , Chen Qinghua , Liu Juanfang
Published: May 2016

High-speed micro-gas journal bearing is one of the essential components of micro-gas turbines. As for the operating conditions of bearings, the high-speed, high-temperature, ultra-high temperature difference along the axial direction and the species of gaseous lubricants are extremely essential to be taken into account, and the effects of these factors are examined in this paper. The first-order modified Reynolds equation including the thermal creep, which results from the extremely large temperature gradient along the axial direction, is first derived and coupled with the simplified energy equation to investigate the steady hydrodynamic characteristics of the micro-gas bearings. Under the isothermal condition, it is found that CO2 can not only improve the stability of bearings but also generate a relatively higher load capacity by some comparisons. Thus, CO2 is chosen as the lubricant to further explore the influence of thermal creep. As the rotation speed and eccentricity ratio change, the thermal creep hardly has any effect on the gas film pressure. However, the shorter bearing length can augment the thermal creep. Compared with the cases without the thermal creep, the thermal creep could remarkably destroy the stability of gas bearing, but it might slightly enhance the load capacity.
Temperature dependence of acoustic harmonics generated by nonlinear ultrasound wave propagation in water at various frequencies
Authors: Maraghechi Borna , Hasani Mojtaba H. , Kolios Michael C. , Tavakkoli Jahan
Published: May 2016

Ultrasound-based thermometry requires a temperature-sensitive acoustic parameter that can be used to estimate the temperature by tracking changes in that parameter during heating. The objective of this study is to investigate the temperature dependence of acoustic harmonics generated by nonlinear ultrasound wave propagation in water at various pulse transmit frequencies from 1 to 20 MHz. Simulations were conducted using an expanded form of the Khokhlov–Zabolotskaya–Kuznetsov nonlinear acoustic wave propagation model in which temperature dependence of the medium parameters was included. Measurements were performed using single-element transducers at two different transmit frequencies of 3.3 and 13 MHz which are within the range of frequencies simulated. The acoustic pressure signals were measured by a calibrated needle hydrophone along the axes of the transducers. The water temperature was uniformly increased from 26 °C to 46 °C in increments of 5 °C. The results show that the temperature dependence of the harmonic generation is different at various frequencies which is due to the interplay between the mechanisms of absorption, nonlinearity, and focusing gain. At the transmit frequencies of 1 and 3.3 MHz, the harmonic amplitudes decrease with increasing the temperature, while the opposite temperature dependence is observed at 13 and 20 MHz.
Flight parameter estimation using instantaneous frequency and time delay measurements from a three-element planar acoustic array
Authors: Lo Kam W.
Published: May 2016

The acoustic signal emitted by a turbo-prop aircraft consists of a strong narrowband tone superimposed on a broadband random component. A ground-based three-element planar acoustic array can be used to estimate the full set of flight parameters of a turbo-prop aircraft in transit by measuring the time delay (TD) between the signal received at the reference sensor and the signal received at each of the other two sensors of the array over a sufficiently long period of time. This paper studies the possibility of using instantaneous frequency (IF) measurements from the reference sensor to improve the precision of the flight parameter estimates. A simplified Cramer-Rao lower bound analysis shows that the standard deviations in the estimates of the aircraft velocity and altitude can be greatly reduced when IF measurements are used together with TD measurements. Two flight parameter estimation algorithms that utilize both IF and TD measurements are formulated and their performances are evaluated using both simulated and real data.
Acoustic reflections in the water column of Krishna-Godavari offshore basin, Bay of Bengal
Authors: Sinha Satish K. , Dewangan Pawan , Sain Kalachand
Published: May 2016

Seismic oceanographic studies from various oceans worldwide have indicated that the acoustic reflections are mostly observed along thermal boundaries within the water column. However, the authors present a case study of seismic data from Krishna-Godavari Basin which shows that salinity variations also play an important role in the occurrence of water column reflections. The observed reflection is modeled using the reflectivity series derived from the salinity and temperature profiles from a nearby Conductivity-Temperature-Depth (CTD) location. Sensitivity analysis of temperature and salinity on soundspeed shows that the effect of salinity cannot be ignored for modeling acoustic reflections. The synthetic seismogram matches well with the observed reflection seismic data. Remarkable similarities between the reflection seismic and the salinity profile in the upper thermocline suggest the importance of salinity variations on the water column reflection. Furthermore, impedance inversion of the reflectivity data reveals several thermohaline structures in the water column. The origin of these thermohaline structures is largely unaddressed and may be attributed to the fresh water influx coming from Himalayan and Peninsular rivers or due to the presence of different water masses in the Indian Ocean which warrants a detailed study using concurrent seismic and CTD data.
Effects of musical and linguistic experience on categorization of lexical and melodic tones
Authors: Chang Daniel , Hedberg Nancy , Wang Yue
Published: May 2016

