bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomic selection allowing for marker‐by‐environment interaction
Authors: Schulz‐Streeck Torben , Ogutu Joseph O. , Gordillo Andrés , Karaman Zivan , Knaak Carsten , Piepho Hans‐Peter
Published: October 2013

Genomic selection has been routinely implemented in plant breeding in two stages. The first stage usually omits the marker information and estimates adjusted means of genotypes across environments. The second stage uses the adjusted means to predict genomic breeding values. However, if the effects of markers vary substantially between different environments, it may be important to account for this variation for varieties adapted to different environments. Using two maize data sets, we investigated whether modelling the marker‐by‐environment interaction can improve the predictive ability of genomic selection relative to modelling genotype‐by‐environment interaction alone. Modelling the marker‐by‐environment interaction did not substantially increase the predictive ability relative to modelling only the genotype‐by‐environment interaction for the two tested data sets. Thus, genomic selection, carried out in a stagewise fashion, such that the marker information is omitted until the last stage of the process, may suffice for most practical purposes. Moreover, predictive ability did not reduce substantially even when the number of markers with consistent effects across environments used for genomic prediction was reduced to about 50.
CostalBCGosteomyelitis developing 1 year afterBCGvaccination
Authors: Oyachi Noboru , Obana Kazuko , Suzuki Takeyuki , Kimura Shuri , Chino Kozo , Oyama Toshio , Takano Kunio
Published: October 2013

Reported here is the case of a 15‐month‐old boy with costal osteomyelitis due to the bacillusCalmette–Guérin (BCG) vaccine against tuberculosis. Mild complications of this vaccine, such as localized abscess and regional lymphadenitis, are occasionally recognized, but its association with osteomyelitis is extremely rare.
Thrombolytic therapy in Kawasaki disease: A report of four cases
Authors: Harada Mana , Akimoto Katsumi , Otaka Masao , Sato Keiko , Oda Hisayuki , Otsuki Masahiro , Takahashi Ken , Kishiro Masahiko , Shimizu Toshiaki
Published: October 2013

Four patients with a thrombus in a coronary artery aneurysm due to Kawasaki disease (KD) were treated at our hospital between 1994 and 2009. All the cases were treated with intravenous coronary thrombolysis (IVCT) therapy and the cases with acute myocardial infarction were treated with additional intracoronary thrombolysis therapy. Although both thrombolytic therapies were effective, IVCT required more time than intracoronary thrombolysis to resolve the thrombus. We concluded that IVCT can be used as the first‐line thrombolytic therapy for KD, except in cases with acute myocardial infarction.
Post‐streptococcal acute glomerulonephritis associated with pneumococcal infection
Authors: Hibino Satoshi , Hoshino Akihiro , Fujii Takanari , Abe Yoshifusa , Watanabe Shuichiro , Uemura Osamu , Itabashi Kazuo
Published: October 2013

Streptococcus pyogenes is the most common cause of post‐infectious glomerulonephritis. Described herein is the case of a 5‐year‐old girl with febrile post‐streptococcal acute glomerulonephritis (PSAGN) associated with pneumococcal bacteremia. The chief complaints were fever and macrohematuria without respiratory symptoms. Urinalysis indicated a protein level of 3+. Serological data showed elevated anti‐streptolysin O (ASO) and hypocomplementemia. Blood culture was positive for S. pneumoniae. Her acute renal failure was mild and improved over several days. Although PSAGN was confirmed by elevated ASO and transient hypocomplementemia, the clinical course was consistent with those of several reported cases of AGN associated with pneumococcal infection. To our knowledge, there have been few reports on the relationship between pneumococcal infection and the incidence of PSAGN. We suggest the hypothesis that pneumococcal infection itself could exaggerate the complement reaction leading to PSAGN. It is important to consider PSAGN associated with a microbial infection such as S. pneumoniae when faced with a febrile patient with AGN.
Anaplastic sarcoma of the kidney: Case report and literature review
Authors: Watanabe Noriko , Omagari Daisuke , Yamada Tsutomu , Nemoto Norimichi , Furuya Takeshi , Sugito Kiminobu , Koshinaga Tsugumichi , Yagasaki Hiroshi , Sugitani Masahiko
Published: October 2013

Anaplastic sarcoma of the kidney (ASK) is a relatively newly recognized pediatric renal tumor. The present patient, a 13‐year‐old boy with a large renal mass, underwent surgery. Pathological findings showed proliferation of short spindle‐shaped cells with anaplastic features including multiple foci in hyaline cartilage. Complex chromosomal abnormalities were detected in the tumor cells. Postoperative chemotherapy with the regimen for Ewing's sarcoma achieved complete remission but the tumor recurred and the patient died during re‐induction chemotherapy. Autopsy indicated the cause of death as duodenal hemorrhage. Because there were no viable tumor cells, the recurrent tumor was considered to have been completely cured by chemotherapy. ASK is a very rare tumor, of unknown pathogenesis, and no standard treatment has yet been established, but the tumor cells may be responsive to chemotherapy. Further study is needed to establish the optimal treatment strategy.
JNK1 and JNK2 regulate α‐SMA in hepatic stellate cells during CCl4‐induced fibrosis in the rat liver
Authors: Hong Il‐Hwa , Park Sang‐Joon , Goo Moon‐Jung , Lee Hye‐Rim , Park Jin‐Kyu , Ki Mi‐Ran , Kim Sang‐Hyeob , Lee Eun‐Mi , Kim Ah‐Young , Jeong Kyu‐Shik
Published: October 2013

