bluuebunny/crossref_metadata_2025 huggingface dataset:
ORIGINAL ARTICLE: An Interleukin‐23 Binding Protein in Mid‐Trimester Amniotic Fluid
Authors: Herway Catherine , Bongiovanni Ann Marie , Skupski Daniel , Witkin Steven S.
Published: October 2009

Problem  The binding of mid‐trimester amniotic fluid to cytokines was evaluated.

Method of study  Purified tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐10, IL‐12, and IL‐23 were incubated with amniotic fluid from 25 women undergoing a mid‐trimester amniocentesis, or with bovine serum albumin or saline, and cytokine binding to monoclonal antibodies was quantitated by ELISA. Aliquots of amniotic fluid were heated to 95°C for 15 min and then retested for IL‐23 binding. The effect of amniotic fluid dilution on IL‐23 quantitation was evaluated.

Results  All amniotic fluids had a negligible effect on TNF‐α, IL‐10, and IL‐12 detection. In marked contrast, pre‐incubation with amniotic fluid from each subject reduced the subsequent ability to detect IL‐23 by >50%. The extent of inhibition was directly proportional to the amniotic fluid dilution and was markedly reduced following heating at 95°C for 15 min. Amniotic fluids from White, Black, Asian, East Indian, and Hispanic women were equally effective.

Conclusion  Interleukin‐23 and IL‐12 share a common p40 subunit and no inhibition of IL‐12 was apparent. It appeared that a component of mid‐trimester amniotic fluid specifically interacts with the p19 subunit unique to IL‐23. Mid‐trimester amniotic fluid reactivity with IL‐23 may be a mechanism to limit intra‐amniotic neutrophil‐derived inflammation.
ORIGINAL ARTICLE: Live Birth Rate According to Maternal Age and Previous Number of Recurrent Miscarriages
Authors: Sugiura‐Ogasawara Mayumi , Ozaki Yasuhiko , Kitaori Tamao , Suzumori Nobuhiro , Obayashi Shintaro , Suzuki Sadao
Published: October 2009

Problem  In Japan, marital age and women’s age at the first pregnancy are continuing to increase year by year. However, information concerning subsequent live birth rate according to maternal age and number of previous recurrent miscarriages is limited.

Method of study  We studied a total of 1250 unexplained patients suffering two or more consecutive miscarriages. We examined the live birth rate at the first pregnancy and the cumulative success rate for birth of at least one child after examination.

Results  The live birth rate of women in their 40s was 58.1%, which was similar to that of women who were 35–39 years old (58.4%) at the first pregnancy, as found after examination. From logistic regression, women’s age and the number of previous miscarriages independently decreased the live birth rate in subsequent pregnancies (ps) as well as cumulative pregnancies (pc), as follows:
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Conclusion  The information concerning the live birth rate can be given to each patient before subsequent pregnancy.
Contradictions in the treatment of traumatic dental injuries and ways to proceed in dental trauma research*
Authors: Andreasen Jens Ove , Lauridsen Eva , Andreasen Frances Meriam
Published: October 2009

Abstract –  Almost all treatment procedures used for dental traumas are still today not evidence‐based, a fact, which makes it difficult to analyse the long‐term outcome of healing and its relationship to treatment. Crown fractures with extensive dentin exposure represent a dominant injury in the permanent dentition. Accepted treatment philosophy is dentin coverage (dental liner and/or dentin bonded restoration) to prevent bacteria penetration into the pulp. Today there is, apart from deep proximal fractures, no evidence that this treatment is necessary to protect the pulp. In case of luxation injuries, the accepted treatment principles appear to be anatomically correct repositioning, stabilization with a splint and sometimes antibiotic coverage. In clinical studies, these principles could not be proven to optimize either periodontal or pulpal healing, the explanation possibly being that both reposition and application of splints in certain cases add extra damage to the pulp and periodontal ligament. In case of root fractures with dislocation, fast and optimal repositioning and rigid long‐term splinting (i.e. 3 months) have been considered the principle of treatment. However, a recent clinical study has shown that short‐term splinting with a semi‐rigid splint appears to optimize fracture healing. In tooth avulsion with subsequent replantation, cleansing of the root surface for contamination and systemic antibiotics has been considered essential for pulp and periodontal healing. These treatment concepts have been derived from experimental studies in animals. However, their importance could not be verified in large clinical studies. Ideally, randomized clinical studies are needed in the future for selected trauma types. The influences of repositioning, splinting and the role of infection and antibiotics should be further investigated. However, for ethical reasons, it will be difficult to perform randomized studies on trauma victims and we will be forced in the future to rely on experimental animal studies supported by clinical observational studies.
THE BORDER CROSSED US: EDUCATION, HOSPITALITY POLITICS, AND THE SOCIAL CONSTRUCTION OF THE “ILLEGAL IMMIGRANT”
Authors: Carlson Dennis
Published: October 2009