This study investigated the categorization of Mandarin lexical tones and music melodic tones by listeners differing in linguistic and musical experience (English musicians, English non-musicians, and Mandarin non-musicians). Linguistic tonal continua were created from the Mandarin rising to level, and falling to level tones. Melodic continua were created by varying the note D under the context of C and E. The tasks involved tone discrimination and identification. Results revealed that musical training facilitated Mandarin tone categorization, with English musicians' tone identification approximating native Mandarin patterns, being more categorical than English non-musicians'. However, English musicians showed higher discrimination accuracy than Mandarin listeners but not English non-musicians. This suggests that musical experience was not advantageous in discriminating linguistic tonal variations, which requires listeners to ignore subtle physical differences in order to make categorical judgments. Similarly, Mandarin tone experience affected melodic tone identification, with Mandarin non-musicians approximating English musicians, showing more categorical patterns than English non-musicians. In contrast, Mandarin non-musicians' melodic discrimination was the poorest among the three groups, indicating that their experience with linguistic tone categorization may have decreased their sensitivity to fine-grained pitch variations. These results demonstrate bi-directional transfer of pitch proficiency between speech and music as a function of experience.
Auditory research in fish: From the goldfish to zebrafish
Authors: Lu Zhongmin
Published: May 2016

Dr. Richard R. Fay has made seminal contributions to our understanding of hearing and bioacoustics in fish. I was fortunate to be trained as a Ph.D. student in fish auditory physiology under his guidance. For this presentation, I will first review my early graduate work on auditory processing in goldfish with Dick and express my deepest appreciation and thanks to him for helping me start my postdoctoral training in Dr. Arthur Popper’s lab as well as his positive influence on my academic career. For the second part of the talk, I will switch to my current research focus on genetic hearing loss using zebrafish. For the past decade, the zebrafish (Danio rerio) has emerged as an important vertebrate model for biomedical research because it combines many advantages such as excellent embryology, exceptional in vivo imaging, and powerful genetics in one organism. Collaborating with an otolaryngologist and a clinical geneticist in the University of Miami Miller School of Medicine, my lab has been assessing auditory functions of novel deafness genes. I will show an example of our project on the zebraifsh model for sensorineural hearing loss using molecular, genetic, behavioral, confocal imaging, and electrophysiological approaches.
An introduction to the acoustical oceanography technical committee
Authors: Barclay David R. , Bassett Christopher
Published: May 2016

Commonly used air-side remote sensing techniques (e.g., cameras, GPS, wireless communications, and radar) are not suitable for many oceanographic applications because seawater is opaque to electromagnetic radiation. Acoustic signals, on the other hand, propagate relatively well underwater and can be used for remote sensing, imaging, and communications. The Acoustical Oceanography (AO) technical committee (TC) focuses on the development and use of acoustical techniques to understand geological, biological, chemical, and physical oceanographic parameters and processes. Research falling under the auspices of the AO technical committee is inherently interdisciplinary, overlapping with the Animal Bioacoustics, Signal Processing, and Underwater Acoustics technical committees. This presentation will introduce current AO research topics and the ways in which acoustical oceanography is advancing our knowledge of the ocean and its boundaries.
Introduction to the speech communication technical committee
Authors: Munson Benjamin
Published: May 2016

The Speech Communication technical committee is one of the oldest and largest in the Acoustical Society of America. Our work covers three broad areas: speech production, speech perception, and computer speech processing. Studies presented at our meetings and in our journal cover languages spoken all over the world, including widely spoken languages like Mandarin and Spanish, and less widely spoken languages like Zoque and Tlingit. We study individuals across the lifespan, including both typical speakers and ones with speech, language, and hearing impairments. This brief presentation will highlight three recent presentations given at the society. These illustrate the breadth of our work, our centrality in the ASA, and our connections to the other technical committees.
Architectural acoustics—Hear here
Authors: Case Alexander U.
Published: May 2016