Following liver injuries, hepatic stellate cells (HSCs) express α‐SMA. Mitogen activated protein kinase (MAPK) signaling pathways mediate α‐SMA expression in distinct cell types. However, the regulation of α‐SMA expression by MAPKs in HSCs has been rarely studied. We aimed to study the role of MAPKs in the activation of HSCs during liver fibrosis. Liver fibrosis of rats was induced by carbon tetrachloride. HSC‐T6 cells, murine embryonic fibroblasts, JNK1−/− and JNK2−/− cells were used for in vitro studies. Immunohistochemistry and immunoblot analysis were used. We have found that the expression of JNK and α‐SMA co‐localized in HSCs during liver fibrosis, but ERK and p38 expressed in macrophages. The expression of α‐SMA was up‐regulated by JNK1 and JNK2 in non‐stress condition. Under TGF‐β stimulation, however, the level α‐SMA expression was increased by only JNK1, but not significantly changed by JNK2. We suggest that JNKs are responsible for α‐SMA regulation, and especially JNK1 has a major role in up‐regulation of α‐SMA expression in HSCs under stress condition induced by TGF‐β during liver fibrosis.
Epithelioid hemangioendothelioma with extensive cystic change and CAMTA1 rearrangement
Authors: Lee Seung Eun , Park Ha young , Kim Seokhwi , Bang Heejin , Min Ji Hye , Choi Yoon‐La
Published: October 2013

Epithelioid hemangioendothelioma (EHE) is a rare vascular neoplasm that has the ability to recur locally and metastasize. Thus, it is important to distinguish this tumor from other epithelioid vascular neoplasms. A 47‐year‐old man presented to our hospital with a pelvic mass with severe ischialgia and weight loss. Surgical resection was performed, and the mass was found to have dark red multiloculated cysts with hemorrhage and calcification. The histopathologic examination showed a central sclerotic, hypocellular zone and a peripheral cellular zone. Only the peripheral portion of the wall revealed nested tumor cells in light blue myxoid stroma. These tumors are typically composed of short strands or cords of bland epithelioid cells with occasional intracytoplasmic lumens embedded in a myxohyalinized stroma. The tumor cells were positive for CD31 and CD34 and negative for factor VIII‐related antigen, CK (AE1/AE3) and S‐100. The tumor nuclei showed distinct break‐apart signals with individual green and/or red signals, indicating the presence of CAMTA1 rearrangement. In this study, we report a case of EHE that was difficult to diagnose based on histology alone. Therefore, we also performed fluorescence in situ hybridization, and found that the tumor harbored a CAMTA1 gene rearrangement, which confirmed the diagnosis.
Measuring Gender Disparity in the HIV Pandemic: A Cross‐National Investigation of Female Empowerment, Inequality, and Disease in Less‐Developed Nations
Authors: Austin Kelly F. , Noble Mark D.
Published: October 2013

Current research recognizes that the HIV pandemic uniquely impacts women, as they are socially and biologically more vulnerable to the infection. However, present measurement strategies focus on assessing the level of HIV infection among women, rather than inequality in the distribution of HIV cases by gender in less‐developed nations. In this study, we compare the cross‐national determinants of the level of female HIV prevalence to the determinants of the percentage of HIV cases among women. Ordinary least squares (OLS) regressions suggest that the predictors of female HIV differ across the two measures, where aspects of female empowerment and female access to health resources are more influential in explaining the distribution of HIV cases across gender than the level of female HIV prevalence. These results suggest that analyzing the distribution of HIV cases by gender is a more appropriate way to measure gender disparities in the HIV pandemic. Therefore, future research should be cautious to consider the implications of investigating levels of HIV versus the distribution of HIV cases across populations.
Erythrocyte dysplasia in peripheral blood smears from 5 thrombocytopenic dogs treated with vincristine sulfate
Authors: Collicutt Nancy B. , Garner Bridget
Published: October 2013

Secondary dyserythropoiesis has been associated with vincristine administration in dogs. Evaluation of bone marrow aspirates for the presence of morphologic abnormalities in the erythroid lineage aids in the diagnosis. However, morphologic features of circulating erythroid precursors in these cases have not been described previously. The purpose of this report was to describe the cytologic features of dyserythropoiesis in peripheral blood and also bone marrow smears in a case series of dogs with immune‐mediated thrombocytopenia (IMT) treated with vincristine sulfate. Nineteen dogs receiving vincristine for treatment ofIMTwere identified by retrospectively searching a computerized medical record system. There were 5 dogs that had dysplastic erythroid precursors in peripheral blood smears within 7 days of vincristine treatment. Two of those 5 dogs also had evidence for erythrodysplasia in modified Wright's‐stained bone marrow smears obtained postvincristine administration. Morphologic changes included bizarre or inappropriate mitotic figures, abnormal nuclear configurations (fragmentation, elongation, indentation, and binucleation), atypical nuclear remnants (Howell‐Jolly bodies), or nuclear and cytoplasmic asynchrony within the erythroid precursors. A brief review of the literature with discussion of the etiologies for dyserythropoiesis is provided. The dyserythropoiesis was clinically insignificant in all 5 cases and resolved. However, pathologists and clinicians should be aware of these potential findings to prevent misdiagnosis of other conditions.
An innovative synthetic tissue-mimicking material for high-intensity focused ultrasound
Authors: Lafon Cyril , Sapozhnikov Oleg A. , Kaczkowski Peter J. , Vaezy Shahram , Noble Misty , Crum Lawrence A.
Published: October 2013