Abstract

In this essay, Dennis Carlson explores some of the implications of Derrida's “hospitality politics” in helping articulate a progressive response to a rightist cultural politics in the United States of policing national, linguistic, and other borders. He applies the concept of hospitality politics to a critical analysis of the social construction of the “problem” of “illegal immigrants” in U.S. public schools. This entails a discussion of three interrelated discourses and practices of hospitality: a universalistic discourse of philosophical and religious principles, a legalistic‐juridical discourse, and a discourse and practice grounded in the ethos of everyday life. Derrida suggested that a democratic cultural politics must interweave these three discourses and also recognize the limitations of each of them. Moreover, a democratic cultural politics must be most firmly rooted in the praxis of ethos, and in the ethical claims of openness to the other.
A Clinical Review of Infected Wound Treatment with Vacuum Assisted Closure® (V.A.C.®) Therapy: Experience and Case Series
Authors: Gabriel Allen , Shores Jaimie , Bernstein Brent , De Leon Jean , Kamepalli Ravi , Wolvos Tom , Baharestani Mona M , Gupta Subhas
Published: October 2009

Over the last decade Vacuum Assisted Closure® (KCI Licensing, Inc., San Antonio, TX) has been established as an effective wound care modality for managing complex acute and chronic wounds. The therapy has been widely adopted by many institutions to treat a variety of wound types. Increasingly, the therapy is being used to manage infected and critically colonized, difficult‐to‐treat wounds. This growing interest coupled with practitioner uncertainty in using the therapy in the presence of infection prompted the convening of an interprofessional expert advisory panel to determine appropriate use of the different modalities of negative pressure wound therapy (NPWT) as delivered by V.A.C.® Therapy and V.A.C. Instill® with either GranuFoam™ or GranuFoam Silver™ Dressings. The panel reviewed infected wound treatment methods within the context of evidence‐based medicine coupled with experiential insight using V.A.C.® Therapy Systems to manage a variety of infected wounds. The primary objectives of the panel were 1) to exchange state‐of‐practice evidence, 2) to review and evaluate the strength of existing data, and 3) to develop practice recommendations based on published evidence and clinical experience regarding use of the V.A.C.® Therapy Systems in infected wounds. These recommendations are meant to identify which infected wounds will benefit from the most appropriate V.A.C.® Therapy System modality and provide an infected wound treatment algorithm that may lead to a better understanding of optimal treatment strategies.
Endodontic management of a fused mandibular third molar and distomolar: A case report
Authors: Zeylabi Ali , Shirani Farzaneh , Heidari Fatemeh , Farhad Ali Reza
Published: October 2009

Careful management of fused teeth is essential as abnormal morphology can predispose a tooth to caries and periodontal disease. In this paper, a rare case of successful endodontic management of unilateral mandibular third molar fused to a distomolar is reported. Caries was removed from the tooth complex under local anaesthesia. The pulp chambers of the third molar and supernumerary tooth were accessed and the root canals were prepared using rotary instrumentation and copious irrigation with 2.5% sodium hypochlorite. Obturation using the lateral condensation technique with gutta‐percha and AH26 sealer was subsequently performed. A 1‐year recall showed a good treatment result.
The impact of climate change on reservoir water quality and water treatment plant operations: a UK case study
Authors: Thorne O. , Fenner R. A.
Published: October 2009

A simplified climate change impact assessment tool (SCIAT) has been developed to address the specific needs of the water industry and provides a tool to translate climate change projections into ‘real world’ impacts. Its application is demonstrated in this study to assess the impacts of climate change on the reservoir water quality and water treatment plant (WTP) operations at Grafham Water in the east of England. The primary aim is to provide WTP operators with knowledge of the potential impacts and associated probabilities of occurrence of climate change, enabling them to make informed, risk‐based adaptation and planning decisions. Using a series of coupled hydrological and water‐quality models, it is likely that there will be a decline in average reservoir water quality. Climate change will also have an impact on WTP operations, but these will be manageable within the current operational parameters.
Effect of irrigation water benefit on energy production in a multiple reservoir system: the Munzur River Basin in Turkey
Authors: Opan M. , Temiz T. , Öner A.
Published: October 2009

In this study, a water resource system with multi‐objective and multiple reservoirs is formulated mathematically. An optimization model for long‐term planning, taking into consideration irrigation water and firm power in the parametric variable approach, is established using this system. The optimization technique of dynamic programming with successive approximations (DPSA) is used in the optimization process. In the optimization model, firstly, by using the monthly means inflow data of the drought period and changing irrigation water parametrically, firm power values are maximized. Then, in the same model, the total energy of the system is maximized by using the firm power values obtained as a parametric constant and the data of the monthly average flow. The model is applied to a water resource system with multiple reservoirs and multi‐objectives in the Munzur River Basin, Turkey. The results are evaluated with regard to irrigation water, energy production and total benefits.
A role for the volume regulated anion channel in volume regulation in the murine CNS cell line, CAD
Authors: Harvey V. L. , Saul M. W. , Garner C. , McDonald R. L.
Published: October 2009

Aim:  The role of the volume regulated anion channel (VRAC) in a model CNS neuronal cell line, CAD, was investigated.

