bluuebunny/crossref_metadata_2025 huggingface dataset:
Mosquito and West Nile virus surveillance in northeast Montana, U.S.A., 2005 and 2006
Authors: FRIESEN K. M. , JOHNSON G. D.
Published: May 2013

Mosquito and West Nile virus (WNV) surveillance was conducted on a national wildlife refuge in northeast Montana in 2005 and 2006, during which outbreaks of WNV in a colony of American white pelicans (Pelecanus erythrorhynchos Gmelin) (Pelecaniformes: Pelecanidae) resulted in juvenile mortality rates of ∼ 31%. Both years, floodwater species Ochlerotatus dorsalis (Meigen) (Diptera: Culicidae), Aedes vexans (Meigen) (Diptera: Culicidae) and Ochlerotatus flavescens (Muller) (Diptera: Culicidae) comprised 78% of the total collection and heightened host‐seeking activity was observed from mid‐June to mid‐July. Culex tarsalis Coquillett (Diptera: Culicidae) was most active from mid‐July to mid‐August and comprised 18% of the collection in 2005 and 20% in 2006. However, fewer than 10% of the Cx. tarsalis females collected in 2006 were obtained adjacent to the pelicans' nesting grounds. Minimum infection rates per 1000 Cx. tarsalis tested for WNV were 1.36 in 2005 and 1.41 in 2006. All pools in which WNV was detected in 2006 were composed of females collected 10 km from the nesting grounds. Substantial juvenile pelican mortality in 2006 despite reductions in the population of the primary vector and in mosquito infection rates near the colony suggests that the methods used to detect the introduction of WNV were too coarse and that amplification of the virus within the colony may reflect causes other than mosquito infection.
Stored carbon partly fuels fine‐root respiration but is not used for production of new fine roots
Authors: Lynch Douglas J. , Matamala Roser , Iversen Colleen M. , Norby Richard J. , Gonzalez‐Meler Miquel A.
Published: May 2013

The relative use of new photosynthate compared to stored carbon (C) for the production and maintenance of fine roots, and the rate of C turnover in heterogeneous fine‐root populations, are poorly understood.

We followed the relaxation of a 13C tracer in fine roots in a Liquidambar styraciflua plantation at the conclusion of a free‐air CO2 enrichment experiment. Goals included quantifying the relative fractions of new photosynthate vs stored C used in root growth and root respiration, as well as the turnover rate of fine‐root C fixed during [CO2] fumigation.

New fine‐root growth was largely from recent photosynthate, while nearly one‐quarter of respired C was from a storage pool. Changes in the isotopic composition of the fine‐root population over two full growing seasons indicated heterogeneous C pools; < 10% of root C had a residence time < 3 months, while a majority of root C had a residence time > 2 yr.

Compared to a one‐pool model, a two‐pool model for C turnover in fine roots (with 5 and 0.37 yr−1 turnover times) doubles the fine‐root contribution to forest NPP (9–13%) and supports the 50% root‐to‐soil transfer rate often used in models.
Unified changes in cell size permit coordinated leaf evolution
Authors: Brodribb Tim J. , Jordan Greg J. , Carpenter Raymond J.
Published: May 2013

The processes by which the functions of interdependent tissues are coordinated as lineages diversify are poorly understood.

Here, we examine evolutionary coordination of vascular, epidermal and cortical leaf tissues in the anatomically, ecologically and morphologically diverse woody plant family Proteaceae.

We found that, across the phylogenetic range of Proteaceae, the sizes of guard, epidermal, palisade and xylem cells were positively correlated with each other but negatively associated with vein and stomatal densities. The link between venation and stomata resulted in a highly efficient match between potential maximum water loss (determined by stomatal conductance) and the leaf vascular system's capacity to replace that water. This important linkage is likely to be driven by stomatal size, because spatial limits in the packing of stomata onto the leaf surface apparently constrain the maximum size and density of stomata.

We conclude that unified evolutionary changes in cell sizes of independent tissues, possibly mediated by changes in genome size, provide a means of substantially modifying leaf function while maintaining important functional links between leaf tissues. Our data also imply the presence of alternative evolutionary strategies involving cellular miniaturization during radiation into closed forest, and cell size increase in open habitats.
Physiological and metabolic consequences of autophagy deficiency for the management of nitrogen and protein resources in Arabidopsis leaves depending on nitrate availability
Authors: Guiboileau Anne , Avila‐Ospina Liliana , Yoshimoto Kohki , Soulay Fabienne , Azzopardi Marianne , Marmagne Anne , Lothier Jérémy , Masclaux‐Daubresse Céline
Published: May 2013

Autophagy is present at a basal level in all plant tissues and is induced during leaf ageing and in response to nitrogen (N) starvation. Nitrogen remobilization from the rosette to the seeds is impaired in autophagy mutants. This report focuses on the role of autophagy in leaf N management and proteolysis during plant ageing.

Metabolites, enzyme activities and protein contents were monitored in several autophagy‐defective (atg) Arabidopsis mutants grown under low and high nitrate conditions.

