bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral immunotherapy in hen’s egg‐allergic children increases a hypo‐proliferative subset of CD4+ T cells that could constitute a marker of tolerance achievement
Authors: Fuentes‐Aparicio Victoria , Alonso‐Lebrero Elena , Zapatero Lidia , Infante Sonsoles , Lorente Raquel , Ángeles Muñoz‐Fernández Ma , Correa‐Rocha Rafael
Published: July 2012

Background:  Food allergy affects a significant number of children and its prevalence, and persistence is undergoing an important increase in the last years. Specific oral tolerance induction (SOTI) is a promising therapy for food allergy. However, little is known about the immune mechanisms implicated in the desensitization to allergens. Our purpose was to study which immune parameters are modified during the process of tolerance achievement with the goal of identifying markers of tolerance induction.

Methods:  We performed an extensive immune analysis in 19 allergic children following SOTI with hen’s egg before and after the immunotherapy. Changes in lymphocyte subpopulations and serum cytokines were identified in children with desensitization achievement.

Results:  Sixteen children achieved complete tolerance to egg, and the immune analysis reveals that desensitization was accompanied in all the cases by a significant decrease in the percentage and absolute counts of effector‐memory CD4+ T cells (TEM) and a marked increase in the absolute counts of a subset of CD4+CD38+CD45RO− cells. Additionally, we also observed a marked reduction in the plasma levels of different Th1 and Th2 cytokines after tolerance achievement.

Conclusions:  Acquisition of tolerance in children after oral immunotherapy is accompanied by a decrease in the TEM population and the increase in a particular subset of CD4+ T cells with a hypo‐proliferative and non‐reactive phenotype. This hypo‐proliferative subset of cells could constitute a marker of the development of oral tolerance, and the study of this subset could contribute to the better understanding of the immune responses in allergic subjects.
Peanut seed storage proteins are responsible for clinical reactivity in Spanish peanut‐allergic children
Authors: Pedrosa María , Boyano‐Martínez Teresa , García‐Ara María Carmen , Caballero Teresa , Quirce Santiago
Published: July 2012

Background:  Seed storage proteins (SSP; Ara h 1, Ara h 2, Ara h 3) have been shown to be major peanut allergens, although recently, peanut lipid transfer protein has been reported to be an important allergen in the Mediterranean area. We sought to investigate the sensitization pattern to peanut SSP and vegetable pan‐allergens in a group of peanut‐allergic children compared with a peanut‐tolerant group.

Methods:  One hundred and twenty‐three children who presented with food allergy were included in the study. Tolerance to peanut ingestion was assessed. Specific IgE was determined by ImmunoCAP, and microarray ISAC was performed. Sensitization frequencies and levels of specific IgE were compared between groups.

Results:  Fifty‐five of 123 children presented symptoms upon contact or ingestion. Frequency of sensitization to Ara h 1, Ara h 2, and Ara h 3 was 60.0%, 72.7%, and 43.6%, respectively, in the group of allergic children vs. 7.4%, 1.5%, and 7.4% in the group of tolerant children. Levels of specific IgE against Ara h 1, Ara h 2, and Ara h 3 were significantly higher in the allergic group (p < 0.001). The frequency of sensitization and the levels of specific IgE against Cor a 8 (36.4% vs. 16.2%) were significantly higher in the allergic children, whereas no significant differences were found for Pru p 3. No differences were seen for other pan‐allergens. Patients sensitized to SSP, regardless of sensitization to nsLTP, were allergic rather than tolerant.

Conclusion:  In our population, peanut‐allergic children were mainly sensitive to SSP. A few patients were also sensitive to some nsLTPs. No differences were shown in other pan‐allergens.
Dual diagnosis, as described by those who experience the disorder: Using the Internet as a source of data
Authors: Edward Karen‐Leigh , Robins Alan
Published: July 2012

The complexity of providing treatment for people with dual diagnosis is well recognized. For the purpose of this paper, the World Health Organization definition of dual diagnosis was used; that is, a person diagnosed with an alcohol or drug use problem in addition to mental illness. This research explored the personal narratives of those who experience dual diagnosis using the Internet as a data source. An important consideration in using the Internet as a data source was that Web forums can offer a sense of anonymity, allowing people to share very detailed and personal information, and providing a rich source of qualitative data. The results produced five emergent themes: spiralling out of control – again!, getting help and giving support, treating both the addiction and mental illness, having meaning and being active, and being honest with self and others. The results indicate that individuals who experience dual diagnosis are often left to navigate their personal treatment requirements across two diverse systems, and were generally not satisfied with the conflictual advice received across these two systems (i.e. alcohol and other drug and mental health services). This study has produced valuable insights related to consumer‐perceived service barriers and enablers.
INTERNATIONAL WELFARE AND EMPLOYMENT LINKAGES ARISING FROM MINIMUM WAGES*
Authors: Egger Hartmut , Egger Peter , Markusen James R.
Published: July 2012