Methods:  Changes in cell volume following hypotonic challenges were measured using a video‐imaging technique. The effect of the Cl− channel antagonists tamoxifen (10 μm) and 4,4′‐diisothiocyanatostilbene‐2,2′‐disulphonic acid (DIDS; 100 μm) on regulatory volume decrease (RVD) were measured. The whole‐cell voltage‐clamp technique was used to characterize IClswell, the current underlying the VRAC.

Results:  Using the video‐imaging technique, CAD cells were found to swell and subsequently exhibit RVD when subjected to a sustained hypotonic challenge from 300 mOsmol kg−1 H2O to 210 mOsmol kg−1 H2O. In the presence of tamoxifen (10 μm) or DIDS (100 μm) RVD was abolished, suggesting a role for the VRAC. A hypotonic solution (230 mOsmol kg−1 H2O) evoked IClswell, an outwardly rectifying current displaying time‐independent activation, which reversed upon return to isotonic conditions. The reversal potential (Erev) for IClswell was −14.7 ± 1.4 mV, similar to the theoretical Erev for a selective Cl− conductance. IClswell was inhibited in the presence of DIDS (100 μm) and tamoxifen (10 μm), the DIDS inhibition being voltage dependent.

Conclusions:  Osmotic swelling elicits an outwardly rectifying Cl− conductance in CAD cells. The IClswell observed in these cells is similar to that observed in other cells, and is likely to provide a pathway for the loss of Cl− which leads to water loss and RVD. As ischaemia, brain trauma, hypoxia and other brain pathologies can cause cell swelling, CAD cells represent a model cell line for the study of neuronal cell volume regulation.
Physiological and transcriptomic characterization of a fliA mutant of Pseudomonas putida KT2440
Authors: Rodríguez‐Herva José Juan , Duque Estrella , Molina‐Henares María Antonia , Navarro‐Avilés Gloria , Van Dillewijn Pieter , De La Torre Jesús , Molina‐Henares Antonio J. , La Campa Ana Sánchez‐de , Ran F. Ann , Segura Ana , Shingler Victoria , Ramos Juan‐Luis
Published: October 2009

Pseudomonas putida KT2440 encodes 23 alternative sigma factors. The fliA gene, which encodes σ28, is in a cluster with other genes involved in flagella biosynthesis and chemotaxis. Reverse transcriptase‐PCR revealed that this cluster is comprised of four independent transcriptional units: flhAF, fleNfliA, cheYZA and cheBmotAB. We generated a nonpolar fliA mutant by homologous recombination and tested its motility, adhesion to biotic and abiotic surfaces, and responses to various stress conditions. The mutant strain was nonmotile and exhibited decreased capacity to bind to corn seeds, although its ability to colonize the rhizosphere of plants was unaffected. The mutant was also affected in binding to abiotic surfaces and its ability to form biofilms decreased by almost threefold. In the fliA mutant background expression of 25 genes was affected: two genes were upregulated and 23 genes were downregulated. In addition to a number of motility and chemotaxis genes, the fliA gene product is also necessary for the expression of some genes potentially involved in amino acid utilization or stress responses; however, we were unable to assign specific phenotypes linked to these genes since the fliA mutant used the same range of amino acids as the parental strain, and was as tolerant as the wild type to stress imposed by heat, antibiotics, NaCl, sodium dodecyl sulfate, H2O2 and benzoate. Based on the sequence alignment of promoters recognized by FliA and genome in silico analysis, we propose that P. putidaσ28 recognizes a TCAAG‐t‐N12‐GCCGATA consensus sequence located between −34 and −8 and that this sequence is preferentially associated with an AT‐rich upstream region.
Displaced Basal Coronoid Fracture and Fixation in a 7 Year Old: A Case Report and Review of the Literature
Authors: Arnold Ryan M. , Fehringer Edward V.
Published: October 2009

We present the delayed presentation, treatment, and outcome of a 7 year old male with a rare paediatric displaced basal coronoid fracture.
Screening of antenatal depression in Pakistan: risk factors and effects on obstetric and neonatal outcomes
Authors: Imran Nazish , Haider Imran Ijaz
Published: October 2009

Introduction: To determine the frequency of probable antenatal depression (AD) in pregnant women in third trimester, assess the risk factors and its impact on obstetric and neonatal outcomes in a developing country.

Methods: A prospective study conducted in a tertiary care hospital in Lahore from March 2007 to July 2007. Two hundred and thirteen pregnant women in the third trimester, attending the Gynecology Outpatient Clinic were recruited. They were assessed by a semistructured questionnaire to gather demographic details and various risk factors for AD. AD was assessed by Edinburgh Postnatal Depression Scale. All women were followed until delivery to determine their obstetric and neonatal outcomes.

Results: Out of 213 women, 91 (42.7%) scored above the cut‐off for AD. More women with depression reported problems in their marriage, problems with parents/in laws, history of domestic violence, past history of psychiatric problems and history of postnatal depression. In the obstetric risk factors history of previous miscarriages, stillbirths, and complications in previous pregnancy reached statistical significance. Thirty‐seven (17.3%) women were lost to follow up. Women with AD had more obstetric complications during delivery. Babies of mothers with AD had significantly low birth weight, as well as low mean APGAR scores at 1 and 5 minutes following birth.

