bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrent glomerular disease after kidney transplantation: An update of selected areas and the impact of protocol biopsy
Authors: Morozumi Kunio , Takeda Asami , Otsuka Yasuhiro , Horike Keiji , Gotoh Norihiko , Watarai Yoshihiko
Published: May 2014

Recurrence of native kidney disease following kidney transplantation affects between 10% and 20% of patients, and accounts for up to 8% of graft failures. In a considerable number of recipients with transplant glomerulopathy, it is impossible to distinguish between recurrent and de novo types. An accurate estimate of the incidence of recurrence is difficult due to limitations in the diagnosis of recurrent glomerulonephritis. De novo glomerular lesions may be misclassified if histological confirmation of the patient's native kidney disease is lacking. Asymptomatic histological recurrence in renal allografts may be missed if protocol biopsies are not available. Studies based on protocol biopsy are pivotal to accurately estimate the incidence of recurrence. Many factors are known to influence recurrence of kidney disease after transplantation, including the type and severity of the original disease, age at onset, interval from onset to end‐stage renal disease, and clinical course of the previous transplantation. Early recognition of recurrence is possible in several glomerular diseases. Factors such as the existence of circulating permeability factors, circulating urokinase receptor and anti‐phospholipase A2 receptor antibody, as well as disorders of complement regulatory proteins like factor I mutation and factor H mutation factors are expected to be useful predictors of recurrence. Peculiar clinical course of atypical haemolytic uremic syndrome after kidney transplantation is an informative sign of recurrent glomerular disease. These factors play pivotal roles in the development of recurrence of certain types of glomerulopathies. Understanding the pathogenesis of recurrent glomerulonephritis is critical to optimize prevention as well as treat individual cases of recurrent glomerulonephritis. Subclinical recurrence of IgA nephropathy after kidney transplantation is well recognized. Only protocol biopsies of clinically silent recipient can provide the accurate prevalence of recurrent IgA nephropathy. The study of recurrent glomerulonephritis will contribute not only to improving long‐term graft survival, but also to clarifying the pathogenesis of glomerulonephritis. Protocol biopsy is one the most effective methods for elucidating the pathogenesis of recurrent glomerulonephritis.
Root traits predict decomposition across a landscape‐scale grazing experiment
Authors: Smith Stuart W. , Woodin Sarah J. , Pakeman Robin J. , Johnson David , van der Wal René
Published: May 2014

Root litter is the dominant soil carbon and nutrient input in many ecosystems, yet few studies have considered how root decomposition is regulated at the landscape scale and how this is mediated by land‐use management practices. Large herbivores can potentially influence below‐ground decomposition through changes in soil microclimate (temperature and moisture) and changes in plant species composition (root traits).

To investigate such herbivore‐induced changes, we quantified annual root decomposition of upland grassland species in situ across a landscape‐scale livestock grazing experiment, in a common‐garden experiment and in laboratory microcosms evaluating the influence of key root traits on decomposition.

Livestock grazing increased soil temperatures, but this did not affect root decomposition. Grazing had no effect on soil moisture, but wetter soils retarded root decomposition. Species‐specific decomposition rates were similar across all grazing treatments, and species differences were maintained in the common‐garden experiment, suggesting an overriding importance of litter type. Supporting this, in microcosms, roots with lower specific root area (m2 g−1) or those with higher phosphorus concentrations decomposed faster.

Our results suggest that large herbivores alter below‐ground carbon and nitrogen dynamics more through their effects on plant species composition and associated root traits than through effects on the soil microclimate.
Creating and capturing value from external knowledge: the moderating role of knowledge intensity
Authors: Denicolai Stefano , Ramirez Matias , Tidd Joe
Published: May 2014

Business model innovation (BMI) often involves the acquisition of external resources, their integration with and adaptation to internal capabilities and the exploitation of these novel combinations to create and capture value in new ways. However, studies focusing on the relationships among capabilities, BMI and firm performance are rare. In this paper, we adopt broader measures of internal and external knowledge, which include codified intangibles such as patents and copyrights, and examine the effects the combinations and interactions have on sales growth based on a dataset of 310 firms from four European countries. Using the broader measure of knowledge, we find support for the curvilinear relationship reported in studies using research and development‐intensity as a proxy. However, we also find that firms with low levels of internal knowledge benefit most from an ‘optimal’ investment in externally generated knowledge, but the influence on sales growth is very sensitive to the degree of external knowledge acquired. By contrast, knowledge‐intensive firms are relatively freer in defining their knowledge sourcing strategy. We discuss the implications for exploiting knowledge and complementary assets in BMI.
Piscivore Responses to Enhancement of the Channelized Kissimmee River, Florida, U.S.A.
Authors: Jordan Frank , Arrington D. Albrey
Published: May 2014