We formulate a two‐country model with monopolistic competition and heterogeneous firms to reconsider labor market linkages in open economies. Labor market imperfections arise by virtue of country‐specific real minimum wages. Abstracting from selection of just the best firms into export status, standard effects on marginal and average firm productivity are reversed in our model, yet there are significant gains from trade arising from employment expansion. In addition, we show that with firm heterogeneity an increase in one country’s minimum wage triggers firm exit in both countries and thus harms workers at home and abroad.
TOUGH LOVE AND INTERGENERATIONAL ALTRUISM*
Authors: Bhatt Vipul , Ogaki Masao
Published: July 2012

This article develops and studies a tough love model of intergenerational altruism. We model tough love by modifying the Barro‐Becker standard altruism model in two ways. First, the child’s discount factor is endogenously determined, so lower childhood consumption leads to a higher discount factor later in life. Second, the parent evaluates the child’s lifetime utility with a constant high discount factor. Our model predicts that parental transfers will fall when the child’s discount factor falls. This is in contrast with the standard altruism model, which predicts that parental transfers are independent of exogenous changes in the child’s discount factor.
Frequent bird movements across a highly fragmented landscape: the role of species traits and forest matrix
Authors: Neuschulz E. L. , Brown M. , Farwig N.
Published: July 2012

Previous studies that tracked the movements of single bird species within human‐modified landscapes have shown that the ability of forest birds to move across matrix habitat differs among species. Functional guild specificity as well as landscape characteristics have been shown to influence bird movements, entailing different movement behaviour of birds within a community. Studies investigating how both these factors influence the movements of entire bird assemblages across fragmented landscapes are essential but have rarely been conducted. In this study, we determined how species’ traits and different forest matrices influence bird movements among nine forest patches in a highly fragmented South African landscape. We combined 90 h of bird observations with capture–mark–recaptures (104 754 mist‐net hours) to distinguish between movements among patches (all birds that conduct long‐distance movements across the landscape) and movements within patches (all resident birds that conduct only short‐distance movements within a fragment). Overall, we detected a high bird movement activity across the fragmented landscape. Dietary specialization, habitat affinity and body mass strongly shaped the relative distribution of bird species across the nine fragments with frugivorous birds, forest specialists and large‐bodied species showing the highest movement abilities. In contrast, resident insectivores and forest generalists tended to move only within particular forest fragments. Our results suggest that remnant forest fragments may represent valuable stepping stones as well as permanent habitat for local bird assemblages. We emphasize that beside the conservation of natural forests, the maintenance of nearby, structurally rich forest fragments is pivotal in maintaining regional forest bird assemblages in human‐modified landscapes.
GEOCHEMICAL ANALYSIS OF THE SEDIMENTS IN AND AROUND AN EARLY NEOLITHIC WELL NEAR BRODAU, GERMANY*
Authors: TINAPP C. , SCHNEIDER B. , STÄUBLE H.
Published: July 2012

The discovery of wells of the linear pottery culture since 1990 has led to new insights on the ability and needs of humans at this time. The still small number of about 20 wells in Europe, compared to the much greater number of known settlements of this period, led to the assumption that they were built for special purposes, other than the water supply for the whole village. Investigations on the origin of archaeosediments of a more than 7000‐year‐old and 4.2 m deep well from the linear pottery culture in north‐west Saxony, Germany were carried out by geochemical analysis to improve our knowledge of the building, the usage and the decay of this wooden construction. Special emphasis was put on the material around two 10‐week‐old piglets that were intentionally deposited in the construction pit. Three major units—the sediment in the well, the infilling of the construction pit and the surrounding gravels—influenced by lateral transport of fine clay could be identified and described.
Evolution of Nesting Height in an Endangered Hawaiian Forest Bird in Response to a Non‐Native Predator
Authors: VANDERWERF ERIC A.
Published: July 2012

Abstract:  The majority of bird extinctions since 1800 have occurred on islands, and non‐native predators have been the greatest threat to the persistence of island birds. Island endemic species often lack life‐history traits and behaviors that reduce the probability of predation and they can become evolutionarily trapped if they are unable to adapt, but few studies have examined the ability of island species to respond to novel predators. The greatest threat to the persistence of the Oahu Elepaio (Chasiempis ibidis), an endangered Hawaiian forest bird, is nest predation by non‐native black rats (Rattus rattus). I examined whether Oahu Elepaio nest placement has changed at the individual and population levels in response to rat predation by measuring nest height and determining whether each nest produced offspring from 1996 to 2011. Average height of Oahu Elepaio nests increased 50% over this 16‐year period, from 7.9 m (SE 1.7) to 12.0 m (SE 1.1). There was no net change in height of sequential nests made by individual birds, which means individual elepaios have not learned to place nests higher. Nests ≤3 m off the ground produced offspring less often, and the proportion of such nests declined over time, which suggests that nest‐building behavior has evolved through natural selection by predation. Nest success increased over time, which may increase the probability of long‐term persistence of the species. Rat control may facilitate the evolution of nesting height by slowing the rate of population decline and providing time for this adaptive response to spread through the population.
The Significance of Heart Rate Turbulence in Predicting Major Cardiovascular Events in Patients after Myocardial Infarction Treated Invasively
Authors: Cebula Sylwia , Sredniawa Beata , Kowalczyk Jacek , Musialik‐Lydka Agata , Wozniak Aleksandra , Sedkowska Agnieszka , Swiatkowski Andrzej , Kalarus Zbigniew
Published: July 2012