Discussion: AD is a common problem in Pakistani Society. In view of the risk factors and adverse outcomes associated with depression during pregnancy, there is need for close liaison between Gynaecologists and Psychiatrists in managing these patients.
Effects of Prestrain With Strain Gradient Present on Sheet Metal Formability
Authors: Shang H. M. , Tan G. S. , Tan W. C. M.
Published: October 2009

In this investigation, two double-stage forming processes are used to study the effects of prestrain on sheet metal formability. The processes chosen are the bulge test and the plunger test using a die throat to punch diameter ratio of 2.42. It is seen that during the second stage of forming, deformation and shape of the deformed shell are influenced by the level of prestrain and strain gradients on the prestrained workpiece. An improved formability is observed when the workpiece for the plunger test is prestrained by hydroforming, but the formability is reduced when the prestraining process becomes the plunger test. The present results also imply that care should be taken in utilizing the forming limit diagram even if it is constructed from double-stage forming, in which strain gradient on the prestrained workpiece is generally absent.
An Experimental Study of the Structure of Constitutive Equations for Nonproportional Cyclic Plasticity
Authors: McDowell D. L.
Published: October 2009

Three type 304 stainless steel specimens of the same geometry were subjected to complex, cyclic axial-torsional histories characterized by varying degrees of non-proportionality of straining. All tests were at room-temperature. The data from cyclically stable hysteresis loops were reduced and the direction of the plastic strain rate vector, variation of plastic hardening modulus, and direction of translation of a rate and time-independent yield surface were studied. It is shown that the independent variables in a Mroz-type formulation map the experimental results with a higher degree of uniqueness than other popular formulations studied for both the hardening modulus and direction of yield surface translation. Also, the plastic strain rate is not, in general, in the direction of the deviatoric stress or stress rate.
Fracture Toughness of Irradiated HT-9 Weld Metal
Authors: Huang F. H. , Gelles D. S.
Published: October 2009

Fracture toughness tests were performed at 93, 205, 316, and 427°C using electropotential techniques on HT-9 weld material irradiated to a fluence of 2.35 × 1022 n/cm2 (E>0.1 MeV) at 390°C. Testing of welds irradiated at 450, 500, and 550°C was performed at 205°C. Test results were analyzed using the J-integral approach. It was found that the initiation fracture toughness of these HT-9 welds increased slightly, while the tearing modulus decreased significantly after irradiation to a fluence of 2.35 × 1022 n/cm2. In addition, results showed that irradiation temperature had little effect on the initiation fracture toughness of HT-9 weld metal. The specimens were examined by scanning electron microscopy after the test in order to understand the fracture process in this weld material.
A Study on Fatigue Life Distribution of Butt-Welded Joints
Authors: Sakai T. , Kikuchi T. , Tanaka T. , Fujitani K.
Published: October 2009

To examine the statistical fatigue life properties of welded joints, fatigue tests were performed on a number of butt-welded specimens, in parallel with similar tests conducted on small specimens spliced from larger butt-welded plates. Based on a statistical test, it was concluded that the distribution characteristics of crack initiation life for the butt-welded joint were successfully evaluated by the results for the spliced specimens for a certain definition of the crack initiation. The definition of crack initiation was based on a fracture mechanics similitute approach.
Auditory stream segregation in cochlear implant listeners: Measures based on temporal discrimination and interleaved melody recognition
Authors: Cooper Huw R. , Roberts Brian
Published: October 2009

The evidence that cochlear implant listeners routinely experience stream segregation is limited and equivocal. Streaming in these listeners was explored using tone sequences matched to the center frequencies of the implant’s 22 electrodes. Experiment 1 measured temporal discrimination for short (ABA triplet) and longer (12 AB cycles) sequences (tone/silence durations = 60/40 ms). Tone A stimulated electrode 11; tone B stimulated one of 14 electrodes. On each trial, one sequence remained isochronous, and tone B was delayed in the other; listeners had to identify the anisochronous interval. The delay was introduced in the second half of the longer sequences. Prior build-up of streaming should cause thresholds to rise more steeply with increasing electrode separation, but no interaction with sequence length was found. Experiment 2 required listeners to identify which of two target sequences was present when interleaved with distractors (tone/silence durations = 120/80 ms). Accuracy was high for isolated targets, but most listeners performed near chance when loudness-matched distractors were added, even when remote from the target. Only a substantial reduction in distractor level improved performance, and this effect did not interact with target-distractor separation. These results indicate that implantees often do not achieve stream segregation, even in relatively unchallenging tasks.
Acoustic mode radiation from the termination of a truncated nonlinear internal gravity wave duct in a shallow ocean area
Authors: Lin Ying-Tsong , Duda Timothy F. , Lynch James F.
Published: October 2009