Results showed that carbon (C) and N statuses were affected in atg mutants before any senescence symptoms appeared. atg mutants accumulated larger amounts of ammonium, amino acids and proteins than wild type, and were depleted in sugars. Over‐accumulation of proteins in atg mutants was selective and occurred despite higher endopeptidase and carboxypeptidase activities. Specific over‐accumulation of the ribosomal proteins S6 and L13 subunits, and of catalase and glutamate dehydrogenase proteins was observed. atg mutants also accumulated peptides putatively identified as degradation products of the Rubisco large subunit and glutamine synthetase 2 (GS2). Incomplete chloroplast protein degradation resulting from autophagy defects could explain the higher N concentrations measured in atg rosettes and defects in N remobilization.

It is concluded that autophagy controls C : N status and protein content in leaves of Arabidopsis.
The mechanism of ORFH79 suppression with the artificial restorer fertility gene Mt‐GRP162
Authors: Hu Jun , Huang Wenchao , Huang Qi , Qin Xiaojian , Dan Zhiwu , Yao Guoxin , Zhu Renshan , Zhu Yingguo
Published: May 2013

The restoration fertility complex (RFC) was previously identified in Honglian (HL)‐cytoplasmic male sterility (CMS) rice (Oryza sativa), and glycine‐rich protein 162 (GRP162) is responsible for binding to the CMS‐associated transcript atp6‐orfH79.

Here, we engineered a recombinant GRP162 containing the mitochondrial transit peptide, termed Mt‐GRP162, as an artificial restorer of fertility (Rf) gene. Mt‐GRP162 was confirmed to bind to CMS‐associated RNA and to localize to the mitochondria. The transgenic plants showed restored fertility with partially functional pollen.

We found that the expression of ORFH79 decreased in transgenic plants, while the expression of atp6‐orfH79 was not changed. These findings indicate that Mt‐GRP162 restores fertility by suppressing the expression of the cytotoxic protein ORFH79 at the post‐transcriptional level rather than via the cleavage of atp6‐orfH79 in the presence of RFC.

These findings contribute to our understanding of the mechanisms of restoration through diverse pathways.
Common pathways to tumor rejection
Authors: Wang Ena , Bedognetti Davide , Tomei Sara , Marincola Francesco M.
Published: May 2013

The control of tumor growth by the host's immunosurveillance is centered on the activation of interferon (IFN) pathways. In particular, direct study of tumors by various groups has uncovered an IFN‐γ–related signature whose presence is consistently associated with better prognosis, predisposition to respond to immunotherapy, and, in its extreme manifestation, the acute phases of tumor rejection. Together, and related to the IFN‐γ–associated signature, a cluster of genes are coordinately expressed that we refer to as the immunologic constant of rejection (ICR). Activation of ICR components is observed in all forms of immune‐mediated, tissue‐specific destruction, including autoimmunity, allograft rejection, graft‐versus‐host disease, and killing of affected cells during the acute phases of infection that leads to clearance of pathogens. Thus, tumor rejection is a facet of a general and conserved mechanism that favors (tumor rejection, clearance of pathogen) or encumbers (graft rejection, autoimmunity) the organism. Here, we summarize progress in the understanding of its genesis, outline the difficulties, and propose a strategy for understanding the causes of tumor rejection.
Molecular programming of steady‐state dendritic cells: impact on autoimmunity and tumor immune surveillance
Authors: Johnson Dylan J. , Ohashi Pamela S.
Published: May 2013

Dendritic cells are master regulators of immunity. Immature dendritic cells are essential for maintaining self‐tolerance, while mature dendritic cells initiate a variety of specialized immune responses. Dendritic cell quiescence is often viewed as a default state that requires exogenous stimuli to induce maturation. However, recent studies have identified dendritic cell quiescence factors that actively program dendritic cells to an immature state. In the absence of these factors, dendritic cells spontaneously become immunogenic and can induce autoimmune responses. Herein we discuss two such factors, NF‐κB1 and A20, that preserve dendritic cell immaturity through their regulation of NF‐κB signaling. Loss of either of these factors increases dendritic cell immunogenicity, suggesting that they may be important targets for enhancing dendritic cell–based cancer immunotherapies. Alternatively, defects in molecules critical for maintaining steady‐state DCs may provide novel biomarkers that identify patients who have enhanced natural antitumor immunity or that correlate with better responses to various immunotherapies.
Integration of epidemiology, immunobiology, and translational research for brain tumors
Authors: Okada Hideho , Scheurer Michael E. , Sarkar Saumendra N. , Bondy Melissa L.
Published: May 2013