Evaluation of the success of ecosystem restoration projects requires identification of appropriate ecological metrics. Comparison of reconstructed food webs (or subsets thereof) from restored and non‐restored habitats may be a valuable tool to evaluate restoration success because food webs help identify critical predator–prey relationships, keystone species, relative importance of direct and indirect trophic interactions, and other aspects of ecological function. We compared the diets of apex predatory fishes collected from enhanced and non‐enhanced portions of the channelized Kissimmee River, Florida, USA to determine whether food web structure responded to experimental hydrologic manipulations. Diets were reconstructed for black crappie (Pomoxis nigromaculatus), bowfin (Amia calva), chain pickerel (Esox niger), Florida gar (Lepisosteus platyrhincus), largemouth bass (Micropterus salmoides), and warmouth (Lepomis gulosus) collected from enhanced and non‐enhanced portions of the Kissimmee River. Prey eaten by apex predatory fishes in the enhanced portion of the Kissimmee River were quantitatively and qualitatively different from prey eaten in non‐enhanced portions of the river. Predators in the enhanced portion of the river had fewer empty stomachs, more prey items per individual, more prey types per individual, more fish prey per individual, greater overall richness of prey, and a multivariate suite of prey distinct from predators in non‐enhanced portions of the river. Results from hydrologic manipulations suggest that large‐scale restoration of hydrologic linkages between the main channel and floodplain habitats will positively affect food web structure and ecosystem function in the Kissimmee River.
Comprehensive assessment of the long‐term safety of pirfenidone in patients with idiopathic pulmonary fibrosis
Authors: Valeyre Dominique , Albera Carlo , Bradford Williamson Z. , Costabel Ulrich , King Talmadge E. , Leff Jonathan A. , Noble Paul W. , Sahn Steven A. , du Bois Roland M.
Published: May 2014

Background and objective

Pirfenidone is an oral antifibrotic agent that is approved in several countries for the treatment of idiopathic pulmonary fibrosis (IPF). We performed a comprehensive analysis of safety across four clinical trials evaluating pirfenidone in patients with IPF.

Methods

All patients receiving pirfenidone 2403 mg/day in the Phase 3 CAPACITY studies (Studies 004 and 006) and all patients receiving at least one dose of pirfenidone in one of two ongoing open‐label studies in patients with IPF (Studies 002 and 012) were selected for inclusion. Safety outcomes were evaluated from baseline until 28 days after the last dose of study drug.

Results

A total of 789 patients were included in the analysis. The median duration of exposure to pirfenidone was 2.6 years (range, 1 week–7.7 years), and the cumulative total exposure was 2059 person exposure years (PEY). Gastrointestinal and skin‐related events were the most commonly reported adverse events; these were almost always mild to moderate in severity, and rarely led to treatment discontinuation. Elevations (>3× upper limit of normal) in alanine aminotransferase (ALT) or aspartate aminotransferase (AST) occurred in 21/789 (2.7%) patients; the adjusted incidence of AST/ALT elevations was 1.7 per 100 PEY.

Conclusions

This comprehensive analysis of safety in a large cohort of IPF patients receiving pirfenidone for a total of 2059 PEY demonstrates that long‐term treatment with pirfenidone is safe and generally well tolerated.
Impact of Buccotherm® on xerostomia: a single blind study
Authors: Alpöz Esin , Çankaya Hülya , Güneri Pelin , Epstein Joel B. , Boyacioglu Hayal , Kabasakal Yasemin , Ocakci Pınar Talu
Published: May 2014

Objective

The purpose of this single blind study was to investigate effects of Buccotherm® spray on subjective symptoms of xerostomia patients.

Methods

Twenty patients with dry mouth complaint were instructed to use placebo six times a day for 2 weeks. After a wash period, mineral water spray was provided. Patients were asked to reply questions regarding dry mouth using visual analog scale (VAS). Baseline and subsequent subjective findings on 1 hour after the application of the materials at the end of 1st, 7th, and 14th days were recorded.

Results

At the end of 14‐day treatment, no statistically significant differences were observed between the efficacy of placebo and commercial mineral water dental spray (p > 0.05). The VAS scores revealed that difficulty in mastication (p = 0.006), difficulty in swallowing (p = 0.00), need to sip liquids while eating (p = 0.000), difficulty in speech (p = 0.003), and waking up at night to sip water (p = 0.005) were statistically lower for placebo than commercial mineral water spray.

Conclusion

The commercial mineral water dental spray was not more efficient than placebo in the management of dry mouth‐related symptoms.