A dosimetry study of the high-temperature and pressure regimes involved in high-intensity focused ultrasound (HIFU) requires experiments on biological tissues because no synthetic tissue-mimicking phantom is available. Unfortunately, the development of coagulative lesions cannot be observed in real-time in opaque tissues. Furthermore, the natural heterogeneous structure of tissue complicates direct comparison with numerical models. In this study, a new optically transparent phantom is evaluated. It is principally composed of a polyacrylamide gel, and includes a thermally sensitive indicator protein that becomes optically diffusive when denatured. Various tests were undertaken to characterize the acoustical, thermal, and optical properties of this material for a range of protein concentrations. The attenuation coefficient can be usefully modified by adjusting the quantity of embedded proteins to permit some selection of acoustic regime. It is also possible to emphasize cavitation activity at lower BSA concentrations, or thermal effects at higher concentrations. This new phantom adequately matches tissue for most of the measured parameters and facilitates the study of the HIFU bioeffects. [Work supported by ONR Grant No. N00014-96-1-0630 and NIH Grant No. HL64208-02.]
Quantification of submicron DDFP gas bubbles using 30 MHz backscattered ultrasound
Authors: Everbach E. Carr , Roy Ronald A. , Flaherty John T.
Published: October 2013

To determine the size distribution of microbubbles following a temperature-induced phase change of dodecafluoropentane (DDFP) emulsion particles, the acoustic backscatter was measured in 2 μs duration tonebursts of 30 MHz ultrasound from individual bubbles present in the emulsion as it moved in a coaxial jet flow at 20°C and 37°C [R. A. Roy and R. E. Apfel, ‘‘Mechanical characterization of microparticles by scattered ultrasound,’’ J. Acoust. Soc. Am. 87, 2332–2341 (1990)]. DDFP liquid emulsion droplets would be expected to undergo a phase change to gaseous microbubbles above the DDFP boiling point of 28–30°C at atmospheric pressure. Calibration of the backscatter coefficients for the system was accomplished using 6 micron diameter polystyrene spheres. The DDFP bubbles were assumed to be small enough to behave isothermally and viscosity−dominated in their dynamics [D. Khismatullin and A. Nadim, ‘‘Radial oscillations of encapsulated microbubbles in viscoelastic liquids,’’ Phys. Fluids, submitted]. The results yielded a bubble size distribution for the emulsion of between 50 and 100 nm radius with a mean radius of 75 nm at 37°C. [Work supported by a grant from Sonus Pharmaceuticals, Inc.]
An overview of time-reversed acoustics
Authors: Fink Mathias
Published: October 2013

Time-reversal invariance is a very powerful concept in classical and quantum mechanics. In the field of acoustics, where time-reversal invariance also occurs, time-reversal experiments may be achieved simply with arrays of transmit–receive transducers, allowing an incident acoustic field to be sampled, recorded, time-reversed, and re-emitted. The time-reversal mirrors (TRMs) are innovative tools in the field of fundamental physics. They may be used to study random media, multiple scattering processes, chaotic scattering, inverse scattering problems, dissipation effects, and diffraction limits. They open the way to new signal processing. An overview of these fields will be presented. Applications of TRMs will also be described, including underwater acoustics, medical applications, telecommunications, as well as nondestructive testing.
An overview of the D.O.R.T. method
Authors: Prada Claire
Published: October 2013

This talk will review the decomposition of the time reversal operator (D.O.R.T.) method. This new approach to active detection and focusing of acoustic waves using arrays of transmitters and receivers allows selecting and focusing on scatterers through complex media. The method was derived from the theoretical analysis of iterative time reversal mirrors. It consists essentially in the construction of the invariants of the time reversal process. The diagonalization of the time reversal operator provides both a measure of the strength of a scatterer and the phase law that can be applied to the array to focus selectively on a scatterer. After explaining the principle of the D.O.R.T. method several experimental results will be shown.
Nonlinear acoustics of phase conjugate ultrasound waves
Authors: Brysev A. P. , Krutyansky L. M. , Hamilton M. F. , Pernod P. , Preobrazhensky V. I.
Published: October 2013