Introduction: The role of heart rate turbulence (HRT) related to baroreflex sensitivity in predicting mortality after myocardial infarction (MI) has been confirmed by several investigators. However, the significance of HRT in predicting major adverse cardiovascular events (MACE) following acute MI is unknown.

Purpose: To analyze the prognostic value of HRT and other independent risk factors associated with autonomic regulation of MACE.

Methods: HRT was assessed based on 24‐hour Holter recordings in 500 patients (pts) with acute MI treated invasively (352 M, aged 60.58 years). Turbulence onset (TO,%), slope (TS, ms/RR interval) and timing (TT) were calculated. TO ≥ 0, TS ≤ 2.5 and TT ≥ 10 were considered abnormal; classic and own categories were defined. Time domain heart rate variability (HRV) parameters were also calculated. Within 30.1 ± 15.1 months of follow‐up, MACE occurred in 116 pts.

Results: Abnormal TO, TS, and TT were significantly more frequent in patients with MACE (P < 0.05 for each parameter, classic and own categories). In long‐term follow‐up, the largest differences in MACE were observed in patients with own category comprising abnormal TO, TS, and TT. Combining HRT parameters with SDNN (total HRV index) augmented their predictive value. Independent risk factors for MACE were TT, SDNN and rMSSD (a parasympathetic activity index) (HR 2.44, 1.71 and 1.69 respectively; P < 0.05).

Conclusion: Abnormal HRT distinguishes patients at risk of MACE after MI. Own category encompassing three abnormal HRT parameters best differentiates patients at risk of MACE. Turbulence timing is a strong independent risk factor for MACE following MI.
The Presence of Giant Epsilon Waves in a Patient with Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: Bao Huihui , Hong Kui , Li Juxiang , Cheng Xiaoshu
Published: July 2012

Epsilon wave, which is a major diagnosis criterion for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVD/C), is defined as small amplitude potentials. The present case is a 49‐year‐old man with a history of syncope and palpitations for 6 months. The ECG documented ventricular tachycardia (VT) when the patient has palpitations. However, there has been a giant epsilon wave in sinus rhythm. Electroanatomic mapping also has a prominent double potential identified on ABL catheter. The amplitude of epsilon wave reached 0.9 mV, which might be the maximum epsilon wave until now.
Usefulness of Ki‐67 (MIB‐1) immunostaining in the diagnosis of pulmonary sclerosing hemangiomas
Authors: Kim Baek‐hui , Bae Yoon‐sung , Kim Se Hoon , Jeong Hyeong‐jae , Hong Soon Won , Yoon Sun Och
Published: July 2012

Pulmonary sclerosing hemangioma (PSH) is an uncommon lung neoplasm with a clinical outcome that is generally benign. However, differentiating PSH from pulmonary carcinoma is sometimes difficult as both lesions share similar histopathologic and immunohistochemical features. In this study, we investigated the usefulness of Ki‐67 (MIB‐1) immunostaining in the diagnosis of PSH. We compared the staining pattern for Ki‐67 (MIB‐1) in 29 cases of typical PSH and 79 cases of pulmonary non‐small cell carcinoma (NSCLC) using an immunohistochemical method on formalin‐fixed paraffin‐embedded tissues. In all studied PSH cases, we noted cell membrane and cytoplasmic staining for Ki‐67 (MIB‐1), but this was not observed in any of the NSCLC cases. The Ki‐67 proliferation index was lower in PSH than in the NSCLC cases (mean, 1.1% vs mean, 5.5%; p < 0.001). These findings suggest that cell membrane and cytoplasmic staining for Ki‐67 (MIB‐1), as well as the Ki‐67 proliferation index, may be useful for distinguishing PSH from pulmonary carcinoma.
A Third Method of Ethics?
Authors: Crisp Roger
Published: July 2012

In recent decades, the idea has become common that so‐called virtue ethics constitutes a third option in ethics in addition to consequentialism and deontology. This paper argues that, if we understand ethical theories as accounts of right and wrong action, this is not so. Virtue ethics turns out to be a form of deontology (that is, non‐consequentialism). The paper then moves to consider the Aristotelian distinction between right or virtuous action on the one hand, and acting rightly or virtuously on the other. It is claimed that virtue might play an important role in an explanation of acting virtuously (as it does in Aristotle’s ethics), but that such explanations can be charged with ‘double‐counting’ the moral value of the virtues. The paper concludes that, if we focus on the question of the value of virtue, rather than on the notion of right action, there is room for a self‐standing and important view which could be described as virtue ethics.
Boghossian’s Inference Argument against Content Externalism Reversed*
Authors: PÉREZ OTERO MANUEL
Published: July 2012