Horizontal ducting of sound between short-wavelength nonlinear internal gravity waves in coastal environments has been reported in many theoretical and experimental studies. Important consequences arising at the open end of an internal wave duct (the termination) are examined in this paper with three-dimensional normal mode theory and parabolic approximation modeling. For an acoustic source located in such a duct and sufficiently far from the termination, some of the propagating sound may exit the duct by penetrating the waves at high grazing angles, but a fair amount of the sound energy is still trapped in the duct and propagates toward the termination. Analysis here shows that the across-duct sound energy distribution at the termination is unique for each acoustic vertical mode, and as a result the sound radiating from the termination of the duct forms horizontal beams that are different for each mode. In addition to narrowband analysis, a broadband simulation is made for water depths of order 80m and propagation distances of 24km. Situations occur with one or more modes absent in the radiated field and with mode multipath in the impulse response. These are both consistent with field observations.
Relation between derived-band auditory brainstem response latencies and behavioral frequency selectivity
Authors: Strelcyk Olaf , Christoforidis Dimitrios , Dau Torsten
Published: October 2009

Derived-band click-evoked auditory brainstem responses (ABRs) were obtained for normal-hearing (NH) and sensorineurally hearing-impaired (HI) listeners. The latencies extracted from these responses, as a function of derived-band center frequency and click level, served as objective estimates of cochlear response times. For the same listeners, auditory-filter bandwidths at 2 kHz were estimated using a behavioral notched-noise masking paradigm. Generally, shorter derived-band latencies were observed for the HI than for the NH listeners. Only at low click sensation levels, prolonged latencies were obtained for some of the HI listeners. The behavioral auditory-filter bandwidths accounted for the across-listener variability in the ABR latencies: Cochlear response time decreased with increasing filter bandwidth, consistent with linear-system theory. The results link cochlear response time and frequency selectivity in human listeners and offer a window to better understand how hearing impairment affects the spatiotemporal cochlear response pattern.
Sound pressure and particle acceleration audiograms in three marine fish species from the Adriatic Sea
Authors: Wysocki Lidia Eva , Codarin Antonio , Ladich Friedrich , Picciulin Marta
Published: October 2009

Fishes show great variability in hearing sensitivity, bandwidth, and the appropriate stimulus component for the inner ear (particle motion or pressure). Here, hearing sensitivities in three vocal marine species belonging to different families were described in terms of sound pressure and particle acceleration. In particular, hearing sensitivity to tone bursts of varying frequencies were measured in the red-mouthed goby Gobius cruentatus, the Mediterranean damselfish Chromis chromis, and the brown meagre Sciaena umbra using the non-invasive auditory evoked potential-recording technique. Hearing thresholds were measured in terms of sound pressure level and particle acceleration level in the three Cartesian directions using a newly developed miniature pressure-acceleration sensor. The brown meagre showed the broadest hearing range (up to 3000Hz) and the best hearing sensitivity, both in terms of sound pressure and particle acceleration. The red-mouthed goby and the damselfish were less sensitive, with upper frequency limits of 700 and 600Hz, respectively. The low auditory thresholds and the large hearing bandwidth of S. umbra indicate that sound pressure may play a role in S. umbra’s hearing, even though pronounced connections between the swim bladder and the inner ears are lacking.
Perceived loudness of speech based on the characteristics of glottal excitation source
Authors: Seshadri Guruprasad , Yegnanarayana B.
Published: October 2009

The impulse-like characteristic of glottal excitation in speech production is an important factor in the perception of loudness of speech signals. This characteristic is attributed to the abruptness of the closing phase in the glottal cycle. In this paper, an acoustic feature, called strength of excitation, is proposed to represent the impulse-like nature of excitation. The strength of excitation is derived from the linear prediction residual of speech signals, where the residual can be considered as an estimate of the source of excitation. Since the loudness of speech is perceived over one or more utterances of speech, it is hypothesized that the distribution of strength of excitation is indicative of the perceived loudness of speech. The distribution of strength of excitation is shown to distinguish between soft and loud utterances of speakers. The distribution can also help in discriminating between the loudness of two speakers. The loudness measure obtained using the distribution of the strength of excitation is in agreement with the subjective judgment of loudness of speech.
Note types and coding in Parid vocalizations: The chick-a-dee call of the chestnut-backed chickadee (Poecile rufuscens)
Authors: Hoeschele Marisa , Gammon David E. , Moscicki Michele K. , Sturdy Christopher B.
Published: October 2009

A first step to understanding how a species communicates acoustically is to identify, categorize, and quantify the acoustic parameters of the elements that make up their vocalizations. The “chick-a-dee” call notes of the chestnut-backed chickadee (Poecile rufescens) were sorted into four call note categories, A, C, D, and Dh notes, based on their acoustic structure as observed in sound spectrograms, and evaluated based on the syntactical ordering of the note types within calls. The notes were then analyzed using quantitative measures and it was determined which features have the potential to convey information to discriminate note type, individual, and the geographic origin of the producer. The findings were comparable to previous research of congeners in that chestnut-backed chickadee calls were produced with a relatively fixed syntax and contained similarly structured note types across all geographic regions. Overall this information will form a base for future research on chestnut-backed chickadee vocalizations and will strengthen the foundation for future comparative evolutionary studies.
Detection probability of vocalizing dugongs during playback of conspecific calls
Authors: Ichikawa Kotaro , Akamatsu Tomonari , Shinke Tomio , Sasamori Kotoe , Miyauchi Yukio , Abe Yuki , Adulyanukosol Kanjana , Arai Nobuaki
Published: October 2009