Clinical relevance

This study emphasizes the fundamental role of saliva in oral health and evaluates the clinical utility of a commercial dental spray.
Suppression of OsRAD51D results in defects in reproductive development in rice (Oryza sativa L.)
Authors: Byun Mi Young , Kim Woo Taek
Published: May 2014

The cellular roles of RAD51 paralogs in somatic and reproductive growth have been extensively described in a wide range of animal systems and, to a lesser extent, in Arabidopsis, a dicot model plant. Here, the OsRAD51D gene was identified and characterized in rice (Oryza sativa L.), a monocot model crop. In the rice genome, three alternative OsRAD51D mRNA splicing variants, OsRAD51D.1, OsRAD51D.2, and OsRAD51D.3, were predicted. Yeast two‐hybrid studies, however, showed that only OsRAD51D.1 interacted with OsRAD51B and OsRAD51C paralogs, suggesting that OsRAD51D.1 is a functional OsRAD51D protein in rice. Loss‐of‐function osrad51d mutant rice plants displayed normal vegetative growth. However, the mutant plants were defective in reproductive growth, resulting in sterile flowers. Homozygous osrad51d mutant flowers exhibited impaired development of lemma and palea and contained unusual numbers of stamens and stigmas. During early meiosis, osrad51d pollen mother cells (PMCs) failed to form normal homologous chromosome pairings. In subsequent meiotic progression, mutant PMCs represented fragmented chromosomes. The osrad51d pollen cells contained numerous abnormal micro‐nuclei that resulted in malfunctioning pollen. The abnormalities of heterozygous mutant and T2 Ubi:RNAi‐OsRAD51D RNAi‐knock‐down transgenic plants were intermediate between those of wild type and homozygous mutant plants. The osrad51d and Ubi:RNAi‐OsRAD51D plants contained longer telomeres compared with wild type plants, indicating that OsRAD51D is a negative factor for telomere lengthening. Overall, these results suggest that OsRAD51D plays a critical role in reproductive growth in rice. This essential function of OsRAD51D is distinct from Arabidopsis, in which AtRAD51D is not an essential factor for meiosis or reproductive development.
Nonlinear Hydrostatic Restoring of Floating Platforms
Authors: Khair Al-Solihat Mohammed , Nahon Meyer
Published: May 2014

This paper provides a comprehensive theoretical analysis to determine the nonlinear hydrostatic restoring loads and stiffnesses of a floating offshore platform. A new approach is developed to calculate the buoyancy forces and the corresponding moments for general 3D displacements of offshore platforms that utilize cylindrical floaters, such as barge (rectangular cylinder), spar, tension leg platform (TLP), and semisubmersible (circular cylinders) offshore platforms. The exact buoyancy force magnitude and point of action (center of buoyancy) and hydrostatic restoring moments for general fully coupled 3D displacements are derived. Exact expressions for the coupled water plane area restoring moments in pitch, roll, and yaw are derived in the body and inertial frames. The analysis is subsequently used to evaluate the hydrostatic loads and stiffness of floating cylinders that undergo large displacement, such as floating wind turbine (FWT) platforms. Moreover, it can be used to determine the equilibrium positions and orientation of free floating cylindrical bodies.
A Velocity Predictor–Corrector Scheme in Level Set-Based Topology Optimization to Improve Computational Efficiency
Authors: Zhu Benliang , Zhang Xianmin , Fatikow Sergej
Published: May 2014

This paper presents an optimization method for solving level set-based topology optimization problems. A predictor–corrector scheme for constructing the velocity field is developed. In this method, after the velocity fields in the first two iterations are calculated using the shape sensitivity analysis, the subsequent velocity fields are constructed based on those obtained from the first two iterations. To ensure stability, the velocity field is renewed based on the shape sensitivity analysis after a certain number of iterations. The validity of the proposed method is tested on the mean compliance minimization problem and the compliant mechanisms synthesis problem. This method is quantitatively compared with other methods, such as the standard level set method, the solid isotropic microstructure with penalization (SIMP) method, and the discrete level set method.
Clues from the brief, from the site and from the users Architectural design and soundscape
Authors: Bauer Juergen
Published: May 2014

This paper investigates how the Soundscape approach and the architectural design process can inform each other. Designing is an intuitive process and is therefore not bound by strict rules. However, most architects will agree that a successful design concept is guided by three factors: First, a design proposal needs to meet its purpose, i.e., to respond to the demands of a design brief. Second, a design proposal should contribute to its location and the surrounding neighborhood, whether it is blending into this context or emerging from it. Lastly, the actual idea for a design proposal is informed by the clues from the brief and the clues from the site. Supported by case studies, it is argued that the Soundscape approach can greatly contribute to the design process and its focus on the brief, the location, and the conceptual idea. It is further discussed how the public debate on architecture in the context of town planning and design competitions can be beneficial to the Soundscape approach and its interest in the contribution of the users and the local stakeholders.
Communicating in a cacophony: Possible solutions to the cocktail party problem in treefrog choruses
Authors: Schwartz Joshua J.
Published: May 2014