I deal here with one of Boghossian’s arguments against content externalism, related to ourinferential rationality(to use his term). According to his reasoning, the apriority of our logical abilities is inconsistent with certain externalist assumptions. Nevertheless, the problem constitutes an important challenge foranytheory of content, not just for externalism. Furthermore, when we examine what internalists may propose to solve the problem, we see that externalists have at their disposal a more promising repertoire of possible replies than internalists. In that sense, insofar as Boghossian’s scenario is relevant to the debate externalism/internalism, it can be seen (against Boghossian’s original intention) as providing additional evidence for content externalism.
Case study evaluation of the Rayleigh integral method
Authors: Herrin D. W. , Wu T. W. , Seybert A. F.
Published: July 2012

The Rayleigh integral is based on the assumption that the vibrating surface is flat and part of an infinite rigid baffle. Though approximate, the Rayleigh integral can evaluate the sound power radiated by a vibrating surface in a fraction of the time required by the boundary element method. Three case studies were conducted to evaluate the reliability of the Rayleigh integral. Specifically, the Rayleigh integral was used to predict the sound power from a wheel-rail structure, a gearbox, and an engine. In each case, Rayleigh integral results were compared with boundary element results. The results indicated that sound power compared well with that obtained using the boundary element method. The differences were less than 5 dB except at low frequencies. However, the Rayleigh integral did not accurately predict the sound pressures at field points. The results suggested that the Rayleigh integral could be used in place of the more time intensive boundary element method for sound power calculations.
Forcing function models for structures excited by low-speed flow
Authors: Hwang Y. F. , Hambric S. A.
Published: July 2012

Predictions of flow-induced flat plate vibrations using a finite-element structural model and the modified Corcos cross-spectral model as the forcing function [Hambric and Hwang, Proceedings of Inter-Noise 2000, Nice, France, 27–30 August (2000)] agree very well with the measured [Han et al., J. Sound Vib. 227(4), 685–709 (1999)] plate vibrations. However, extremely fine finite-element meshes had to be used to resolve the streamwise variations of the coherence function. This approach is not computationally tractable for most large complex structures. This paper discusses a practical approach of utilizing an approximated discrete forcing function model, which represents only the low-wavenumber region of the excitation in terms of the cross-spectra of grid forces. The high-wavenumber (convective ridge) content of the excitation is thus ignored. This method is believed more feasible in practice because the finite-element meshes now need only resolve the structural wave scale instead of the convective turbulence scale. This approximated forcing function model is assessed against the exact model and found to be satisfactory in most cases except when the structural mode wavenumbers are close to the convective ridge. [Work supported by ONR, Code 333.]
A computational approach for flow-acoustic coupling in deep cavities
Authors: Radavich Paul M. , Selamet Ahmet , Novak James M.
Published: July 2012

The quarter wave resonator, which produces a narrow band of high acoustic attenuation at regularly spaced frequency intervals, is a common type of silencer used in ducting systems. The presence of mean flow, however, is likely to promote an interaction between these acoustic resonances and the flow. The coupling for some discrete flow conditions leads to the production of both large wave amplitudes in the side branch and high noise levels in the main duct. Thus, the quarter wave resonator may become a noise source rather than a silencer. The present approach uses computational fluid dynamics to determine both the mean flow and acoustic fields simultaneously by solving the unsteady, turbulent, and compressible Navier–Stokes equations. By coupling the interaction between the mean flow fluctuations and vortices with the acoustic field, this method is capable of determining when flow-acoustic coupling occurs and how variations in the geometry and flow conditions influence the acoustic pressure amplitudes.
Hybrid active/passive control of sound radiation from panels with constrained layer damping and model predictive feedback control
Authors: Cabell Randolph
Published: July 2012

Feedback control of aircraft sidewall panels has been studied for reducing interior noise due to turbulent boundary layer excitation of the fuselage. Online adaptation of the feedback controller parameters can be used to track pressure, temperature, and structural variations, but the associated computational burden can be overwhelming. This work describes a hybrid active/passive control approach where the passive components reduce the complexity of the active system. Constrained layer damping provides damping at high frequencies, and a generalized predictive controller is used at low frequencies. Experiments were conducted on a panel subjected to broadband speaker excitation in a transmission loss facility. A piezoelectric actuator provided control input to the panel, accelerometers provided error feedback. Two sensing configurations were studied: one used full-state feedback to control radiated sound power, estimated from 15 accelerometers on the panel; the other used dynamic output feedback to control the summed responses of 4 accelerometers. Active noise reduction for different locations of constrained layer damping are discussed. The addition of the constrained layer damping makes it possible to achieve good noise reduction with the simpler 4-accelerometer sensing configuration.
Modeling the normal modes and acoustics of a jet engine
Authors: Ireland Laralee G. , Sommerfeldt Scott D.
Published: July 2012