Nonlinear propagation of phase conjugate waves (PCW) in liquid is studied experimentally and simulated numerically. A supercritical parametric technique is used for ultrasonic (5–10 MHz) wave phase conjugation (WPC) with enormous amplification (more than 80 dB). The technique provides sufficient PCW intensity for vivid manifestation of acoustic nonlinearity. Quantitative studies of refocused PCW beams have been performed. The space–time structure of nonlinear PCW was measured and results were compared with calculations. Finite aperture size and conjugator gain were taken into account in a numerical model based on the nonlinear parabolic wave equation. Accurate refocusing of strongly nonlinear PCW beams is demonstrated for sufficiently large apertures. The second and higher harmonics generated by PCW are localized within the focal region of the incident wave even after PCW refraction in a randomly inhomogeneous medium. The phenomenon is explained theoretically by phase locking of PCW harmonics in nondispersive acoustic media. The results have been generalized to include narrow-band WPC of selected harmonics of the incident wave when the latter is nonlinear. Specifically, WPC can both remove phase distortion and amplify the second harmonic sufficiently that imaging can be performed with the resulting fourth harmonic. This novel imaging technique is demonstrated in an example of C-scan acoustic microscopy.
DORT applied to active sonar
Authors: Fromm David M. , Gaumond Charles F.
Published: October 2013

The decomposition of the time reversal operator (DORT) is a single frequency method of spatially isolating scatterers with a multiple-source/multiple-receiver system [C. Prada et al., J. Acoust. Soc. Am. 99, 2067–2076 (1996)]. The application of the DORT technique to a broadband sonar system is explained by showing its relationship to the sonar equation. The orthogonal matrices are related to source and receiving steering vectors and the singular values to the echo levels of the various signal components. The structure of a coherent, reverberation-limited, broadband, numerical sonar model is shown. Numerical results from this sonar model are processed by windowing and Fourier transforming. Then DORT is applied and the depth isolated target components are identified through projecting source and receiver steering vectors with modeled propagation matrices. The ability of this procedure to isolate scatterers from distributed bottom reverberation is shown for a set of source/receiver geometries with the scatterer at various depths and ranges. Both range-independent and range-dependent environments are considered. [Research sponsored by ONR.]
Time-reversal acoustics and maximum-entropy imaging
Authors: Berryman James G.
Published: October 2013

A common problem in acoustics imaging is target location using either passive or active data inversion. Time-reversal methods in acoustics have the important characteristic that they provide a means of determining the eigenfunctions and eigenvalues of the scattering operator for either of these two cases. Each eigenfunction may often be approximately associated with an individual scatterer. The resulting decoupling of the scattered field from a collection of targets is a very useful aid to localizing the targets, and suggests a number of imaging and localization algorithms. Two of these are linear subspace methods and maximum-entropy imaging.
Acoustic wavefront modeling in shallow water
Authors: Tindle Chris T.
Published: October 2013

Wavefront modeling offers a direct method of finding pulse waveforms in shallow water and allows for both ocean surface waves and variable water depth. The wavefront is found by tracing rays to a fixed range and finding the ray depth as a function of starting angle. Interpolation on the wavefront provides the amplitude and arrival time at the receiver depth. Phase is determined by the ray history. Surface waves can lead to focusing with cusps and caustics in the wavefront. Near cusps and caustics the field is found by numerically fitting a phase function with the appropriate number of saddle points. Model results are compared with field measurements. [Work supported by ONR.]
Three-dimensional Gaussian beam tracing for shallow-water applications
Authors: Baxley Paul A. , Bucker Homer , McDonald Vincent K. , Porter Michael B.
Published: October 2013

Gaussian beam tracing is a ray-based method of acoustic wave propagation that overcomes some of the implementation problems of conventional ray methods, while retaining a speed advantage over wave theory approaches. A fan of Gaussian beams are propagated from a source, according to the standard ray equations, so that the pressure at any given point can be approximated by the sum of contributions from each beam. Eigenray computations, perfect shadows, and infinite caustics associated with standard ray methods are thereby eliminated, and the applicability to lower-frequency problems is improved. Gaussian beam tracing is particularly well suited for three-dimensional problems, for which eigenray computations are costly. The effectiveness of a three-dimensional Gaussian beam model [Bucker, J. Acoust. Soc. Am. 95, 2437–2440 (1994)] for predicting acoustic propagation in shallow water is demonstrated. At low frequencies, Gaussian beam and wave solutions are compared for the ASA benchmark wedge problem and the Shallow Water Acoustic Modeling 1999 Workshop Gaussian canyon problem. The use of the model for the analysis of three-dimensional bathymetric effects in real data will also be demonstrated. At high frequency, model predictions of impulse responses will be compared to measured data for a number of acoustic communications experiments. [Work supported by ONR.]
A rational approximation for the parabolic equation method
Authors: Lu Ya Yan
Published: October 2013

The parabolic equation method typically uses rational approximations to the square root operator. The split-step Padé method of Collins is more efficient and it uses rational approximations of the propagator—the exponential of the square root operator, say P=expis√1+X. Previously, only approximants of the type [p/p] are used. In order to damp the evanescent modes (and avoid instabilities), these [p/p] approximants are not the simple [p/p] Padé approximant of P. In this talk, we demonstrate that [p/(p+1)] Padé approximant of P can be used in the split-step Padé method. It is simple to construct and it has a good accuracy for approximating the propagating modes, yet it is guaranteed to suppress the evanescent modes. This approach will be compared with other variants of the split-step Padé method in numerical examples for acoustical waveguides.
Joint channel and Doppler estimation via low-complexity prior
Authors: Gendron Paul , Yang T. C.
Published: October 2013