The discipline of Architectural Acoustics consistently produces more than 100 papers across six or more special sessions, at each meeting of the ASA. Student paper awards, student design competitions, and Knudsen lectures augment these activities. Joint sessions, particularly with noise, musical acoustics, psychological and physiological acoustics, and signal processing in acoustics, add more still to the architectural acoustics goings-on at every ASA conference. The sphere of influence is not limited to ASA alone, as TCAA members participate in the Green Construction Code of the International Code Council, Society of Motion Picture and Television Engineers Study Group: Movie Theater Sound System Measurement and Adjustment Techniques, Classroom Acoustics Standards, the American Institute of Architects Continuing Education System, and more. This busy committee also produces a steady stream of publications documenting recent work and deciphering standards for key stakeholders. Anyone with an interest in the field will find many opportunities to advance their own expertise, build a network of colleagues, friends and mentors, and contribute to the essential activities of the Technical Committee on Architectural Acoustics.
Results of a visitor survey of the acoustic environment at the Grand Canyon National Park
Authors: Pamidighantam Pranav K. , Schomer Paul D.
Published: May 2016

For the last decade, multiple studies have been conducted at nationalparks using the traditional uni-polar annoyance questions and the dose-response concept to determine the effects of aircraft noise on park visitors. This survey used pleasantness as a bipolar scale and breaks the hike into segments so as to understand the overall hike’s assessment through its parts. This survey was conducted on three different trails at the Grand Canyon: the Hermit trail, a backcountry trail with a large amount of aircraft noise; the Widforss trail, a backcountry trail with minimal aircraft noise; and the Bright Angel trail, a maintained trail with a small amount of aircraft noise but many hikers. Helicopter noise is found to be the only major unpleasant noise. Segments for which no aircraft are noticed are judged to be primarily very pleasant. The “average” judgment with helicopters noticed falls between neutral and slightly pleasant, which is a drop of almost three categories out of a total of seven. The study finds that visitor perception of pleasantness of the acoustic environment at the Grand Canyonis significantly, negatively affected by helicopter overflights near trails.
Measurable domain for crowd noise in modern stadiums and arenas
Authors: Navvab Mojtaba
Published: May 2016

The noise generated by the organized fans or crowds during sporting events has created a challenge for sports facility management. The new demand for full compliance to national sports league rules on crowd noise, as well as health regulations ordinance on noise, require new methods in estimating and or measuring such environmental conditions. Given their dynamic range and possible classification, noise levels generated by large crowds have influenced the outcome of games. Recent analysis of the available data shows this situation has provided more excitement for the spectators and greater participation in the events. However, sound intensity of 95 to 110 dBA is now the typically reported range of recorded noise levels within various sports stadiums and arenas. This paper describes an integrated method utilizing ray tracing in simulating the sound path, and delay-sum beamforming in the time and frequency domains using the spherical wave concept, measuring the sound with 120 channel data recorders, and utilizing various acoustic software for data reduction, computer modeling, simulation, and analysis within ten selected sports facilities. The results show the associated room acoustic characteristics and the measurable domain for crowd noise and acoustic signature of modern stadiums and arenas that represent the significant component of all architectural elements with their contributions to the space including allowable noise dose as estimated for spectators’ exposure to noise at a safe rate by NIOSH and NFPA 72 and compliance.
Linking the viscous grain-shearing mechanism of wave propagation in marine sediments to fractional calculus
Authors: Pandey Vikash , Holm Sverre
Published: May 2016

This work is an extension of Pandey and Holm [Abstract, JASA (2015)] and builds on Buckingham's viscous grain-shearing (VGS) model [JASA (2007)]. The VGS model is an extension to the grain-shearing mechanism initially proposed to explain wave propagation in marine sediments. We find that the material impulse response function obtained from the VGS model is characterized by power-law terms which are inherent to the framework of fractional calculus. The VGS model in the fractional framework yields two equations; a fractional-order wave equation for the compressional wave and a modified fractional-order diffusion-wave equation for the shear wave. The order of the fractional equations as well as the two characteristic time constants are identified as the physical parameters of the medium. The viscous dissipation incurred due to inter-granular sliding across the pore-fluid modifies the low frequency behavior of the dispersion plots significantly. The low frequency behavior (<1 Hz) for both compressional and shear wave show normal dispersion of decreasing phase velocity with increasing frequency. These features were not observed in the original VGS model. The overall goal is to establish a physically based fractional framework, which can effectively incorporate the role of different material parameters in wave propagation.
Development of smart noise control technology
Authors: Chen Lingguang , Wu Sean F.
Published: May 2016