Fan noise is a major contributor to the noise problem of an airplane jet engine. An understanding of the acoustics of the jet engine is necessary in order to successfully control the fan noise of the engine. A numerical boundary element method model has been developed using Sysnoise to simulate active noise control of fan noise in the engine duct. Control of multiple radial modes is targeted through the use of a modal controller using Newton’s algorithm. Results from the model are compared with measurements made previously using the NASA Glenn Research Center test rig facility. Currently work is progressing on the numerical implementation of control on a more realistic geometry.
Evaluation of efficient passive damping treatments for aircraft cabin noise control
Authors: Mathur Gopal P. , Lee Joshua T. , Simpson Myles A.
Published: July 2012

Visco-elastic damping has been used as one type of passive noise control treatment to reduce noise transmission through fuselage skin pan- els. In most conventional applications, uniform coverage of the damping layer is applied to skin panels. Recently, stand-off damping has also been used for aircraft noise reduction. Effects of various damping treatments have been well documented in the published literature. In this paper, some weight-efficient damping treatments, such as edge and wedge damping, are considered. The main objective of this research work is to evaluate passive noise control treatments for a stiffened sidewall section using analytical models. The goal is to achieve an improvement of 3–5 dB in the transmission loss of the sidewall over a conventional passive treatment, over the frequency range from 400 to 2000 Hz. The effect of various damping treatments on the vibration response of a stiffened panel to a point force input, acoustic pressure field and turbulent boundary layer excitation were investigated using a NASTRAN spectral model. The finite-element model of the stiffened panel included visco-elastic damping with and without constraining layer. The material properties of a commercially available constrained layer foam damping were used.
The community impact of rogue transportation sources
Authors: Zimmer Ithan , Wilson Charles , Dresnack Robert
Published: July 2012

This study investigates the contributions of atypical transportation noise sources to community noise and relates these contributions to policymaking and resource allocation. Small percentages of aircraft and surface transportation vehicles make a significant contribution to noise levels as measured by day-night sound level and other descriptors. Rogue sources are loosely defined in this study as anomalous sources that have a large impact on community noise. Included are sources that do not comply with regulatory standards due to intentional modifications or due to failure of noise suppression components. Also included are sources that produce noise levels well above reasonably attainable levels despite attainment of regulatory standards. Rogue source identification and assessment can be a component in policymaking and resource allocation. Cost savings can be realized by reducing noise at the source vice by the path. For instance, surface transportation noise standards based on best-available technology and vigorous enforcement can be more cost-effective than erection of noise barriers. In this case, the cost is borne by the offender rather than by the community at-large. The authors analyze and quantify the noise contribution of rogue sources and suggest appropriate noise mitigation.
Global players in acoustic standardization
Authors: Brinkmann Klaus
Published: July 2012

The World Trade Organization has identified international standardization as a key to realization of worldwide free trade. This identification underlined the importance of the work by nongovernmental international standardization bodies such as IEC and ISO as well as by governmental bodies such as the International Organization of Legal Metrology (OIML). In acoustics, each of these organizations deals with technical harmonization in a certain field: The work of both IEC/TC 29 ‘‘Electroacoustics’’ and OIML/TC 13 ‘‘Measuring instruments for acoustics and vibration’’ focuses on specification of performance characteristics and testing procedures for electroacoustical devices. Standardization of measuring methods for industrial products either emitting or reducing noise is the primary activity of ISO/TC 43 ‘‘Acoustics.’’ This lecture presents an introduction to how international standards in acoustics are developed along with a survey of the scopes and work programs of these three closely cooperating committees. Guidance on the estimation of the uncertainty inherent in standardized acoustical tests and measurements is a major technical issue. The role of national and regional standardization in acoustics will be noted. The European standards bodies, CEN and CENELEC, have clearly defined tasks within the European Economic Area related to acoustics.
Broadband acoustic backscattering from alewife fish: Experiment and analysis
Authors: Reeder D. Benjamin , Stanton Timothy K. , Chu Dezhang , Jech J. Michael
Published: July 2012

A series of laboratory scattering measurements and associated analysis have been conducted involving alewife fish (Alosa pseudoharengus). A greater-than-octave bandwidth, shaped, linearly swept, frequency modulated signal was used to insonify live, adult alewife that were tethered while being rotated. The acoustic scattering time series were measured in 1-deg increments of orientation angle over all angles in two planes of rotation. Dominant acoustic scattering mechanisms are identified through both spectral and time-domain (pulse compression) analyses. Results demonstrate the dependence of scattering strength upon frequency and angle of orientation in the lateral (horizontal) and dorsal/ventral aspects. The pulse compression processing of the echoes from the animals temporally resolves multiple returns from an individual which are correlated with size and orientation. [Work supported by ONR, NOAA and CICOR (Cooperative Institute for Climate and Ocean Research).]
In situ target strength measurements of a deep-water fish, orange roughy
Authors: Kloser Rudy J.
Published: July 2012