Male treefrogs advertise for mates in dense assemblages characterized by high levels of noise and acoustic clutter. Non-mutually exclusive approaches to ameliorating the “cocktail party” problem in frog choruses could involve signal production or perception. Male neotropical Dendropsophus microcephalus employ multi-note calls and can rapidly alter inter-note timing to reduce call overlap. Adjustments are made selectively such that interference is most effectively reduced among closest neighbors. There is evidence that intensity and perhaps spatial cues contribute to this selectivity. Male gray treefrogs, Hyla versicolor, do not seem to exhibit selective attention in a way that reduces call interference among nearest neighbors, and changes made in call duration and rate that occur with increasing noise levels do not aid in signal detection by females. Moreover, auditory induction, by which the auditory system might perceptually restore masked or missing elements of pulsatile calls, does not seem to occur. Although, under some circumstances, differences in call frequency may help females distinguish among neighboring males, naturalistic spectral differences do not seem to help females perceptually separate the overlapping calls of such males. There is evidence, however, that spatial separation of males can contribute to signal segregation by listening females during acoustic interference.
Low-contrast lesion detection enhancement using pulse compression technique
Authors: Mensah Serge , Rouyer Julien , Ritou Arnaud , Lasaygues Philippe
Published: May 2014

Pulse compression methods greatly improve the quality of medical images. In comparison with standard broadband pulse techniques, these methods enhance the contrast-to-noise ratio and increase the probing depth without any perceptible loss of spatial resolution. The Golay compression technique is analyzed here in the context of ultrasonic computed tomography, first on a one-dimensional target and second, on a very low-contrast phantom probed using a half-ring array tomograph. The imaging performances were assessed based on both the point spread function properties and the image contrast-to-noise ratio. The improvement obtained in the image contrast-to-noise ratio (up to 40%) depends, however, on the number of coherently associated diffraction projections. Beyond a certain number, few advantages were observed. Advances in ultrasound computed tomography suggest that pulse compression methods should provide a useful means of optimizing the trade-off between the image quality and the probing sampling density. It could also be used to accelerate the reconstruction process during the examination of patients. The results of this study also suggest that when it is proposed to search for very low contrast lesions (such as diffuse lobar carcinomas in breast cancer), once the number of projections has been set for a given tomographic set-up, the image contrast, i.e., the probability of detection, can been enhanced by using low-power, high-energy Golay sequences
The effect of crosstalk in a circular transducer array on ultrasound transmission tomography of breast
Authors: Opielinski Krzysztof J. , Pruchnicki Piotr , Roguski Wlodzimierz , Celmer Mateusz , Gudra Tadeusz , Majewski Jaroslaw , Bulkowski Mariusz , Piotrowski Tomasz , Wiktorowicz Andrzej
Published: May 2014

Various types of undesirable crosstalk can occur in ultrasonic arrays consisting of a number of elementary piezoelectric transducers. Crosstalk is a result of deficiency in electrical or mechanical isolation between array elements. It is a function of proximity between piezoelectric transducers of the array or between connections. Small piezoceramic transducers tightly located inside of a circle (cylinder or sphere in 3-D systems) are mostly used for in vivo ultrasound tomography imaging of breast tissue. This means that proper switching of transducers makes it possible to quickly acquire tomographic transmission and reflection data for all directions around the object. A problem with such arrangements is the occurrence of crosstalk, which introduce specific errors to measurement data. Transmission and reflection tomographic images reconstructed based on ultrasonic measurements with crosstalk are distorted in a characteristic way. This work analyzes the effect of crosstalk in a circular transducer array on ultrasound transmission tomography imaging—especially, when used for examination of breast tissue.
Pitch discrimination with harmonic and inharmonic tone complexes
Authors: Bramsløw Lars , Pontoppidan Niels H.
Published: May 2014

The measurement of sensitivity to temporal fine structure (TFS) in listeners can be measured by using a linear frequency-shift of a harmonic tone complex. However, the linear frequency shift of the harmonic tone complex breaks the harmonic structure, introducing a harmonic-inharmonic cue in addition to the pitch shift. In the present study, we investigated the relative contributions of frequency shift and harmonicity in normal-hearing listeners, using harmonic-harmonic, harmonic-inharmonic, and inharmonic-inharmonic shifts for unresolved tone complexes. A two-down-one-up adaptive method was used to measure the frequency shift threshold. Our results show that both inharmonic variants of the frequency shift have lower detection thresholds than the harmonic-only shift. The two inharmonic conditions are not different, indicating that the linear shift threshold is not driven by a harmonic-inharmonic cue. The effect is the same for all frequencies tested here. The results are discussed in relation to both excitation pattern and temporal fine structure models.
The role of bilingualism and musicianship on performance in a masked speech detection task
Authors: Morse-Fortier Charlotte , Pham Giang , Freyman Richard L.
Published: May 2014