We recently identified a pivotal role for the host type I interferon (IFN) pathway in immunosurveillance against de novo mouse glioma development, especially through the regulation of immature myeloid cells (IMCs) in the glioma microenvironment. The present paper summarizes our published work in a number of areas. We have identified single‐nucleotide polymorphisms (SNPs) in human IFN genes that dictate altered prognosis of patients with glioma. One of these SNPs (rs12553612) is located in the promoter of IFNA8 and influences its activity. Conversely, recent epidemiologic data show that chronic use of nonsteroidal anti‐inflammatory drugs lowers the risk of glioma. We translated these findings back to our de novo glioma model and found that cyclooxygenase‐2 inhibition enhances antiglioma immunosurveillance by reducing glioma‐associated IMCs. Taken together, these findings suggest that alterations in myeloid cell function condition the brain for glioma development. Finally, in preliminary work, we have begun applying novel immunotherapeutic approaches to patients with low‐grade glioma with the aim of preventing malignant transformation. Future research will hopefully better integrate epidemiological, immunobiological, and translational techniques to develop novel, preventive approaches for malignant gliomas.
An appraisal of the fossil record for the Cirolanidae (Malacostraca: Peracarida: Isopoda: Cymothoida), with a description of a new cirolanid isopod crustacean from the early Miocene of the Vienna Basin (Western Carpathians)
Authors: HYŽNÝ MATÚŠ , BRUCE NIEL L. , SCHLÖGL JÁN
Published: May 2013

Abstract: Isopod crustaceans are rarely preserved in the fossil record. Herein, an appraisal of the fossil record for the cirolanid isopods is presented. Five genera are briefly discussed, includingBathynomus,Brunnaega,Palaega,PseudopalaegaandCirolana. A key for the cirolanid genera known to date from the fossil record is provided based mostly on pleotelson characters. From the early Miocene of the Slovak part of the Vienna Basin,Cirolana feldmannisp. nov. is described being only the fifth fossilCirolanaspecies known to date and one of the few with preserved appendages. The material exhibits preservation suggesting biphasic moulting; the mode of preservation suggests a rather short time between shedding the posterior and anterior parts of the exoskeleton instead of hours or even days known in extant taxa. As no subsequent transport or physical disturbance was inferred, the specimens can be stated asin situpreservation. From the palaeoecological point of view, it is concluded thatCirolana feldmannisp. nov. is the first unequivocal fossil deep‐waterCirolanaas suggested by the accompanied fauna.
A new specimen of theTriassic pistosauroidYunguisaurus, with implications for the origin ofPlesiosauria (Reptilia,Sauropterygia)
Authors: Sato Tamaki , Zhao Li‐Jun , Wu Xiao‐Chun , Li Chun
Published: May 2013

An adult skeleton of the pistosauroid sauropterygianYunguisaurus liaereveals a number of morphological features not observed in the holotype, such as the complete morphology of the skull roof, stapes, atlas and axis, ventral view of the postcranium, and nearly complete limbs and tail. Size and morphological differences between the two specimens are mostly regarded as ontogenetic variation, and newly added data did not affect the phylogenetic relationships with other pistosauroids significantly. The number of mesopodia (11 carpals and 8 tarsals) exceeds that known in any otherTriassic marine reptiles and does not serve as a precursor of the plesiosaurian pattern with fewer mesopodia of different topology; it demonstrates variability of the limb morphology among theTriassic pistosauroids. The pectoral girdles ofCorosaurus,AugustasaurusandYunguisaurusmay indicate early stages of the adaptation towards the plesiosaurian style of paraxial limb movements with ventroposterior power stroke.
Bilinear Form and N‐Shock‐Wave Solutions for a (2+1)‐Dimensional Breaking Soliton Equation in Certain Fluids with the Bell Polynomials and Auxiliary Function
Authors: Jiang Yan , Tian Bo , Li Min , Wang Pan
Published: May 2013

In this paper, we will investigate a (2+1)‐dimensional breaking soliton (BS) equation for the (2+1)‐dimensional collision of a Riemann wave with a long wave in certain fluids. Using the Bell polynomials and an auxiliary function, we derive a new bilinear form for the (2+1)‐dimensional BS equation, which is different from those in the previous literatures. One‐, two‐ and N‐shock‐wave solutions are obtained with the Hirota method and symbolic computation. One shock wave is found to be able to stably propagate. Two shock waves are observed to have the parallel collision, oblique collision, and stable propagation of the V‐type structure. In addition, we present the collision between one shock wave and V‐type structure, and the collision between two V‐type structures.
Wavelet Thresholding Estimation in a Poissonian Interactions Model with Application to Genomic Data
Authors: Sansonnet Laure
Published: May 2013

This paper deals with the study of dependencies between two given events modelled by point processes. In particular, we focus on the context of DNA to detect favoured or avoided distances between two given motifs along a genome suggesting possible interactions at a molecular level. For this, we naturally introduce a so‐called reproduction function h that allows to quantify the favoured positions of the motifs and that is considered as the intensity of a Poisson process. Our first interest is the estimation of this function h assumed to be well localized. The estimator based on random thresholds achieves an oracle inequality. Then, minimax properties of on Besov balls are established. Some simulations are provided, proving the good practical behaviour of our procedure. Finally, our method is applied to the analysis of the dependence between promoter sites and genes along the genome of the Escherichia coli bacterium.
Reciprocal regulation of calcium‐/phosphate‐regulating hormones in cyclists during the Giro d'Italia 3‐week stage race
Authors: Lombardi G. , Corsetti R. , Lanteri P. , Grasso D. , Vianello E. , Marazzi M. G. , Graziani R. , Colombini A. , Galliera E. , Corsi Romanelli M. M. , Banfi G.
Published: May 2013