In situ target strength methods have been reported to be the best way to convert echo integration acoustic surveys into biomass. Detailed in situ target strength measurements were obtained by both drifting over and towing through aggregations of orange roughy at 700–800-m depths. The aggregations displayed a marked avoidance response at times to the deep-towed body and it was difficult to ascertain when single orange roughy targets were being detected. Using three frequencies, it was possible to include/exclude various targets in the selection process and have more confidence that the observed targets were the species of interest. Calibration of the data was simplified by suspending a sphere under the transducer for all the drift experiments. The extracted target strength histograms for the drift experiments were very broad with many modes, and distribution mean target strengths were sensitive to the density of the schools and also not surprisingly the concentration of other species. Towing experiments were highlighted by a marked avoidance response as the towed body neared the orange roughy schools. The extracted in situ target strength histograms showed that the mean target strength for diving orange roughy can decrease by 3.1 dB (50%).
Noise control engineering for the airport railway in Hong Kong—Setting the standards
Authors: Frommer Glenn
Published: July 2012

The Lantau and Airport Railway (LAR) is a 34-km electrical railway that connects Hong Kong Island to the new International Airport. Noise control engineering was implemented throughout the design of the project to provide a safe, comfortable, and maintainable environment both for the passengers and railway neighbors in the most cost-effective manner as possible, and minimize land take and land sterilization nearby the railway. To do so required a unique balance of noise and vibration specification and performance in the following areas: (i) a wheel/rail interface design integrating synergistically, the track and rolling stock design, (ii) the use of a noise assurance plan to manage the noise design of the rolling stock, (iii) the use of aggressive specifications for noise emissions, reverberation times, and building services within stations, (iv) the use of RASTI prediction to ensure proper design and delivery of the public address system, (v) the use of floating track slabs and other trackforms to minimize the transfer of structure-borne noise from the railway platforms to the overlying developments, and (vi) specialist training in acoustics and vibrations. This paper will summarize the key results of the LAR project.
Air handler sound power prediction method based on ARI Standard 260
Authors: Lind Stephen J.
Published: July 2012

A method of predicting air handler sound power based on ratings for a product line is described. The method provides octave band sound power levels based on ratings obtained using Air-Conditioning and Refrigeration Institute (ARI) Standard 260 Sound Rating Of Ducted Air Moving And Conditioning Equipment. Detailed sound power information for HVAC equipment is not always available, but it is important in accurately predicting noise levels in acoustically sensitive spaces. To address this need, a rating program was undertaken using ARI 260. This standard is a reverberant room technique for sound rating ducted air conditioning equipment using a reference sound source substitution method. Since sound travels from the source to receiver along numerous paths, this standard differentiates between sound power emanating from several common paths called components. Components for this project included ducted discharge, free inlet plus casing, ducted inlet and casing. The standard provides guidance on adequate number of fan sizes, appurtenances and operating characteristics. The intent of the project was to provide a model to predict sound power by unit size, component, operating condition and unit configuration. Good agreement was found between predicted levels and measured data.
Properties and applications of novel acoustical foams
Authors: Subramonian Suresh , Drzyzga Mae , Gilg Sandrine , Remy Laurent , Park Chung
Published: July 2012

This paper describes the unique properties of a new line of novel acoustical materials that has been developed for sound and vibration management. The materials are macrocellular thermoplastic foams made from polyolefin resin blends. Fire retardant grades have been developed to meet a variety of building and construction fire codes. The foams have several advantages over incumbent materials, including structural integrity, moisture resistance, ease of fabrication/installation and recyclability. This paper also reviews a case study involving the use of the new foams to significantly dampen the sound level of a noisy industrial facility. The sound pressure levels and reverberation decay times were measured in the target area with an integrating, real time 1/3-oct spectrum analyzer. Architectural acoustical analysis was performed using ray diagrams and Sabine calculations for determining the amount and optimal placement of the absorptive media to reduce the reverberant noise fields and sound reinforcing reflections. The thickness of the acoustic media was determined by matching the peak absorption frequencies of the foam to the peak noise frequencies of the source. After installation of the absorptive media as per specifications, the reduction in noise level was measured to validate the acoustical design.
Active control of sounds with large dynamic range
Authors: Brammer Anthony J. , Pan George J.
Published: July 2012

The performance of an active noise control system employing digital signal processing is influenced by the analog signal amplitudes within the input and output analog-digital (A/D) and D/A converters, and hence is sensitive to the sound pressure being controlled. While compensation is commonly provided within the algorithm for variations in input power (e.g., by normalizing the adaptation step size), the full dynamic range of the A/D and D/A subsystems is usually not realized. An analog gain control system has been developed consisting of linked, reciprocal variable gain amplifiers, so arranged that the changes in signal amplitude at the A/Ds and D/As are smaller than the changes in sound pressure of the acoustic system being controlled. The gain control system operates on the error and secondary source signals so as to maintain the error path impulse response unchanged. In this way the gain changes are transparent to the digital controller. The application of the method to an adaptive feed-forward active noise control system for a circumaural hearing protector, or headset, will be described. [Work supported by the Defence and Civil Institute of Environmental Medicine.]
Function word reduction: The role of adjacent stress
Authors: Lavoie Lisa M.
Published: July 2012