Effective noise control requires correctly identifying the components of structural vibrations that can actually produce sound. Standard practices in engineering applications include experimental modal analysis, transfer path analysis, etc., that are ad hoc in nature and oftentimes ineffective at all. This paper presents a new strategy that aims at identifying and suppressing the most critical forced-vibro-acoustic components (F-VACs) of vibrating structures that are directly responsible for structure-borne sound radiation. The F-VACs may be extracted from the transfer function that correlates the normal surface velocity of a vibrating structure to the resultant sound pressure, and their relative contributions be identified by singular value decomposition. Unlike transfer path analysis, the transfer function in this case can be obtained theoretically through the HELS-based NAH, rather than experimentally, thus significantly improving the effectiveness of this approach. Moreover, a laser vibrometer is used to collect input data, which greatly simplifies the complexity involved in data acquisition process of traditional NAH. Experimental validations of using this new strategy to reduce noise emission from an arbitrarily shaped vibrating structure are presented, and its effectiveness is compared with that of experimental modal analysis.
The perception of breathy voice in Gujarati
Authors: Nelson Max
Published: May 2016

Breathy voice, also referred to as murmur, is characterized by an increased open quotient and increased airflow. Acoustical correlates of breathiness include an increased spectral slope, most notably as measured by H1-H2 and H1-A3, as well as an increase in noise as measured by harmonics-to-noise ratio and cepstral peak prominence. Gujarati is relatively unique in that it contains phonemic breathiness in both consonants and vowels, creating meaningfully different Cɦ V and CV̤ sequences. Acoustic analysis of this contrast indicates that while the acoustic correlates of breathiness are consistent across these two sequences, there are differences in both the timing and magnitude of the cues of breathiness (Esposito and Khan 2012). Perceptual studies have indicated that speakers of languages with phonemic breathiness are capable of reliably differentiating breathy and modal sounds, but no study to date has addressed the perceptual salience of the timing and degree differences associated with breathiness in consonants versus vowels. The present study addresses the potential confusability of Cɦ V and CV̤ sequences in Gujarati through a series of perception tasks. Results indicate that there is an asymmetrical relationship between Cɦ V and CV̤ sequences that may be attributable to differences in the magnitude and timing of acoustic cues.
Can audio-haptic speech be used to train better auditory speech perception?
Authors: Dorsi Josh , Rosenblum Lawrence D. , Dias James W. , Ashkar Dana
Published: May 2016

Training with audio-visual speech improves subsequent auditory speech perception more so than training with auditory-alone speech (e.g., Bernstein, et al., 2013). What is the source of this bimodal training advantage? One explanation is that perceivers rely on learned bimodal associations. Alternatively, perceivers could be exploiting natural, amodal regularities available in both the auditory and visual signals. To test this question, multisensory training stimuli were tested for which observers had no bimodal associative experience. It is known that felt articulations —acquired by placing a hand on a speaker’s face— can provide information for speech perception (see Trielle et al., 2014, for a review). Importantly, these effects are found in participants with no prior experience perceiving speech through touch. If training with audio-haptic speech improves auditory speech perception, then this bimodal advantage cannot be due to learned associations but likely reflects sensitivity to amodal information. To test this hypothesis, participants either heard, or heard and felt, a speaker’s speech. Participants subsequently identified words from a set of novel audio-alone sentences. Preliminary data indicate that audio-haptic speech training improves subsequent auditory-only perception more than audio-only training. These results challenge a learned association account for the bimodal training advantage.
Morphological effects on formant movement in spontaneous speech
Authors: Sims Michelle , Tucker Benjamin V. , Baayen Harald
Published: May 2016

In the present study we investigate the role of morphology in the production of vowel formant movement and centralization. Our data consist of 74 monosyllabic irregular English verbs (6028 tokens) that differ between their present/past tense forms on a single vowel (e.g., sing/sang). For each vowel, we measured F1 and F2 contours and Euclidean distances from speakers’ vowel space centres (measured at the vowel midpoint). A generalized additive model of the formant trajectories and a linear mixed effects regression model of the vowel centralization distances were created comparing two morphological predictors: verb tense (past or present), and paradigmatic support for the vowel. Paradigmatic support was measured using naïve discriminative learning as a metric which determined the association strength between a vowel and tense. A strong association with the past tense is evidence for greater paradigmatic support (i.e., it is more discriminating) while a vowel strongly associated with the present tense has low support. Our results indicate that the morphological predictors have an overall effect on formant movement (both in the past tense and with low paradigmatic support) and vowel centralization. However, the morphological effects differ between individual vowels.
Perception of voice onset time in Singapore English
Authors: Shin Priscilla Z.
Published: May 2016