Calcium and phosphate are essential for cell functions, and their serum concentrations result from the balance between intestinal absorption, bony storage, and urinary excretion. Fibroblast growth factor 23 (FGF23), expressed by osteocytes and osteoblasts, acts in the kidney, leading to hypophosphatemia and low 1,25‐dihydroxycholecalciferol synthesis, but suppresses parathyroid function. The aim of this study was to explore the effects of a high‐energy demanding cycling race on this bone–kidney–parathyroid axis. We studied nine cyclists during the 2011 Giro d'Italia stage race. Pre‐analytical and analytical phases followed academic and anti‐doping recommendations. Serum parathyroid hormone (PTH), 25(OH)D, total calcium, inorganic phosphorus, and plasma FGF23 were measured on days −1, 12, and 22 and corrected for changes in plasma volume. Dietary calcium and phosphorus, anthropometric parameters (height, weight, and body mass index) and indexes of metabolic effort (net energy expenditure, power output) were recorded. Dietary calcium and phosphorus intakes were kept at the same levels throughout the race. Twenty‐five (OH)D, PTH, and calcium concentrations remained stable. FGF23 increased 50% with a positive correlation with the indexes of metabolic effort and, consequently, phosphorous decreased, although only in the first half. The strong metabolic effort acts on the bone–kidney–parathyroid system, and the rise in FGF23 plasma concentration might be aimed at maintaining calcium and phosphorus homeostasis.
Prevalence of high‐risk human papilloma virus among women with hepatitis C virus before liver transplantation
Authors: Tarallo P.A. , Smolowitz J. , Carriero D. , Tarallo J. , Siegel A. , Jia H. , Emond J.C.
Published: May 2013

Background

We sought to assess the prevalence and risk factors for high‐risk human papillomavirus (HPV) infection among female liver transplant (LT) candidates. Traditional health screening before LT listing has included Pap smear and is typically carried out by the patient's local provider. The prevalence of high‐risk HPV in this population has not been studied.

Methods

With Institutional Review Board approval, 62 LT candidates received a liquid‐based Pap smear with high‐risk HPV testing as part of their pre‐transplant evaluation by a single provider. Clinical variables included age, ethnicity, insurance status, prior Pap smear, and HPV results, HPV risk factors including age of first intercourse, number of lifetime partners, last sexual activity, smoking, birth control pill use, history of sexually transmitted infections, human immunodeficiency virus status, immunosuppressive medication, medical diagnoses, prescribed medications, and history of hepatitis A, B, C, or D.

Results

The 62 women had a median age of 56 years, and 39% had high‐risk behavior known to be associated with HPV. Ten of 62 patients (16.1%) had high‐risk HPV at baseline screening, 5 of whom had atypical cytology. All of the patients who were positive for high‐risk HPV had an etiology of hepatitis C virus (HCV) as the underlying cause of liver disease, with the majority (90%) having no history of high‐risk behavior for HPV. In contrast, all patients with high‐risk behavior who were HCV negative were HPV negative. Fisher's exact test demonstrated a statistically significant relationship between HPV and HCV; odds ratio = 24.4, 95% confidence interval, 1.4, 438.7, P‐value = 0.0013. None of the other potential risk factors were associated with HPV in this cohort.

Conclusions

In this study, we provide evidence of a strong association between HCV and HPV in LT candidates, which has not been previously reported. HPV positivity was observed in non‐sexually active women, suggesting a reactivation of dormant HPV. An association between hepatitis C and high‐risk HPV could involve impairment of T‐cell function by hepatitis C. These data support close surveillance in women's health screening for LT candidates. Further studies to characterize immune responses in these patients will be in order.
Mechanical clot damage from cavitation during sonothrombolysis
Authors: Weiss Hope L. , Selvaraj Prashanth , Okita Kohei , Matsumoto Yoichiro , Voie Arne , Hoelscher Thilo , Szeri Andrew J.
Published: May 2013

Recent studies have shown that high intensity focused ultrasound (HIFU) accelerates thrombolysis for ischemic stroke. Although the mechanisms are not fully understood, cavitation is thought to play an important role. The goal of this paper is to investigate the potential for cavitation to cause mechanical damage to a blood clot. The amount of damage to the fiber network caused by a single bubble expansion and collapse is estimated by two independent approaches: One based on the stretch of individual fibers and the other based on the energy available to break individual fibers. The two methods yield consistent results. The energy method is extended to the more important scenario of a bubble outside a blood clot that collapses asymmetrically creating an impinging jet. This leads to significantly more damage compared to a bubble embedded within the clot structure. Finally, as an example of how one can apply the theory, a simulation of the propagation of HIFU waves through model calvaria of varying density is explored. The maximum amount of energy available to cause damage to a blood clot increases as the density of the calvaria decreases.
Electromechanical properties of stripe-electroded tangentially polarized piezoelectric flexural bars
Authors: Sarangapani Sairajan , Brown David A.
Published: May 2013