Dugongs (Dugong dugon) were monitored using simultaneous passive acoustic methods and visual observations in Thai waters during January 2008. Chirp and trill calls were detected by a towed stereo hydrophone array system. Two teams of experienced observers conducted standard visual observations on the same boat. Comparisons of detection probabilities of acoustic and visual monitoring between two independent observers were calculated. Acoustic and visual detection probabilities were 15.1% and 15.7%, respectively, employing a 300 s matching time interval. When conspecific chirp calls were broadcast from an underwater speaker deployed on the side of the observation boat, the detection probability of acoustic monitoring rose to 19.2%. The visual detection probability was 12.5%. Vocal hot spots characterized by frequent acoustic detection of calls were suggested by dispersion analysis, while dugongs were visually observed constantly throughout the focal area (p<0.001). Passive acoustic monitoring assisted the survey since detection performance similar to that of experienced visual observers was shown. Playback of conspecific chirps appeared to increase the detection probability, which could be beneficial for future field surveys using passive acoustics in order to ensure the attendance of dugongs in the focal area.
Estimating sound power radiated from rectangular baffled panels using a radiation factor
Authors: Palumbo Dan
Published: October 2009

A method is introduced which is shown to predict radiated sound power from rectangular baffled panels. The method employs a filtered wavenumber transform to extract the power in the supersonic wavenumbers on the panel and a radiation factor to scale the supersonic power to match the actual radiated sound power. Although empirically derived, the radiation factor is shown to be related to the radiation efficiency of an infinite panel. The radiation factor is simple, depending only on the ratio of the wavenumbers of the panel to the radiation medium, and the method is straightforward to use, requiring only the panel normal velocities. The computation is efficient, as much as two orders of magnitude faster than a Rayleigh integration, thus providing a means of combining sound power predictions with finite element optimizations. A formula is derived which predicts the lowest frequency for which the method is valid as a function of the bin width of the wavenumber transform. The radiation factor method is shown to produce radiated sound power estimates which favorably compare to estimates derived from intensity measurements of physical test specimens and to Rayleigh integral estimates computed using both simulated and measured velocities.
Hybrid method for determining the parameters of condenser microphones from measured membrane velocities and numerical calculations
Authors: Barrera-Figueroa Salvador , Rasmussen Knud , Jacobsen Finn
Published: October 2009

Typically, numerical calculations of the pressure, free-field, and random-incidence response of a condenser microphone are carried out on the basis of an assumed displacement distribution of the diaphragm of the microphone; the conventional assumption is that the displacement follows a Bessel function. This assumption is probably valid at frequencies below the resonance frequency. However, at higher frequencies the movement of the membrane is heavily coupled with the damping of the air film between membrane and backplate and with resonances in the back chamber of the microphone. A solution to this problem is to measure the velocity distribution of the membrane by means of a non-contact method, such as laser vibrometry. The measured velocity distribution can be used together with a numerical formulation such as the boundary element method for estimating the microphone response and other parameters, e.g., the acoustic center. In this work, such a hybrid method is presented and examined. The velocity distributions of a number of condenser microphones have been determined using a laser vibrometer, and these measured velocity distributions have been used for estimating microphone responses and other parameters. The agreement with experimental data is generally good. The method can be used as an alternative for validating the parameters of the microphones determined by classical calibration techniques.
Radiative transfer theory applied to ocean bottom modeling
Authors: Quijano Jorge E. , Zurk Lisa M.
Published: October 2009

Research on the propagation of acoustic waves in the ocean bottom sediment is of interest for active sonar applications such as target detection and remote sensing. The interaction of acoustic energy with the sea floor sublayers is usually modeled with techniques based on the full solution of the wave equation, which sometimes leads to mathematically intractable problems. An alternative way to model wave propagation in layered media containing random scatterers is the radiative transfer (RT) formulation, which is a well established technique in the electromagnetics community and is based on the principle of conservation of energy. In this paper, the RT equation is used to model the backscattering of acoustic energy from a layered elastic bottom sediment containing distributions of independent scatterers due to a constant single frequency excitation in the water column. It is shown that the RT formulation provides insight into the physical phenomena of scattering and conversion of energy between waves of different polarizations.
Octave-shifted pitch matching in nonword imitations: The effects of lexical stress and speech sound disorder
Authors: Peter Beate , Larkin Tara , Stoel-Gammon Carol
Published: October 2009