Listening to an individual talker in the presence of multiple speakers is one of the most difficult auditory situations listeners encounter. Past research has shown that musicians and bilinguals have more robust neural responses to a target in a competing speech background compared to non-musicians and monolinguals, perhaps due to enhanced processing of fundamental frequency. In this study, a simple speech detection paradigm was used to minimize the effect of language comprehension while studying behavioral performance on a speech-masking task. Four groups of listeners detected English target words in the presence of two-talker babble, where all speakers were female. The task was conducted in spatial and non-spatial configurations to address conditions with low and high informational masking, respectively. The four groups tested were musicians, non-musician Asian tonal bilinguals, non-musician Spanish bilinguals, and non-musician English monolinguals. Results show that all subject groups experienced a significant release from masking in the spatial condition relative to the non-spatial condition. Musicians outperformed non-musicians in the non-spatial condition (high informational masking), but not in the spatial condition where energetic masking was presumed to dominate. Differences between the two bilingual groups and the monolingual group will be discussed. [Work supported by NIDCD 01625.]
Sleeping position can reduce the effect of snoring on sleeping partners
Authors: Yu Jen-Fang , Chen Yen-sheng , Li Hsueh-Yu , Li Li-Ang
Published: May 2014

During sleep, the sleep partner is usually the first and direct victim of snoring. When snorers make mild snoring sounds, the majority of sleep partners will tolerate the sounds. In this study, the sound stimulus of snoring was the average snoring sound of ten snorers obtained using Adobe Audition. The sleeping position of sleep partners is either to the left or right of the snorers. Therefore, in this study, the measurements were performed in a semi-anechoic room, and positions of 0 degree to 180 degrees were used to represent the sound sources of snoring. This study performed measurements of the sound field of sleep partner's sleeping positions at three distances and at angles between 0 degree and 180 degree. The results demonstrate that the difference in volume received by the two ears was the largest at a separation distance of 30 cm and an angle of 90 degree. As mentioned in previous studies, this result occurred due to the head shadow effect being more pronounced at high frequency, while the snoring in this study was a complex sound and the frequencies were mostly low.
Remote nautical bottom estimation for the safety of navigation offshore Amazon River mouth
Authors: Ren Qunyan , Hermand Jean-Pierre
Published: May 2014

In muddy areas, the fluid sediment layer can reach a level of “nautical bottom” that can contact with a ships keel causing either damage or unacceptable effects on controllability and maneuverability. Consequently, the minimum depth and allowed draught need to be determined for the safety of navigation. An acoustic remote sensing technique is proposed to facilitate navigation safety applications through the determination of sediment layer properties. It uses range and frequency-dependent features of the vertical waveguide characteristic impedance, as defined by the ratio of pressure and vertical particle velocity (or pressure gradient) at a given frequency. Such ratio can circumvent inversion uncertainty due to insufficient knowledge of complex time-varying ship noise spectrum because of its source spectral level independent. Real ship noise data recorded on a compact array offshore at the mouth of the Amazon River in Brazil, 2012, are processed by a global optimization based inversion scheme. The inverted results demonstrate that technique can estimate the effective water depth through resolving sediment layers properties, especially the density. The promising results demonstrate the feasibility of this technique to facilitate safety navigation applications at port areas.
Audio/visual concepts for human/robot communication in immersive virtual environments
Authors: Braasch Jonas , Radke Richard J. , Wen John , Si Mei , Cunningham Andrew , Keddy-Hector William , Sinha Utkarsh
Published: May 2014

Communication between robots and humans is a challenge in complex built environments. In this project, we are exploring how previous achievements in this area apply to human/robot communication within immersive virtual displays. In our concrete example, we host human-scale robots that interact with humans in our Collaborative-Research Augmented Immersive Virtual Environment Laboratory (CRAIVE-Lab). The CRAIVE-Lab provides a physical/digital environment for collaborative tasks using seamless video from multiple projectors and a 128-channel wave-field system. The system is designed to monitor the whole floor-space area (10 m × 12 m) with a camera network mounted to the ceiling grid and a microphone array combining shotgun, spherical and possibly people-worn microphones. Based on the sensor data, a visual analysis and an auditory scene analysis are performed. The latter includes sound localization, speech and musical-feature recognition. The robots, a Rethink Baxter robot mounted on an electric wheelchair and a Robokind Zeno, are used to perform assistive technology and social communication tasks. Both robots have direct access to these data using a digital feed over a wireless network to augment their own sensor systems of built-in cameras and microphones. [Work supported by NSF grant #1229391.]
Research on the parametric design of concert hall and its acoustics
Authors: Shuai Lu W. , Yan Xiang
Published: May 2014

Concert hall is a complex system containing different building elements and technical issues such as acoustics, sight, circulation, ventilation, etc. It takes designers a lot of efforts to modify the design or test its technical performance when using traditional design method. We explored the possibilities of applying parametric design method to concert hall design, developing an interactive parametric tool which could modify all the building elements according to designers' desires and functional needs, reducing designers' work burden; meanwhile, it could simultaneously show the acoustic attributes of the design, aiding to acquire a satisfactory technical performance. This paper introduces the basic framework of the parametric tool and also shows an example to demonstrate its validity.
Sub-cultural acoustical perversions and deviations: Where sensory rituals inform transcendence
Authors: Battaglia Judy E. , Banuelos Roxanne A. , Cordes Ashley L. , McRaven Amanda
Published: May 2014