Monosyllabic function words in speech are often reduced from their full citation forms. Researchers have shown that reduction is influenced by part of speech, predictability, prosody, and disfluency. This work isolates the role of an additional factor, preceding stress, in function word reduction by analyzing the realization of ‘‘for’’ in a highly controlled corpus. Five American English speakers read pairs of disyllabic words with initial or final stress (BOOty, bouTIQUE) in the frame ‘‘Please say [word] for me.’’ Two speakers show striking sensitivity to preceding stress, always producing strong–weak alternations, such that strong ‘‘for’’ follows a weak syllable and vice versa. The rimes in the strong versions average 90 ms while the weak are just 50 ms. The strong rimes consist of a clearly segmentable vowel plus /r/. In the weak, however, /r/ is not distinguishable in the acoustics as its own segment; rather, it influences the vowel F3 value. The other three speakers always realize ‘‘for’’ as weak, with an average duration of 39 ms after either stressed or unstressed syllables. Though limited, these results suggest that some speakers construct rhythmic groupings in speech production. Further work will determine whether similar effects are found in spontaneous speech.
The effects of stress and final position on sounds of Jicarilla Apache
Authors: Tuttle Siri
Published: July 2012

The study of word-level prosody in Athabaskan languages is complicated by morphology and intonation. Stems are both frequently stressed and frequently word-final or phrase-final. This means that final lengthening confounds acoustic measurements of stress. This study of Jicarilla (Eastern) Apache attempts to sort out the acoustic effects of phrase-finality from those of stress. Syllables taken from a recorded text were measured for duration of onsets, codas and peaks. Phrasal position was noted as initial/noninitial and final/nonfinal. When only nonfinal syllables are examined, stress is marked significantly by increased vowel length (p=0.02), controlling for phonemic vowel length. This distinction remains when stressed and unstressed final syllables are compared, but is weaker (p=0.04). When only stressed syllables are examined, vowels are significantly longer when the syllable is final (p=0.0001). However, length of codas is also significantly greater in final stressed syllables (p=0.027), and this effect is not associated with stress. Thus despite the large effect of final lengthening, Jicarilla Apache still distinguishes stressed from unstressed syllables using duration within syllables. It is the ratio of rhyme elements to one another which contains the cue.
Sentence intonation and syllable stress in speech produced during simultaneous communication
Authors: Whitehead Robert , Whitehead Brenda , Schiavetti Nicholas , Metz Dale Evan , Gallant Deborah
Published: July 2012

This study investigated prosodic variables of syllable stress and intonation contours in speech produced during simultaneous communication. Simultaneous communication (SC) refers to speech combined with manually coded English (sign and finger spelling) for the production of each word of an utterance and is used in communication between hearing and deaf persons. Ten normal hearing, experienced sign language users were recorded under SC and speech-only (SO) conditions speaking a set of sentences containing stressed versus unstressed versions of the same syllables and a set of sentences containing interrogative versus declarative versions of the same words. Results indicated longer sentence durations for SC than SO for all speech materials. Vowel duration and fundamental frequency differences between stressed and unstressed syllables as well as intonation contour differences between declarative and interrogative sentences were essentially the same in both SC and SO conditions. The conclusion that prosodic rules were not violated in SC is consistent with previous research indicating that temporal alterations produced by simultaneous communication do not involve violations of other temporal rules of spoken English.
Relationships among temporal patterns of speech production in English
Authors: Smith Bruce L.
Published: July 2012

Although various temporal patterns have been noted in English, possible relationships among these different characteristics generally have not been examined. In part, this may be because it is assumed that speakers show temporal patterns such as phrase-final vowel lengthening, vowel lengthening preceding voiced obstruents, etc., to essentially the same degree. However, recent findings suggest that there can be considerable variation among speakers in the extent to which they manifest such temporal properties. Thus, the present study investigated the possibility that subjects who exhibit a particular temporal property in their speech to a greater/lesser degree than other speakers might also tend to show other patterns to a greater (or lesser) extent. The same temporal characteristics were also examined to determine whether they varied as a result of speakers different syllable durations. A number of relationships among the various parameters were observed. For example, speakers with shorter syllable durations tended to show greater phrase-final vowel lengthening than speakers with longer syllable durations. In contrast, subjects with shorter syllable durations showed less vowel lengthening preceding voiced versus voiceless consonants than speakers with longer syllable durations. Possible reasons for these temporal variations and interrelationships will be considered.
Seasonal variations of density and sound-speed contrasts of the krill Euphausia pacifica
Authors: Mukai Tohru , Iida Kohji , Mikami Hisayuki , Matsukura Ryuichi
Published: July 2012