Perceptual similarities of musical tones separated by octave intervals are known as octave equivalence (OE). Peter et al. [(2008). Proceedings of the Fourth Conference on Speech Prosody, edited S. Maduerira, C. Reis, and P. Barbosa, Luso-Brazilian Association of Speech Sciences, Campinas, pp. 731–734] found evidence of octave-shifted pitch matching (OSPM) in children during verbal imitation tasks, implying OE in speech tokens. This study evaluated the role of lexical stress and speech sound disorder (SSD) in OSPM. Eleven children with SSD and 11 controls imitated low-pitched nonwords. Stimulus/response f0 ratios were computed. OSPM was expressed preferentially in stressed vowels. SSD was associated with reduced expression of OSPM in unstressed vowels only. Results are consistent with the psycholinguistic prominence of lexical stress and prosodic deficits in SSD.
Effects of external noise on detection of intensity increments
Authors: Jesteadt Walt , Schairer Kim S. , Nizami Lance , Khaddam Samar , Neely Stephen T.
Published: October 2009

The detection of an intensity increment in a longer duration sinusoid or pedestal is often used as a measure of intensity resolution, but the decision processes underlying this measure are poorly understood. Thresholds were obtained for detection of an increment in a 370-ms, 4-kHz pedestal in quiet or in noise to determine the relative contributions of background noise level and pedestal level, the effect of increment duration, and the effect of different noise spectra. Increment detection thresholds expressed in units of ΔL[10 log(1+ΔI/I)] decreased as pedestal levels increased. At low pedestal levels, increment detection was limited by the masking effect of the noise and was similar across noise conditions for pedestals of equal sensation level. At high pedestal levels, the noise had no effect and increment detection was determined by the pedestal level in dB SPL (sound pressure level). Increment detection improved with increasing increment duration and was altered less by a noise band above the pedestal/increment frequency than by a broadband noise that produced equal masking at the pedestal/increment frequency. The quadratic-compression model described by Neely and Jesteadt [(2005). Acta Acust. Acust. 91, 980–991] provided a better approximation to the data than a model based on excitation patterns.
A biomechanical model of cardinal vowel production: Muscle activations and the impact of gravity on tongue positioning
Authors: Buchaillard Stéphanie , Perrier Pascal , Payan Yohan
Published: October 2009

A three-dimensional (3D) biomechanical model of the tongue and the oral cavity, controlled by a functional model of muscle force generation (λ-model of the equilibrium point hypothesis) and coupled with an acoustic model, was exploited to study the activation of the tongue and mouth floor muscles during the production of French cardinal vowels. The selection of the motor commands to control the tongue and the mouth floor muscles was based on literature data, such as electromyographic, electropalatographic, and cineradiographic data. The tongue shapes were also compared to data obtained from the speaker used to build the model. 3D modeling offered the opportunity to investigate the role of the transversalis, in particular, its involvement in the production of high front vowels. It was found, with this model, to be indirect via reflex mechanisms due to the activation of surrounding muscles, not voluntary. For vowel /i/, local motor command variations for the main tongue muscles revealed a non-negligible modification of the alveolar groove in contradiction to the saturation effect hypothesis, due to the role of the anterior genioglossus. Finally, the impact of subject position (supine or upright) on the production of French cardinal vowels was explored and found to be negligible.
Acoustic absorption calculation in irreducible porous media: A unified computational approach
Authors: Lee Chang-Yong , Leamy Michael J. , Nadler Jason H.
Published: October 2009

A critical task in predicting and tailoring the acoustic absorption properties of porous media is the calculation of the frequency-dependent effective density and compressibility tensors, which are explicitly related to the micro-scale permeability properties. Although these two quantities exhibit strong sensitivity to physics occurring at complex micro-scale geometries, most of the existing literature focuses on employing very limited in-house and oftentimes multiple numerical analysis tools. In order to predict these parameters and acoustic absorption efficiently and conveniently, this article synthesizes multiple disparate approaches into a single unified formulation suitable for incorporation into a commercial analysis package. Numerical results computed herein for four close-packed porous media are compared to similar results available in the literature. These include simple cubic, body-centered cubic, and face-centered cubic structures, and also hexagonal close-packed, which has not appeared in the literature. Together with critical comparisons of a hybrid versus direct numerical approaches, the close agreement demonstrates the capabilities of the unified formulation to analyze and control the acoustic absorption properties at the microscopic level.
Sound radiation quantities arising from a resilient circular radiator
Authors: Aarts Ronald M. , Janssen Augustus J. E. M.
Published: October 2009

Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are either Stenzel functions (1−(σ∕a)2)n, with σ the radial coordinate on the radiator, or linear combinations of Zernike functions Pn(2(σ∕a)2−1), with Pn the Legendre polynomial of degree n. Both sets of functions give rise, via King’s integral for the pressure, to integrals for the quantities of interest involving the product of two Bessel functions. These integrals have a power series expansion and allow an expression in terms of Bessel functions of the first kind and Struve functions. Consequently, many of the results in [M. Greenspan, J. Acoust. Soc. Am. 65, 608–621 (1979)] are generalized and treated in a unified manner. A foreseen application is for loudspeakers. The relation between the radiated power in the near-field on one hand and in the far field on the other is highlighted.
Predicting the sound insulation of single leaf walls: Extension of Cremer’s model
Authors: Davy John L.
Published: October 2009