Piezoelectric bar transducers are commonly used for generating low frequency flexural mode vibrations. The paper calculates the electromechanical properties including the effective electromechanical coupling coefficient of the stripe-electroded tangentially polarized bar transducer vibrating in flexure under the simply supported boundary condition. A numerical analysis is used to model the curved electric field lines. Calculations take into account the internal energies due to the contributions of the transverse and longitudinal piezoelectric effects and the modal strain distribution in the bar. Results are presented as functions of distance between the electrodes and thickness of elements and are compared with traditional bimorph designs employing either transverse or longitudinal polarization.
Single-shot measurements of the acoustic field of an electrohydraulic lithotripter using a hydrophone array
Authors: Alibakhshi Mohammad A. , Kracht Jonathan M. , Cleveland Robin O. , Filoux Erwan , Ketterling Jeffrey A.
Published: May 2013

Piezopolymer-based hydrophone arrays consisting of 20 elements were fabricated and tested for use in measuring the acoustic field from a shock-wave lithotripter. The arrays were fabricated from piezopolymer films and were mounted in a housing to allow submersion into water. The motivation was to use the array to determine how the shot-to-shot variability of the spark discharge in an electrohydraulic lithotripter affects the resulting focused acoustic field. It was found that the dominant effect of shot-to-shot variability was to laterally shift the location of the focus by up to 5 mm from the nominal acoustic axis of the lithotripter. The effect was more pronounced when the spark discharge was initiated with higher voltages. The lateral beamwidth of individual, instantaneous shock waves were observed to range from 1.5 mm to 24 mm. Due to the spatial variation of the acoustic field, the average of instantaneous beamwidths were observed to be 1 to 2 mm narrower than beamwidths determined from traditional single-point measurements that average the pressure measured at each location before computing beamwidth.
Human sensitivity to differences in the rate of auditory cue change
Authors: Maloff Erin S. , Wesley Grantham D. , Ashmead Daniel H.
Published: May 2013

Measurement of sensitivity to differences in the rate of change of auditory signal parameters is complicated by confounds among duration, extent, and velocity of the changing signal. Dooley and Moore [(1988) J. Acoust. Soc. Am. 84(4), 1332–1337] proposed a method for measuring sensitivity to rate of change using a duration discrimination task. They reported improved duration discrimination when an additional intensity or frequency change cue was present. The current experiments were an attempt to use this method to measure sensitivity to the rate of change in intensity and spatial position. Experiment 1 investigated whether duration discrimination was enhanced when additional cues of rate of intensity change, rate of spatial position change, or both were provided. Experiment 2 determined whether participant listening experience or the testing environment influenced duration discrimination task performance. Experiment 3 assessed whether duration discrimination could be used to measure sensitivity to rates of changes in intensity and spatial position for stimuli with lower rates of change, as well as emphasizing the constancy of the velocity cue. Results of these experiments showed that duration discrimination was impaired rather than enhanced by the additional velocity cues. The findings are discussed in terms of the demands of listening to concurrent changes along multiple auditory dimensions.
Toward a quantitative account of pitch distribution in spontaneous narrative: Method and validation
Authors: Matteson Samuel E. , Streit Olness Gloria , Caplow Nancy J.
Published: May 2013

Pitch is well-known both to animate human discourse and to convey meaning in communication. The study of the statistical population distributions of pitch in discourse will undoubtedly benefit from methodological improvements. The current investigation examines a method that parameterizes pitch in discourse as musical pitch interval H measured in units of cents and that disaggregates the sequence of peak word-pitches using tools employed in time-series analysis and digital signal processing. The investigators test the proposed methodology by its application to distributions in pitch interval of the peak word-pitch (collectively called the discourse gamut) that occur in simulated and actual spontaneous emotive narratives obtained from 17 middle-aged African-American adults. The analysis, in rigorous tests, not only faithfully reproduced simulated distributions imbedded in realistic time series that drift and include pitch breaks, but the protocol also reveals that the empirical distributions exhibit a common hidden structure when normalized to a slowly varying mode (called the gamut root) of their respective probability density functions. Quantitative differences between narratives reveal the speakers' relative propensity for the use of pitch levels corresponding to elevated degrees of a discourse gamut (the “e-la”) superimposed upon a continuum that conforms systematically to an asymmetric Laplace distribution.
The precedence effect: Fusion and lateralization measures for headphone stimuli lateralized by interaural time and level differences
Authors: Brown Andrew D. , Christopher Stecker G.
Published: May 2013