Joint estimation of channel impulse response and Doppler drift can be confounding since source motion and media temporal fluctuations can be misidentified. In addition, multipaths can be associated with different though not independent Dopplers. We present a novel algorithm for joint estimation of channel impulse response and mean Doppler drift by assuming prior constraints that favor lower complexity of the posterior model. The resulting estimator is compared with the popular maximum likelihood estimator (MLE). Approximate posterior covariance estimates provide Doppler/channel correlation and confidence bounds. We test this method with synthetic channel data and experimental data from a shallow water environment and compare the method with the classical MLE.
Characterization of temporal fluctuations of broadband channel impulse functions within communication packets
Authors: Yang T. C. , Gendron Paul
Published: October 2013

Temporal fluctuations of an acoustic channel can be characterized by the amplitude and phase fluctuation statistics of individual multipath arrivals, and the temporal coherence of the channel. At low frequencies where the temporal coherence time is much longer than the duration of the probing pulse, the measurements of the fluctuation statistics and channel coherence functions were straightforward and can be found in previous publications. As frequency increases to tens of kHz or above, the coherence time can be shorter than the packet length used in acoustic communications (acomms). Under such circumstances, the channel coherence can impede the equalizer performance and measurement of the temporal evolution of the channel within the duration of a packet (the intra-packet coherence) is critical for modeling the acomms performance. In this paper we report the measurements of intra-packet coherence and multipath fluctuation statistics from two at-sea experiments using M-sequence signals having sequence length much shorter than the acomms packet length. Initial analysis results associated with fixed–fixed and moving-drifting source–receiver configurations will be presented. [Work supported by ONR.]
Overhead localization in a hall with oval plan, and its practical solution
Authors: Okano Toshiyuki
Published: October 2013

This report concerns an unusual localization phenomenon that was observed on the center line of a hall having an oval plan. The hall, recently completed in Tokyo with 760 seat capacity and one balcony, is used primarily for chamber music. After installation of audience seats, a troublesome overhead localization was observed at listener positions on the fore–aft center line whenever the source was also on the center line. Listening tests at the site indicated that the locations from which the unwanted reflections appeared to originate were the following parts: (a) two opposite portions of the concave side walls just below the ceiling; (b) main-floor rear side walls; and (c) a portion of the main-floor rear wall. It was demonstrated that temporarily covering those surfaces with sound absorbing material could drastically reduce the overhead localization. In order to avoid seriously decreasing the reverberation time, a minimum amount of added sound absorption was a necessity. Tests in the laboratory demonstrated that the absorbing areas on part (b) would be minimized if installed asymmetrically. The final result rendered the localization phenomenon and some on-stage rear-wall echo inaudible when sound absorbing materials were permanently applied.
A revision of the accepted criteria for the distribution of the resonance frequencies of rectangular rooms
Authors: Moscoso Richard A. , Vasquez Caleb
Published: October 2013

There are several criteria to predict to good or bad mode distribution in function of the proportion between the dimensions of a rectangular enclosure. The principals are the criterion of Bolt and the criterion of Bonello. Both, do not demand a fix relationship between the proportions of an enclosure, but rather permit a wide range of combinations between them. To generate an adequate distribution of modes so that the coloration will be void or at least be the minimal possible is necessary to take in account the reverberation time. The criterion of Bolt is independent of the enclosure reverberation time. The criterion of Bonello has an improvement respect to the criterion of Bolt because it is sensible to the volume changes, but it is not directly related to the reverberation time. The present work shows the procedure to obtain the theoretical reverberation time to avoid coloration in a rectangular enclosure, analyzing the modal spectral density in 1/3 octave bands. This is critical in studio control rooms and studio recording rooms.
Ultrasonic technique spectram tomography
Authors: Kobayashi Kazuto , Otuki Sigeo
Published: October 2013

This is a study about a technique for distinguishing a speckle pattern by a fine structure of a size of about wavelength of the observation waves from a large structure image. Speckle pattern is the one of the major factors that disturbs the observation of fine structure. It is generated by interference caused from spacious frequency factor and not by existence of the object. This echo image forming apparatus comprises: a wave transmitter for transmitting an observation wave pulse of a wide band; a wave receiver for receiving an echo of the observation wave pulse transmitted to generate a reception signal; a filter for extracting signal components of a plurality of different frequencies predetermined from the reception signal obtained by the wave receiver; and a display device for imaging separately, respectively, the signal components of each frequency extracted by the filter and displaying images corresponding to resultant frequencies mutually relating to each other. The signal components of the plurality of frequencies predetermined are extracted from the reception signal of the wide band by use of the filter. The speckle patterns by the fine structure of about wavelength in correspondence with the corresponding frequency emerge respectively in each extracted frequency component.
Spectral characteristics of the sound generated by ultrasound imaging systems in the human body
Authors: Fatemi Mostafa , Ogburn Paul L. , Greenleaf James F.
Published: October 2013