In recent years, acoustic technology has been used extensively to estimate krill abundance. Acoustic assessment is required to gain a precise estimate of krill target strength. However, predictions of target strength from theoretical scattering models are often influenced by the swimming angles and density of the krill, and sound-speed contrasts between krill and seawater. Density and sound-speed contrasts are known to show annual cycles. In this study, seasonal variations of the specific density and sound-speed contrasts of Euphausia pacifica are presented. Biological sampling was carried out during twilight, when the sound-scattering layer migrates up to the surface. The specific densities of E. pacifica were measured, using a series of variable density glycerol solutions, within 48 h of net sampling. Sound-speed measurements were performed 2 hours after net sampling, using a T-shaped velocimeter with two transducers mounted on the ends of a horizontal tube. In 1999, the seasonal changes in specific densities and sound speed contrasts were ca. 1% and 3%, respectively. When calculated using Stanton’s straight cylinder model, these seasonal changes yielded a difference of approximately 5 dB in the target strength of E. pacifica.
Dynamic insertion loss measurements of sound attenuators at low frequencies
Authors: Lilly Jerry G. , Partain James D.
Published: July 2012

For decades the duct silencer industry has relied on ASTM E 477 as a standard for measuring the acoustic and aerodynamic properties of passive duct silencers. Historically, there has been significant concern regarding the accuracy and reliability of the measured dynamic insertion loss values for duct silencers at 125 Hz and below. The uncertainty at low frequencies has been blamed on several factors including: (1) inaccurate determination of sound level in reverberation chambers due to inaccurate spatial averaging (e.g., low modal density), and (2) varying acoustic output power from the electronic signal source due to a different impedance seen by the loudspeaker (with and without the test specimen in the duct). This paper presents a third reason for the low-frequency variability, which is likely to be more significant than all others combined. It will show that the problem is caused by acoustic resonances in the empty test duct, and these resonances will occur in every facility that is constructed in accordance with the test standard. The authors will present test data collected in a NVLAP accredited laboratory verifying this low-frequency effect, and also recommend specific changes to ASTM E477 which could eliminate this problem.
Anechoic wedge design and development/anechoic chamber qualification testing
Authors: Eckel Alan , Ver Istvan
Published: July 2012

The initial research conducted at Harvard University’s Electro Acoustic Laboratory for the development of the anechoic chamber will be reviewed in this presentation. These findings, which were originally presented in the Office of Scientific Research and Development National Defense Research Committee Report No. 4190 (OSRD, No. 4190), will be discussed. The research conducted by Leo L. Beranek and his colleagues during WWII established the basic design and construction for anechoic wedges and chambers for years to come. Contemporary design and materials used in anechoic wedge construction have evolved to encompass a variety of room acoustic treatments, to include fiberglass, foam, and metallic wedges. Design and construction of current commercially available chambers and wedges will be reviewed. The second half of the presentation will focus on the development of anechoic and hemianechoic chamber qualification procedures to current ISO and ANSI standards. The use of various sound sources will be discussed as well as the correlation between these standards and other test methods in determining chamber performance.
Method for evaluating the attenuation of acoustical covers used in high-end computer systems
Authors: Shaw Jennifer A. , Nobile Matthew A. , Donald Brian
Published: July 2012

High-end computer systems, such as those used in the Information Technology and Telecommunications (ITT) industry, have become increasingly noisy in recent years, due to the amount of airflow needed to keep them functioning properly. As sound power levels increase, the systems run the risk of exceeding their noise-limit specifications. One solution is to incorporate acoustical covers as a noise control measure. By attenuating the amount of noise emitted from the machine, the overall measured sound power level will decrease, thereby allowing the system to pass specifications. However, a method for evaluating the amount of attenuation these acoustical covers provide is needed. To date, the attenuation has been measured by using actual system frames that are under development, which are often hard to acquire and introduce too many variables into the measurement. Also, both front and rear covers are needed for the measurements, so that the attenuation of just one cover is not easily obtained. This paper proposes the use of a test box as an evaluation tool for measuring the attenuation of a single cover. The test box provides a uniform and repeatable method that yields a more useful metric for rating cover performance.
Investigation of noise reflections using test signals
Authors: Herman Lloyd , Giesey Jeff , Ghent Jeremy
Published: July 2012

Repeatable test signals for use with a loudspeaker system were generated to investigate noise reflections from traffic noise barrier walls. Four classes of signals were considered: impulses, maximum-length sequences, pseudorandom binary sequences, and linear frequency-modulated sine waves or chirps. Overall, the chirps yielded the most information from initial experiments. The test system was applied to single and parallel barrier configurations to identify the number of significant reflections, to determine the level of the reflections relative to the direct signal and to quantify the contribution of the reflections to the overall sound level at receivers of interest. For receivers located on the community side of parallel barrier configurations the contribution of the reflections was found to increase with receiver distance from the barrier.