The present investigation assessed fusion and localization dominance aspects of the precedence effect under headphones across a variety of stimulus conditions in 10 normal-hearing listeners. Listeners were presented with “lead-lag” pairs of brief (123 μs) impulses or trains of such pairs lateralized by interaural time or level differences (ITD or ILD). Listeners used a touch-sensitive display to indicate for the final lead-lag pair presented on each trial (1) whether one or two locations were perceived and (2) the location perceived. In the event two locations were perceived, subjects were further instructed to indicate the left-most location perceived. Results demonstrated that lead-lag fusion was more robust for stimuli lateralized by ITD than ILD, particularly when cues of the test stimulus differed from cues of the preceding “buildup” stimulus, consistent with Krumbholz and Nobbe [(2002). J. Acoust. Soc. Am. 112, 654–663]. Unexpectedly, results also demonstrated reduced localization dominance with increasing lead-lag delay, suggesting that the fusion aspect of the precedence effect may be dissociated from the localization dominance aspect under buildup. It is thus argued that buildup of fusion might be understood more generally as an example of auditory object formation rather than a special facility for enhanced sound localization.
Modal decomposition of exterior acoustic-structure interaction
Authors: Peters Herwig , Kessissoglou Nicole , Marburg Steffen
Published: May 2013

A modal decomposition technique to analyze individual modal contributions to the sound power radiated from an externally excited structure submerged in a heavy fluid is presented. The fluid-loaded structural modes are calculated by means of a polynomial approximation and symmetric linearization of the underlying nonlinear eigenvalue problem. The eigenvalues and eigenfunctions of a fluid loaded sphere with and without internal structures are presented. The modal sound power contributions using both fluid-loaded structural modes and acoustic radiation modes are presented. The results for the resistive and reactive sound power obtained from the superposition of the individual modal sound power contributions are compared to the harmonic solution of the forced problem.
Experimental verification of transient nonlinear acoustical holography
Authors: Jing Yun , Cannata Jonathan , Wang Tianren
Published: May 2013

This paper presents an experimental study on nonlinear transient acoustical holography. The validity and effectiveness of a recently proposed nonlinear transient acoustical holography algorithm is evaluated in the presence of noise. The acoustic field measured on a post-focal plane of a high-intensity focused transducer is backward projected to reconstruct the pressure distributions on the focal and a pre-focal plane, which are shown to be in good agreement with the measurement. In contrast, the conventional linear holography produces erroneous results in this case where the nonlinearity involved is strong. Forward acoustic field projection was also carried out to further verify the algorithm.
The role of binary mask patterns in automatic speech recognition in background noise
Authors: Narayanan Arun , Wang DeLiang
Published: May 2013

Processing noisy signals using the ideal binary mask improves automatic speech recognition (ASR) performance. This paper presents the first study that investigates the role of binary mask patterns in ASR under various noises, signal-to-noise ratios (SNRs), and vocabulary sizes. Binary masks are computed either by comparing the SNR within a time-frequency unit of a mixture signal with a local criterion (LC), or by comparing the local target energy with the long-term average spectral energy of speech. ASR results show that (1) akin to human speech recognition, binary masking significantly improves ASR performance even when the SNR is as low as −60 dB; (2) the ASR performance profiles are qualitatively similar to those obtained in human intelligibility experiments; (3) the difference between the LC and mixture SNR is more correlated to the recognition accuracy than LC; (4) LC at which the performance peaks is lower than 0 dB, which is the threshold that maximizes the SNR gain of processed signals. This broad agreement with human performance is rather surprising. The results also indicate that maximizing the SNR gain is probably not an appropriate goal for improving either human or machine recognition of noisy speech.
The interpretation of speech reception threshold data in normal-hearing and hearing-impaired listeners: II. Fluctuating noise
Authors: Smits Cas , Festen Joost M.
Published: May 2013

Following previous work [Smits and Festen. (2011). J. Acoust. Soc. Am. 130, 2987–2998] involving the interpretation of speech reception threshold (SRT) data in steady-state noise, the present study considers fluctuating noise. Whereas the SIIsteady function [i.e., the speech intelligibility index (SII) against SNR in steady-state noise] can be approximated by a simple linear function going from 0 to 1 between SNR = −15 dB to +15 dB, the SIIfluc function is a function over a broader range than 30 dB and its maximum lies at a SNR higher than +15 dB. The difference in shape between the SIIsteady and SIIfluc functions has several implications. It predicts a reduction in fluctuating masker benefit (FMB), or even a negative FMB, for higher SNRs for normal-hearing listeners. Experimental data confirm this prediction. Much of the reduction in FMB for hearing-impaired listeners may be attributed to the higher SRTs in steady-state noise for these listeners.
Experimental methods for the characterization of the frequency-dependent viscoelastic properties of soft materials
Authors: Kazemirad Siavash , K. Heris Hossein , Mongeau Luc
Published: May 2013

A characterization method based on Rayleigh wave propagation was developed for the quantification of the frequency-dependent viscoelastic properties of soft materials at high frequencies; i.e., up to 4 kHz. Planar harmonic surface waves were produced on the surface of silicone rubber samples. The phase and amplitude of the propagating waves were measured at different locations along the propagation direction, which allowed the calculation of the complex Rayleigh wavenumbers at each excitation frequency using a transfer function method. An inverse wave propagation problem was then solved to obtain the complex shear/elastic moduli from the measured wavenumbers. In a separate, related investigation, dynamic indentation tests using atomic force microscopy (AFM) were performed at frequencies up to 300 Hz. No systematic verification study is available for the AFM-based method, which can be used when the dimensions of the test samples are too small for other existing testing methods. The results obtained from the Rayleigh wave propagation and AFM-based indentation methods were compared with those from a well-established method, which involves the generation of standing longitudinal compression waves in rod-shaped test specimens. The results were cross validated and qualitatively confirmed theoretical expectations presented in the literature for the frequency-dependence of polymers.
Metrics for vector quantization-based parametric speech enhancement and separation
Authors: Christensen Mads Græsbøll
Published: May 2013