Medical ultrasound scanners use high-energy pulses to probe the human body. It can be shown that the radiation force resulting from the impact of such pulses to the object can vibrate the object, producing a localized high-intensity noise in the audible range. When the scanner is used in a maternal examination, and the beam is directed toward the fetal head, this noise can disturb the fetus and cause it to move vigorously [J. Ultrasound Med. 20, 883–889 (2001)]. Here, a theoretical model for the audio noise generated by ultrasound scanners is presented. This model describes the temporal and spectral characteristics of the noise. It has been shown that the noise has rich frequency components at the pulse repetition frequency and its harmonics. Experiments have been conducted in a water tank to measure the noise generated by a clinical ultrasound scanner. Results indicate that the noise pressure level at the focal point of the ultrasound beam on a reflective object can reach up to 120 dB relative to 20 μP. This result is in agreement with the theoretical predictions. The noise was also measured in a human uterus, indicating intensities in the range of 90–100 dB.
Computer modeling of swallow using acoustic measures
Authors: McKaig T. Neil
Published: October 2013

Although cervical level auscultation of the human swallow has long been discussed as a potential adjunct to the clinical dysphagia examination, there has been little research to quantify the acoustic parameters of the procedure. After initially examining the relative timing of these events in a normal population of +250 subjects, algorithms capable of generating computer models based on relative timing of acoustic data were developed. Procedure: In addition to physiological profile and medical/social history, a sample swallow is recorded and 6 raw measurements data points are identified: initiation of deglutition apnea (dA), leading and trailing edges of both the initial and secondary bursts as well as the terminal acoustic event. From this an additional seven measurements are derived: duration of dA, relative midpoint of dA, durations and midpoints of initial and secondary bursts, the interburst duration, and the relative midpoint of the bolus transport signal (BTS). Conclusion: It is possible for the computer to generate an optimal swallow profile for an individual and through statistical analyses predict the range, median and relative timing for each event reporting profile and the degree of confidence based on the subset n. [Equipment for capturing data and computer analysis provided by Welsh/Allyn Corporation.]
Interactive web-based software for musical technology
Authors: Boye Daniel
Published: October 2013

A general course covering digital music basics, electronic synthesis of musical instruments, room acoustics, CD and DVD players, and compressed data formats has been developed to draw upon the penchant of college students for music and computer technology. Nonscience majors populate this course at Davidson College to satisfy an elective or a core requirement in the traditional liberal arts curriculum. Students directly apply material covered in the course to daily experiences and to musical performances they are required to attend. This presentation will briefly describe the course structure and focus on several interactive web-based sound exercises and demonstrations that examine acoustical and psychoacoustical phenomena. Interactivity is achieved through the use of Java-based Physlets (developed at Davidson), JavaScript, and streaming of audio clips. Currently available time and frequency domain visualization plugins for popular media players (Windows Media Player, WinAmp), while imaginative and colorful, do not lend themselves to scientific measurement. New measurement-friendly visualization plugins are being developed at Davidson. These plugins will be described and made available for download.
Evolution of teaching and research at CCRMA
Authors: Chafe Chris
Published: October 2013

Three decades of research at the Center for Computer Research in Music and Acoustics have been accompanied with an evolving program for teaching music science and technology. As new understanding and new tools advance the research, a growing set of methods and skills need to be covered. The heavy emphasis on ‘‘project-based’’ teaching at CCRMA crosses several subdisciplines and serves students with a wide range of backgrounds and levels of experience. One thing has been constant throughout the program’s existence: surprises happen in teaching. The talk will conclude with a description of ingredients that help encourage serendipitous results at the lab.
Acoustics, Audio, and Music Technology Education at the University of Illinois at Urbana-Champaign
Authors: Beauchamp James W. , Taube Heinrich , Tipei Sever , Wyatt Scott A. , Haken Lippold , Hasegawa-Johnson Mark
Published: October 2013

Several courses combine to form an unofficial but nevertheless effective undergraduate and early graduate music technology program at the University of Illinois at Urbana–Champaign. Musical Acoustics is taught within the School of Music and includes topics such as resonance behavior of strings and pipes; perception of loudness, pitch, and timbre; and acoustics of musical instruments. Several courses involving computers and music are taught in the School of Music. These courses discuss the fundamentals of computer music, and extensive computer/recording studios provide students with hands-on opportunities to conduct experiments or to produce audio demonstrations or music compositions. The courses differ in terms of the user interfaces, compositional algorithms, and synthesis models employed. There is also a seminar in analysis and synthesis of sounds. In the Department of Electrical and Computer Engineering, besides conventional digital signal processing, there are several special courses that offer training for a career in music technology. Fundamentals of Engineering Acoustics supplies a rigorous introduction to wave propagation and acoustical systems. Electronic Music Synthesis describes algorithms for music sound synthesis and representation and includes a laboratory component. Topics in Audio Engineering covers psychoacoustics, signal processing, audio coding and recognition, room acoustics, and tranducers.
Radiation-pressure induced frequency shift of liquid capillary bridge transverse modes: A string approximation
Authors: Marston Philip L. , Thiessen David B.
Published: October 2013