This study investigates how voice onset time (VOT) is perceived in Singapore English (SgE). SgE research acknowledges that Singaporeans linguistically accommodate their listeners—varying between using Standard Singapore English (SSE) or Singlish (colloquial SgE) depending on addressee. Liu 2011 (n.p.) suggests these linguistic accommodations are reflected in VOT production, finding Singaporeans to produce more short-lag VOT (indicative of Singlish) when speaking to other Singaporeans and longer VOT (indicative of SSE) when speaking to Americans. Though these are sub-categorical shifts, they demonstrate the utility of VOT in speakers’ efforts when accommodating listeners. The current study tests whether VOT is also available as a salient and social perceptual cue. Three listening experiments investigate (1) Singaporeans’ baseline categorical perception of a /ba/-/pa/ continuum, (2) whether this baseline is affected when heard with socially salient pictures (i.e., linguistic stereotypes—an ah lian or a business woman), and (3) whether dialectal carrier phrases—whether stimuli are presented within a SSE or Singlish phrase—affects perception of the same stimuli. Preliminary results show listener age and educational background, which allude to an effect of dialectal experience (Sumner and Samuel 2009), play important roles in the perception of VOT.
Acoustic metamaterials: From theory to practice
Authors: Norris Andrew
Published: May 2016

Why have acoustic metamaterials appeared on the scene in the last few years, and what are they anyway? The original defining property of a metamaterial is that it achieves effects not found in nature, with the more effects the better. The acoustic cloak, justifiably the best known example, redirects sounds around the cloaked object regardless of the incident acoustic wave. The common theme of the cloak and of the many other devices that have been proposed is defiance of the intuitive laws of acoustical physics as much as possible. This requires strange concepts such as acoustic anisotropy, allowing sound to have speed that depends on direction, and transformation acoustics which is the basis for acoustic cloaking. Periodic structures, aka phononic crystals, play a central role in practical applications. The tutorial will provide a comprehensive introduction to these ideas without the need for detailed mathematics. While the field of metamaterials originated in electromagnetics before it migrated over to acoustics, there are fundamental differences between the two fields, the most obvious arising from the fact the acoustic wave speeds are not strictly limited, a distinction which leads to profound consequences. Acoustic wavelengths are also typically orders of magnitude larger than optical wavelengths, meters versus microns, which makes the acoustic problems easier, in principle. This practical advantage is perhaps the main reason for the intense interest in the field by funding agencies and researchers alike.
Methods for the identification of intermittent and unpredictable noises
Authors: Reuter Eric L.
Published: May 2016

Acoustical consultants are often asked to identify noises that are intermittent and unpredictable, such that attended observation is impractical. This paper presents methods for recording and identifying such events using unattended long-term recordings of sound and vibration, and for efficiently analyzing the voluminous data that can accumulate during such studies.
Room acoustic design, measurement, and simulation techniques to reduce hospital noises within patients' environment
Authors: Navvab Mojtaba
Published: May 2016

Hospitalized patients and clinical staff identify noise as a major stressor. Environmental hospital noise raises ambient noise levels significantly above ideal levels. Options to reduce hospital noise include methods to modify noise, such as closing doors, adjusting hospital equipment, hospital personnel behaviors, and clinical alarms such as wireless communication devices for staff and future “smart” algorithms for patient-specific alarm thresholds. This study utilizes the beamforming techniques to localize and examines basic characteristic of sound field through measurements and simulation of noise in an environment that affects the patient’s audio perception, and collects evidence for impact of noise intensity on patient hearing toward reduction of the noise sources in hospital rooms. The profiles of noise levels for their time and frequency domain as being reflected, absorbed, or refracted within typical patient’s room are determined. The difference in applications of various architectural solutions to mitigate noise in hospitals within patient environment is estimated. The results contribute toward architectural room acoustic design solution(s) to reduce acoustic disruption of sleep or rest with adequate information and reproducible data to accelerate design decision-making process while providing practical solutions such as geometric modification to room architectural elements as compared to theoretical offerings by the research community.