Speech enhancement and separation algorithms sometimes employ a two-stage processing scheme, wherein the signal is first mapped to an intermediate low-dimensional parametric description after which the parameters are mapped to vectors in codebooks trained on, for example, individual noise-free sources using a vector quantizer. To obtain accurate parameters, one must employ a good estimator in finding the parameters of the intermediate representation, like a maximum likelihood estimator. This leaves some unanswered questions, however, like what metrics to use in the subsequent vector quantization process and how to systematically derive them. This paper aims at answering these questions. Metrics for this are presented and derived, and their use is exemplified on a number of different signal models by deriving closed-form expressions. The metrics essentially take into account in the vector quantization process that some parameters may have been estimated more accurately than others and that there may be dependencies between the estimation errors.
Dynamic surface acoustic response to a thermal expansion source on an anisotropic half space
Authors: Zhao Peng , Zhao Ji-Cheng , Weaver Richard
Published: May 2013

The surface displacement response to a distributed thermal expansion source is solved using the reciprocity principle. By convolving the strain Green's function with the thermal stress field created by an ultrafast laser illumination, the complete surface displacement on an anisotropic half space induced by laser absorption is calculated in the time domain. This solution applies to the near field surface displacement due to pulse laser absorption. The solution is validated by performing ultrafast laser pump-probe measurements and showing very good agreement between the measured time-dependent probe beam deflection and the computed surface displacement.
Coarse-grid computation of the one-way propagation of coupled modes in a varying cross-section waveguide
Authors: Doc Jean-Baptiste , Félix Simon , Lihoreau Bertrand
Published: May 2013

A one-way approximation is investigated for the computation of wave propagation in varying cross-section waveguides. The proposed method derives as a basic approximation of the extensively studied multimodal admittance method. When integrated with a Magnus scheme, this matrix one-way equation exhibits an unexpected behavior, as the deviation from the exact solution is minimum when only two discretization points per wavelength are taken. This peculiar property makes this method efficient to compute the wave propagation for a large variety of geometries, beyond the initially stated framework of weakly non-uniform waveguides.
Sound source localization of filtered noises by listeners with normal hearing: A statistical analysis
Authors: Yost William A. , Loiselle Louise , Dorman Michael , Burns Jason , Brown Christopher A.
Published: May 2013

Several measures of sound source localization performance of 45 listeners with normal hearing were obtained when loudspeakers were in the front hemifield. Localization performance was not statistically affected by filtering the 200-ms, 2-octave or wider noise bursts (125 to 500, 1500 to 6000, and 125 to 6000 Hz wide noise bursts). This implies that sound source localization performance for noise stimuli is not differentially affected by which interaural cue (interaural time or level difference) a listener with normal hearing uses for sound source localization, at least for relatively broadband signals. This sound source localization task suggests that listeners with normal hearing perform with high reliability/repeatability, little response bias, and with performance measures that are normally distributed with a mean root-mean-square error of 6.2° and a standard deviation of 1.79°.
Sparse recovery of the multimodal and dispersive characteristics of Lamb waves
Authors: Harley Joel B. , Moura José M. F.
Published: May 2013

Guided waves in plates, known as Lamb waves, are characterized by complex, multimodal, and frequency dispersive wave propagation, which distort signals and make their analysis difficult. Estimating these multimodal and dispersive characteristics from experimental data becomes a difficult, underdetermined inverse problem. To accurately and robustly recover these multimodal and dispersive properties, this paper presents a methodology referred to as sparse wavenumber analysis based on sparse recovery methods. By utilizing a general model for Lamb waves, waves propagating in a plate structure, and robust ℓ1 optimization strategies, sparse wavenumber analysis accurately recovers the Lamb wave's frequency-wavenumber representation with a limited number of surface mounted transducers. This is demonstrated with both simulated and experimental data in the presence of multipath reflections. With accurate frequency-wavenumber representations, sparse wavenumber synthesis is then used to accurately remove multipath interference in each measurement and predict the responses between arbitrary points on a plate.
ACOUSTICAL STANDARDS NEWS
Authors: Blaeser Susan B. , Schomer Paul D.
Published: May 2013

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes catalogs of Acoustical Standards, both National and International. To receive copies of the latest Standards catalogs, please contact Susan B. Blaeser.

Comments are welcomed on all material in Acoustical Standards News.