This study investigated the perversions (to the normative culture that the subculture comes in contact with) and perceptions of sound in various subcultures, specifically in the Barona Band of Mission Indians and tribal subsets of rave culture. Ethnographic approaches lead us to understand alteration of sounds as a means to create a space of transcendence and liminality. Specifically, we studied the Barona Band of Mission Indians and their use of silence and sound swallowing as acoustics. Similarly, at various rave cultures, acoustic overstimulation was perceived as a key ingredient to achieving similar forms of collective effervescence. This subculture engaged in discourse likening acoustics to a variety of creative metaphors. Both sound isolation and the unique sense-making processes and speech codes of the subcultures were key to the study. Above all, we investigated the alteration of acoustics within a socio-spiritual context. In an increasingly postmodern and globalized world of tenuous connections and synchronous communication we argued for a need to put a focus on community-based subcultures in order to understand our perceptions of sound in the contemporary cultural moment.
Determining functional units of tongue motion from magnetic resonance imaging
Authors: Woo Jonghye , Xing Fangxu , Stone Maureen , Prince Jerry L.
Published: May 2014

The human tongue produces oromotor behaviors such as speaking, swallowing, and breathing, which are executed by deforming local functional units using complex muscular array. Therefore, identifying functional units and understanding the mechanisms of coupling among them in relation to the underlying anatomical structures can aid significantly in the understanding of normal motor control and the development of clinical diagnoses and surgical procedures. Magnetic resonance imaging (MRI) has been widely used to observe detailed structures in the vocal tract and to measure internal tissue motion of the tongue. This work aims at determining the functional units from tagged MRI and muscle maps are extracted from high-resolution MRI. A non-negative matrix factorization method with a sparsity constraint is utilized to extract an activation map for each tissue point using a set of motion quantities extracted from tagged MRI including information from point trajectories (i.e., displacement, angle, and curvature) and strain. The activation map is then used to determine the coherent region using spectral clustering, revealing functional units and their relations to the underlying muscles. We test our algorithm on simple protrusion and speech tasks, demonstrating that the proposed algorithm can determine the correlated patterns of the tissue point tracking trajectories and strain.
A derivation and discussion of a mutual information lower bound for dynamic acoustic response functions under a Gauss Markov law
Authors: Gendron Paul J.
Published: May 2014

A derivation and discussion of a mutual information lower bound for broadband acoustic channels under a Gauss-Markov assumption is provided. This lower bound is associated with dynamic broadband acoustic response functions that obey a Gauss Markov law. Considered here is the difference of the mutual information between source and receive signals given the acoustic response and the mutual information between acoustic response and receive signal given the source signal. The derivation illuminates the features of this mutual information and permits identifying two key information loss mechanisms. The first is an added self noise term proportional to signal power that is only associated with the innovation variance of the Gauss Markov response. The second term also increases with the innovation variance but is associated with the uncertainty in the state of the channel operator at the initial time of signaling. This later variance is identified as a forward-backward channel estimation error. Platform motion effects and their impact on these two loss mechanisms are discussed and the structure of an effective signal to noise ratio (eSNR) ceiling at high SNR are identified.
Bias and reproducibility of sound power test methods
Authors: Blevins Matthew G. , Wang Lily M. , Lau Siu-Kit
Published: May 2014

Sound power is a useful quantity in describing the strength of an acoustic source because its value is independent of distance. However, many standardized methods exist for the measurement of sound power and comparison between methods can give rise to discrepancies. An interlaboratory study was designed according to the ISO 5725 series to quantify the bias and reproducibility of three common sound power measurement methods in the HVACR industry: free field method, diffuse field method, and sound intensity method. A loudspeaker sound source was used to generate two test signals: a broadband signal with decreasing 5 dB slope per octave band, and the same broadband signal with discrete frequency tones at 58, 120, 300, and 600 Hz. The objective of the study is to quantify repeatability, reproducibility, laboratory bias, and measurement method bias, as well as investigate the influence of tones. The design of the interlaboratory study and preliminary results will be presented. The ISO 5725 methods used to investigate the sound power measurement methods in this study may be applicable to other room acoustic measurements.
Uncertainty aspects regarding the input for reverberation time predictions
Authors: Lautenbach Margriet , Vercammen Martijn
Published: May 2014

The outcome of a reverberation time prediction cannot be more accurate than the combined accuracy of input parameters. In the current procedures of measuring absorption coefficients and using them in prediction models at least two aspects regarding the accuracy of absorption coefficients are quite underexposed:(1) The precision of the measurement: the reproducibility both within one laboratory as between different laboratories or laboratory conditions; (2) The accuracy of the measurement: the dependency of the absorption coefficient on the measurement procedure in general. The upcoming ISO 354 improves both aspects by means of a more elaborate qualification procedure, the use of a reference absorber combined with a correction procedure, as well as a guidance for the extrapolation of the results to other dimensions. Still, it is interesting to think about the impact of the remaining accuracy. To what extend is an acoustic consultant “at risk” using absorption coefficients, apart from using correct modeling algorithms. Two different, but common cases, can give an idea of the influence of the accuracy, two situations in which the reverberation time heavily depends on one absorption material: a class room with an absorptive ceiling, and a concert hall with absorptive chairs.
Uncertainty in acoustic metrics due to spatial variations of the non-diffuse sound field measured in a variable acoustics classroom
Authors: Peng Zhao , Blevins Matthew G. , Wang Lily M.
Published: May 2014