In his 1942 paper on the sound insulation of single leaf walls, Cremer [(1942). Akust. Z. 7, 81–104] made a number of approximations in order to show the general trend of sound insulation above the critical frequency. Cremer realized that these approximations limited the application of his theory to frequencies greater than twice the critical frequency. This paper removes most of Cremer’s approximations so that the revised theory can be used down to the critical frequency. The revised theory is used as a correction to the diffuse field limp panel mass law below the critical frequency by setting the nonexistent coincidence angle to 90°. The diffuse field limp panel mass law for a finite size wall is derived without recourse to a limiting angle by following the average diffuse field single sided radiation efficiency approach. The shear wave correction derived by Heckl and Donner [(1985). Rundfunktech Mitt. 29, 287–291] is applied to the revised theory in order to cover the case of thicker walls. The revised theory predicts the general trend of the experimental data, although the agreement is usually worse at low frequencies and depends on the value of damping loss factor used in the region of and above the critical frequency.
An evaluation of models for diotic and dichotic detection in reproducible noises
Authors: Davidson Sean A. , Gilkey Robert H. , Colburn H. Steven , Carney Laurel H.
Published: October 2009

Several psychophysical models for masked detection were evaluated using reproducible noises. The data were hit and false-alarm rates from three psychophysical studies of detection of 500-Hz tones in reproducible noise under diotic (N0S0) and dichotic (N0Sπ) conditions with four stimulus bandwidths (50, 100, 115, and 2900 Hz). Diotic data were best predicted by an energy-based multiple-detector model that linearly combined stimulus energies at the outputs of several critical-band filters. The tone-plus-noise trials in the dichotic data were best predicted by models that linearly combined either the average values or the standard deviations of interaural time and level differences; however, these models offered no predictions for noise-alone responses. The decision variables of more complicated temporal models, including the models of Dau et al. [(1996a). J. Acoust. Soc. Am. 99, 3615–3622] and Breebaart et al. [(2001a). J. Acoust. Soc. Am. 110, 1074–1088], were weakly correlated with subjects’ responses. Comparisons of the dependencies of each model on envelope and fine-structure cues to those in the data suggested that dependence upon both envelope and fine structure, as well as an interaction between them, is required to predict the detection results.
Channel separation of crosstalk cancellation systems with mismatched and misaligned sound sources
Authors: Qiu Xiaojun , Masiero Bruno , Vorländer Michael
Published: October 2009

Loudspeakers in virtual sound imaging systems are usually modeled as omnidirectional monopole sources. These models are, however, only an approximation for the low frequency range. This paper presents an analytical model of crosstalk cancellation systems in a free field which takes into account the scattering and spatial characteristics of the sound sources. Based on the proposed model, the effects caused by the spatial characteristics of the sound source and its misalignments on the performance of the crosstalk cancellation system are studied numerically. It is found that although the factors such as the directivity of the sound sources and the distance between the sound sources and receiver affect the performance of the system to a certain extent, the channel separation of the crosstalk cancellation system, however, is most sensitive to the misalignment of the subtended angle of the sound sources. Therefore, if highly accurate binaural cues are required in practical applications, the type and characteristics of the playback sound sources, their locations, and orientations all should be considered carefully.
On the sign of the adaptive passive fathometer impulse response
Authors: Traer James , Gerstoft Peter , Song H. C. , Hodgkiss William S.
Published: October 2009

Harrison [J. Acoust. Soc. Am. 125, 3511–3513 (2009)] presented a mathematical explanation for a sign-inversion induced to the passive fathometer response by minimum variance distortionless response (MVDR) beamforming. Here a concise mathematical formulation is offered, which decomposes the cross-spectral density matrix into coherent and incoherent components and allows the matrix inversion to be obtained exactly by eigendecomposition. This shows that, in the region containing the bottom reflection, the MVDR fathometer response is identical to that obtained with conventional processing multiplied by a negative factor.
The Experimental Media and Performing Arts Center (EMPAC) at Rensselaer Polytechnic: Defining, building, and using highest-quality spaces for hearing, seeing, and moving in space with integrated multi-modal media technology.
Authors: Goebel Johannes
Published: October 2009

This paper discusses studios and performance spaces built for multi-modal production, presentation, and research without compromises. Hearing, seeing, and moving in space were treated as equal in the definition of the physical properties of all spaces. Special diffusive acoustics were developed for a concert hall, a theater, and studios to be able to support any instrumental, vocal, or electronic sound from anywhere. The noise floor of the theater is as low as in the concert hall as in a studio used for video (NR 15). Only sine-wave dimmers are allowed. The integrated digital technology allows creating, recording, and projecting sound, images, and movement through thousands of audio channels, hundreds of high definition video channels, and with computer controlled rigging and flying. The world of the human senses is bridged with the digital world of technology. All noisy equipment is banned from any venue. All venues are acoustically extremely separated with one studio resting on springs, the other studio having a separate foundation, and acoustical joints everywhere. The team comprises artistic curators as well as engineers and researchers; artists and scholars are in residence; the task is to span arts, science, and technology. The center opened 2008.