This Acoustical Standards News section in JASA, as well as the National and International Catalogs of Acoustical Standards, and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org.
Room acoustic transition time based on reflection overlap
Authors: Jeong Cheol Ho , Brunskog Jonas , Jacobsen Finn
Published: May 2013

A transition time is defined based on the temporal overlap of reflected pulses in room impulse responses. Assuming specular reflections only, the temporal distance between adjacent reflections, which is proportional to the volume of a room, is compared with the characteristic width of a pulse at time t, which is mainly controlled by the absorption characteristics of the boundary surfaces of the room. Scattering, diffuse reflections, and diffraction, which facilitate the overlapping process, have not been taken into account. Measured impulse responses show that the transition occurs earlier in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions.
The influence of noise on monaural room acoustic parameters utilizing different evaluation methods
Authors: Guski Martin , Vorländer Michael
Published: May 2013

Besides clarity and definition, the reverberation time is the most common room acoustic parameter. The latter is also an essential quantity for acoustic measuring techniques (i.e., sound insulation, scattering, or diffuse absorption). The unavoidable occurring noise in every measurement is the most significant factor that causes incorrect evaluated parameters. Therefore, it is important to respond to the effects caused by noise. In this study, different noise compensation methods are compared theoretically and based on measurements. At first all methods are investigated theoretically utilizing a simple parametric model impulse response. As a second step, long-term measurements have been conducted in an auditorium to analyze the performance of the different techniques under realistic conditions. Therefore, the excitation signal has been varied in volume to obtain measurements with different noise levels, and the evaluated room acoustic parameters are examined as a function of peak-signal to noise ratio. Theoretical and measured results coincide with each other for each analyzed method. The performances of the examined evaluation methods differ clearly. In particular, the three methods defined by ISO 3382 show different behaviors. The advantages and the limitations of each noise compensation method are presented.
Including directivity patterns in room acoustical measurements
Authors: Pollow Martin , Klein Johannes , Dietrich Pascal , Vorländer Michael
Published: May 2013

Room acoustical measurements according to ISO 3382 require source and receiver to be of omnidirectional sensitivity. Therefore, radiation patterns of natural sources and receivers (although audible) are not accounted for when using the obtained room impulse responses (RIRs) for room acoustic analysis or even auralization. In order to include this spatial information in the RIR, it is necessary to measure the RIR for each pair of radiation patterns of source and receiver. This could be done by electronic beamforming during the measurement using array systems or by mechanical modification of the transducer (as, e.g., a dummy-head with its corpus). In this contribution, an alternative approach is shown, using the superposition of a set of sequential measurements done with a spherical sound source. At the cost of longer measurement times, the obtained data can be used universally to synthesize RIRs of arbitrary directivity up to a certain maximal spatial resolution, as long as the room is considered as a linear and time-invariant system during the measurement. The measurement device, obtained results, and a study of the validity of the superposition approach are presented in this talk. Based on this representation of the RIR, more advanced spatial room acoustic analysis accounting for arbitrary sets of source and receiver directivity becomes possible.
Achieving the acoustical credit within the Leadership in Energy and Environmental Design (LEED®) for healthcare green building rating system and changes within the forthcoming 2014 Guidelines
Authors: Horan Daniel M. , Latour Jean-François
Published: May 2013

The 2009 LEED® for Healthcare green building rating system includes a total of two possible points to be earned by satisfying the requirements of the Indoor Environmental Quality Credit 2 (IEQ Credit 2: Acoustic Environment). This credit references criteria that are defined by the Facility Guidelines Institute's 2010 Guidelines for Design and Construction of Health Care Facilities (2010 FGI Guidelines). The acoustical design requirements of the 2010 FGI Guidelines will be summarized, as well as a brief history of the FGI document itself. The FGI Guidelines document is currently being revised for the 2014 edition. Proposed changes in the 2014 edition will also be briefly discussed, as we anticipate that future versions of the LEED® rating system will reference the 2014 FGI Guidelines. The presentation will be made in English by Mr. Horan, secretary of the FGI's Acoustical Working Group (AWG). Mr. Latour, a French-Canadian member of the AWG, will be available to help respond to any French-speaking audience members during Q&A.
Development of an ecological, smooth, unperforated sound absorptive material
Authors: Karabulut Seda , Çalışkan Mehmet
Published: May 2013

Material selection for acoustically comfortable environments is a very important issue especially for rooms for speech and music as well as for large volumes like shopping centers and foyers. Energy efficient and sustainable materials are devised in construction industry for healthy environments; hence, ecological sound absorbing materials for acoustically sensitive environments are being preferred to get credits for international certification procedures like LEED and BREAM. Nevertheless, most of the acoustic materials in construction industry are perforated with mineral wool based absorption materials behind and have great effects on design of the building environments. Architects usually prefer seamless unperforated materials to avoid changes in the appearance of design environments for acoustical requirements. This article is about development of an ecological unperforated acoustical material, which is made of reed and pumice stone. Different layers of pumice stone and reed glued with an ecological binder are evaluated according to frequency range they are effective, and an optimization is done to create an acoustic material that is effective especially in medium frequencies. Acoustical performance of the material is justified with measurements of sound absorption coefficient in Kundt Tube.