Acoustic metrics are commonly expressed as single numbers in classroom acoustical designs, often neglecting the physical quantity's uncertainty due to the non-diffuse sound field in the seating area. A database of measured monaural and binaural room impulse responses (RIR) was previously gathered from a fully furnished mock-up classroom. Different wall and ceiling absorption configurations were used to alter the mid-frequency reverberation times (RT) in five scenarios between 0.4 and 1.1 s. The middle three RT scenarios were additionally created from two different material configurations. For each material configuration (eight in total), two furniture orientations were utilized. RIRs were measured at 9 to 10 receiver positions for each material/furniture configuration to document the spatial variation in the resulting sound field. Diffuseness has been calculated for each receiver position utilizing the measured RIRs by following Hanyu's (2013) method using normalized decay-canceled impulse responses. Variations in diffuseness and in the assorted acoustic metrics calculated from the measured RIRs are investigated across different receiver positions. These acoustic metrics, pertinent to classroom acoustical designs, include RT, speech transmission index, clarity, and interaural cross-correlation. Means to quantify uncertainty in these metrics due to spatial variation in the non-diffuse sound field will be discussed.
Dynamics of biosonar signals of free swimming dolphins searching for bottom targets
Authors: Au Whitlow W. , Copeland Adrienne , Martin Stephen W. , Moore Patrick W.
Published: May 2014

Measuring on-axis biosonar signals from a free swimming dolphin performing a sonar task is extremely difficult without having a special device that the animals carry. A bite-plate device which had a hydrophone directly in front of the dolphin at a fixed location along the beam axis of the biosonar beam was constructed as a part of the Navy Marine Mammal Research Program in San Diego. A data acquisition and storage unit was a part of the Biosonar Measurement Toolbox (BMT) and hung below the bite plate. The outgoing signal was measured by the omnidirectional hydrophone while two disk hydrophones measured the echoes. The device was used with two Atlantic bottlenose dolphins (Tursiops truncatus) as the animals conducted biosonar searches for specific objects on the ocean bottom. The outgoing signals were parameterized into the following, peak-to-peak source levels, source energy flux density, center frequency, rms bandwidth, rms duration, and interclick intervals. The parameters were analyzed with both a cluster analysis and a principle component analysis to determine the grouping of the parameters and the relationship between parameters. Both dolphins used different biosonar search strategy in solving the problem and their biosonar signals reflect the difference in strategy.
Target shape perception and clutter rejection use the same mechanism in bat sonar
Authors: Warnecke Michaela , Simmons James A.
Published: May 2014

Big brown bats (Eptesicus) emit multiple-harmonic FM sounds (FM1, FM2) and exploit the relative weakening of higher harmonics in lowpass echoes from the surrounding scene to suppress clutter by defocusing of wideband images. Only echoes from a frontally located targets arrive as unfiltered, focused images. Experiments using electronically generated echoes show that lowpass filtering of masking echoes causes clutter masking to disappear. Lowpass filtering induces amplitude-latency trading, which retards response times at higher frequencies in clutter echoes relative to lower frequencies. Introducing countervailing changes in presentation-times of higher frequencies in electronically generated clutter echoes restores masking. In the big brown bat's inferior colliculus, FM sounds mimicking broadcasts and echoes evoke ~1 spike per sound at each neuron's best frequency; however, amplitude tuning is very broad. To exploit their high acuity for detecting coherence or non-coherence of echo responses, bats work in the latency domain instead, removing background objects through deliberate imposition of response de-synchronization and concomitant inattention on undesired clutter. Overall, the results indicate that big brown bats use neuronal response timing for virtually all auditory computations of echo delay, including clutter rejection. This use of active perceptual processes in biosonar instead of conventional sonar processes opens a new view toward biomimetic design.
Passive mapping of acoustic sources within the human skull cavity with a hemispherical sparse array using computed tomography-based aberration corrections
Authors: Jones Ryan M. , O'Reilly Meaghan A. , Hynynen Kullervo
Published: May 2014