Liquid capillary bridges in air have been stabilized by placing them at the velocity anti-node of an ultrasonic standing wave. This radiation-pressure induced stabilization depends on an acoustic parameter q that is proportional to the square of the ultrasonic pressure amplitude [M. J. Marr-Lyon et al., Phys. Rev. Lett. 86, 2293–2296 (2001)]. An approximation developed here suggests that an independent measure of q could be obtained by measuring the increase in the natural frequency of the lowest transverse bridge mode. That mode is known as the (1,1) mode. Even for an inviscid bridge, the exact (1,1) mode description is complicated. This complication is avoided by showing that the natural frequency for long round bridges is approximately that of a string having an effective tension CT/2 where C is the bridge circumference and T the surface tension. The additional restoring force (associated with the acoustic radiation pressure) for a bridge at a velocity anti-node is modeled as a uniform elastic support. When q is small, the frequency shift is predicted to be proportional to q. The calculation should also apply to the use of vibrating strings to measure acoustic standing wave amplitudes. [Work supported by NASA.]
Predicting variability in SEA
Authors: Lyon Richard H.
Published: October 2013

The variability that exists between an SEA estimate of the response of an ‘‘average’’ system and the actual response of a particular system has been estimated in various papers and books by the author. This estimate is in the form of a central limit theorem in which the variance, normalized by the square of the mean, is reduced by a factor that is the number of independent interacting mode pairs. A review of that result indicates that this parameter is overestimated, resulting in an underestimate of the actual variance. A new estimate of the variance is derived, which appears to have the correct asymptotic behavior under conditions of both low and high modal overlap. [Research supported by Cambridge Collaborative, Inc.]
Experimental statistical energy analysis in the time domain
Authors: Gregory Joseph , Keltie Richard , Hall Hubert
Published: October 2013

A technique for identifying an experimentally based power flow model from transient measurements is described. The technique was validated using a range of test simulations and then with true physical tests conducted on a structure comprised of coupled thin plates. The identified power flow model was used to successfully update and improve an existing computational statistical energy analysis (SEA) model. It was found that utilization of time domain data allowed for an overdetermined power balance providing favorable numerical conditions for the identification. Useful insight into system order/dimension was obtained during the identification process. It was observed that a full matrix of measured inputs and outputs was not required. However, inclusion of the extra measurements was seen to further increase overdetermination, yielding an even better least squares estimate of model parameters. It was found that the identification procedure indicated true parameters that were easily distinguished from those associated with noise in the data and, hence, seemed well suited for this SEA application. Results indicate that the methodology has the potential to enhance standard experimental SEA procedures.
Experimental evaluation of coupling loss factors of thin plates
Authors: Panuszka Ryszard , Wiciak Jerzy , Iwaniec Marek
Published: October 2013

Using statistical energy analysis method to gain knowledge of coupling loss factors (CLFs) of structural elements of complex mechanical systems is fundamental, therefore the evaluation of CLFs for different constructional connections of thin rectangular plates merits studying. CLFs for different constructional perpendicular connections of thin rectangular plates were investigated. Three types of couplings were studied: line junction, stiff bridges, and point connections. Investigations were realized with method of energy stored at anechoic chamber. Experimental test included two kinds of connections of tested perpendicular plates: welded line junctions and point junctions. Several combinations of thickness ratio on CLFs values were tested for welded plates. Also, the distribution points were studied to show the impact on CLFs. There is evidence of decreasing of CLFs for larger ratios of thickness especially for higher frequency bands. Acoustic power flow across riveted junctions shows up to 20 dB lower transmission than similar spot welded junctions. In the examined screwed junctions demonstrate lower than average CLFs activity than riveted and higher than point welded.
Applications of time reversal in ocean acoustics
Authors: Kuperman W. A. , Hodgkiss W. S. , Song Hee Chun , Akal Tuncay
Published: October 2013

Electromagnetic, early ocean acoustic experimental and theoretical work as well as laboratory ultrasonics [Zeldovich et al., Principles of Phase Conjugation (Springer-Verlag, Berlin, 1985); A. Parvelescu and C. S. Clay, Radio Electron. Eng. 29, 223–228 (1965); D. R. Jackson and D. R. Dowling, J. Acoust. Soc. Am. 89, 171–181 (1991); M. Fink, Sci. Am. Nov. 91–97 (1999)] suggest that time-reversal (or phase conjugation) methods provide opportunities for an assortment of applications in underwater acoustics. Recently, a series of ocean acoustic experiments have been carried out confirming the robustness and potential utility of time reversal mirrors in underwater acoustics [Kuperman et al., J. Acoust. Soc. Am. 103, 25–40 (1998); Akal et al., 5th ECUA, Lyon, France, 2000]. This total sequence of research is briefly reviewed as an introduction to the research presented in this session. [Work supported by ONR.]
Application of time reversal to reverberation reduction in the ocean
Authors: Kim Seongil
Published: October 2013

Reverberation from rough ocean boundaries causes serious problems in many active sonar applications. Numerous passive signal processing techniques have been developed to effectively extract target signals from reverberation noise. The spatial and temporal focusing capability of the time-reversal method provides a new approach to this problem by actively minimizing the reverberation. A time-reversal process realizes a focus at the probe source position and shadows the boundaries below and above the focus resulting in reduced reverberation. Recent experiments with 3.5-kHz sound showed the possibility of the time-reversal method to the detection problem by demonstrating the enhanced echo-to-reverberation ratio in shallow water. A time-reversal based process for reverberation cancellation from a specified range cell without the use of a probe source has also been developed. An eigen-decomposition of the reverberation data provides the transfer function between the TRM and scatters where the reverberation is generated [Prada et al., J. Acoust. Soc. Am. 99, 2067–2076 (1996); Lingevitch et al., J. Acoust. Soc. Am. 109, 2495 (2001)]. The backpropagated field from TRM with a weight function obtained by projection operations to the null space places an acoustic null at the corresponding boundary. This process results in reduced reverberation returning from the boundary. [Work supported by ONR.]
Passive phase conjugation for underwater communication
Authors: Rouseff Daniel , Fox Warren L. J. , Jackson Darrell R.
Published: October 2013

Active phase conjugation requires an array capable of both transmitting and receiving. A field incident on the array can be refocused both in space and time at the location of the original source. To do acoustic communication, an additional step in the processing is introduced; prior to backpropagation, the measured probe field is first convolved with a data stream. The direction of communication is from the active array to the location of the original point source. By contrast, in passive phase conjugation [D. R. Jackson et al., J. Acoust. Soc. Am. 108, 2607 (2000)] the direction of communication is from the point source to the passive array. Further results from an experiment conducted in Puget Sound are presented. The effects of array curvature and truncation are discussed. [Work supported by ONR.]
Imaging in random media
Authors: Borcea Liliana , Berryman James , Papanicolaou George , Tsogka Chrysoula
Published: October 2013

We present a general method for estimating the location of small scatterers buried in a random, weakly scattering medium, using an active antenna array. The main features of this method are (i) an arrival time analysis of the echo received from the scatterers, (ii) a singular value decomposition of the array response matrix in the frequency domain, and (iii) the construction of an objective function in the time domain that is statistically stable and peaks on the scatterers. By statistically stable we mean that the objective function is self-averaging over different realizations of the medium. This is a new approach to array imaging that is motivated by recent studies of time reversal in a random medium. It combines features from seismic imaging like arrival time analysis with frequency domain radar signal subspace methodology like MUSIC (MUltiple SIgnal Classification).
Impact of depression to elevation internal soliton wave conversion on upslope acoustic propagation—A simulation
Authors: Orr Marshall H. , Mignerey Peter C.
Published: October 2013

Depression to elevation soliton wave conversion has been observed at the South China Sea shelf break during the recent AsiaEX experiment. Numerical simulation of the internal soliton conversion process for a two-layer fluid has been used to generate a range/time-dependent sound speed profile for upslope propagation along a 20-km propagation path. Acoustic signal properties during various stages of soliton conversion are compared. [Work supported by the ONR Ocean Acoustic Program and ONRs NRL base funding.]
Effect of an extra-tropical hurricane on the underwater acoustic environment
Authors: Hutt Daniel , Osler John , Abraham James
Published: October 2013

Hurricanes are a common occurrence along the east coast of North America in late summer and autumn. As a hurricane moves northward, its energy is sustained by circulation of the warm humid air over the Gulf Stream. Hurricanes usually lose energy quickly once they pass north of the Gulf Stream where they are affected by cooler surface water temperatures and mid-latitude winds. However, in some cases hurricanes may reintensify when the frontal zone encounters a strong upper-level trough. Hurricane Michael was one such extra-tropical hurricane that reintensified during passage along the Scotian Shelf in October 2000. Oceanographic conditions on the Scotian Shelf were monitored before, during, and after passage of the hurricane. Bathythermograph surveys and satellite imagery indicate that passage of the hurricane cooled surface waters and increased the thickness of the mixed layer. The effect of the hurricane on underwater acoustic propagation was investigated by calculating broadband transmission loss using a normal modes model in the 20-Hz to 10-kHz band. A comparison of acoustic transmission based on sound speed profiles from before and after Hurricane Michael and from climatology will be presented.
Florida red tides and hearing
Authors: Lu Zhongmin , Xu Zemin
Published: October 2013

Red tides, characterized by patches of colored seawater, have been reported worldwide. They are formed due to blooms of marine phytoplankton populations. Particularly, the dinoflagellate (Ptychodiscus-brevis) has been identified to cause the red tides occurring along the coastline of west Florida. It is known that P.brevis produces many types of neurotoxins, which result in massive kills of fishes, birds, and marine mammals including endangered species. Although some studies demonstrated effects of the neurotoxins on the respiratory system, heart, and neuromuscular junction, no study has ever been reported regarding possible effects of any red tide toxins on sensory systems. This study was to investigate whether or not a neurotoxin purified from Florida red tides, brevetoxin-3, affects hearing in fish. The neurotoxin was intraperitoneally injected into the goldfish (Carassiusauratus), and hearing thresholds were measured using auditory brainstem recording techniques. Results show that the toxin causes significant hearing loss in the goldfish. Species differences in neurotoxin tolerance and mechanisms of the hearing loss are discussed. Results from this study enhance our awareness of neurotoxin effects on sensory systems in vertebrates including humans. [Work supported by NIH Grant No. R29DC03275, UM start-up funds, and NIEHS pilot project award.]