Traditionally, the use of ultrasound (US) in the brain has been limited by the skull bone, which presents unique challenges for both transcranial therapy and imaging due to its attenuating and aberrating effects, which become more prevalent at higher US frequencies. On transmit, these skull-induced aberrations can be overcome through the use of large-aperture phased array transducers with appropriate driving frequencies, combined with computed tomography (CT)-based bone morphology and numerical models to derive element driving signals which minimize the distortions. Recently, we have demonstrated in silico that an analogous approach can be performed during beamforming on receive, to allow for passive acoustic imaging over a large region within the skull cavity [Jones et al., Phys. Med. Biol. 58, 4981–5005 (2013)]. We will present preliminary results obtained from applying this technique experimentally with a hemispherical (30 cm diam.) sparse receiver array (128 piezo-ceramic elements, 2.5 mm diam., and 612 kHz center frequency) to image acoustic sources through an ex vivo human skullcap. Images produced using non-invasive CT-based skull corrections will be compared with those obtained through an invasive hydrophone-based correction approach, and with images formed without skull-specific corrections. This technique has promising applications in both cavitation-mediated transcranial focused ultrasound therapies, by providing a method for treatment monitoring and control, as well as in ultrasound angiographic imaging of the brain.
Conformal cymbal array: A broadband, wide beamwidth underwater acoustic projector
Authors: Tressler James , Houston Brian H.
Published: May 2014

The development of “cymbal”-based acoustic source technology in recent years has been an essential advancement in improving NRL's capability for shallow-water acoustics. The cymbal's unique attributes of high acoustic output from a lightweight, thin profile configurable array is a central technology in target identification programs at NRL. This talk will present a review of cymbal array development over the past ten years. It will start with conventional piezoelectric ceramic (PZT) cymbal elements and end with current research on advanced cymbal designs utilizing new formulations of piezoelectric single crystal materials. In particular, the contributions of Kim Benjamin to the initial development work of the conformal array design will be highlighted. [Work sponsored by the Naval Research Laboratory.]
The science of art, the art of science
Authors: Krishnamurthy Rohan
Published: May 2014

I will discuss how my passion for the arts and sciences originated in and developed since elementary school, and led me to my present work as a professional percussionist, educator, researcher, and entrepreneur. Throughout high school, I pursued music and science projects in parallel. My dual interests encouraged me to pursue a double major in music and chemistry at Kalamazoo College. My senior thesis introduced me to acoustical research when I worked with Dr. James Cottingham at Coe College to study the acoustics of a new drum tuning system that I invented and patented. I presented my research at ASA 2007 in New Orleans and other research at subsequent ASA conferences. After finishing college, I pursued a doctorate in musicology at the Eastman School of Music at the University of Rochester. I will discuss specific examples of my past and current interdisciplinary projects, and how my association with the ASA continues to inspire my endeavors.
Robotics, free-reed instruments, and naughty birds: Finding the common thread
Authors: Dieckman Eric A.
Published: May 2014

Musical acoustics often provides an accessible starting point for undergraduate research in which the basics are learned and applied to interesting problems. Even if students later study other areas of acoustics, the research experience gained is invaluable. This presentation will touch on a number of research projects encountered since the author's 2006 award for investigations of the acoustic behavior of Southeast Asian free-reed mouth organs. These projects come from a wide variety of acoustic disciplines, from nondestructive evaluation and architectural acoustics to benign bird exclusion and acoustic sensors for mobile robots, with the common thread of signal processing providing a focal point.
Kenneth McKechnie Eldred—A distinguished noise control engineer I
Authors: Lang William W. , Maling George C.
Published: May 2014

Elected in mid-career in 1975 to the U.S. National Academy of Engineering (NAE) “For outstanding accomplishments in noise and vibration control of air, space, and transportation vehicles and in delineating acceptable noise environments for people.” His NAE peers recognized him “...as one of the five best noise and vibration control engineers in the country.” Ken's first job after graduating from M.I.T. in 1950 with studies of advanced courses in acoustics was as head of the Boston Naval Shipyard's lab working on the reduction of the noise and vibrations of submarine auxiliary equipment. In 1953 on active duty in the U.S. Air Force, he became Chief of the Bio-Acoustics Branch, Wright Air Development Center. In 1957, he moved to California for a career with Western Electro-Acoustic Laboratory and Wyle Laboratories prior to joining Bolt Beranek and Newman. This paper is primarily devoted to his activities in support of INCE/USA, his role in the passage of the Noise Control Act of 1972, and his activities in connection with the Office of Noise Abatement and Control in the U.S. Environmental Protection Agency.
Resonance ultrasound spectroscopy for studying piezoelectricity and internal friction at elevated temperatures of quartz, langasite, and gallium nitride
Authors: Ogi Hirotsugu , Ledbetter Hassel
Published: May 2014

Resonance ultrasound spectroscopy (RUS) is a powerful method for measuring elastic constants (Cijkl) of solids. It can be applied to determine the piezoelectric coefficients (eijk) as well, because they also affect the mechanical resonance frequencies. Precise frequency measurements in vacuum and unambiguous mode identification with laser-Doppler interferometry allowed us to determine Cijkl and eijk simultaneously for crystals including alpha quartz, which shows low piezoelectricity. We further developed a noncontact excitation and detection method with antennas through electromagnetic fields and study internal friction and carrier mobility of quartz, langasite, and GaN at elevated temperatures up to ~1200 K. This method is also successfully applied to developing ultrahigh-sensitive biosensors for diagnosis.