bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the value of staining hair samples with a modified Wright–Giemsa stain and/or showing illustrated guidelines for the microscopic diagnosis of dermatophytosis in cats
Authors: Căpitan Rareş , Schievano Carlo , Noli Chiara
Published: April 2018

Background

Direct examination of the hair is a simple diagnostic test for the diagnosis of dermatophytosis; training is needed to use this test.

Hypothesis/Objectives

To evaluate whether use of modified Wright–Giemsa blue stain and/or photographic images of infected and uninfected hairs improved the user's ability to identify infected or uninfected hairs.

Animals

Ten cats with, and 10 cats without, dermatophytosis due to Microsporum canis (n = 20).

Materials and methods

Twenty unstained and 20 stained hair samples from each group (n = 40) were anonymized and examined by veterinarians using a light microscope. Participants recorded samples as “infected” or “uninfected”. Participants were then shown and allowed to use photographic images while examining the same 40 samples.

Results

Without staining, investigators correctly identified 12.7 ± 4 of the 20 samples (mean ± SD) and with staining 13.6 (±3). After illustrative guidelines were shown, they correctly identified a mean of 16.9 (±2.5) unstained slides and 15.8 (±2.3) stained slides. “Illustrated guidelines” and “hair infection” significantly increased the probability of a correct answer, whereas “staining” did not. Logistic regression determined that “study participant”, “illustrated guidelines” (OR = 2.6) and “hair infection” (OR = 2.1) had a significant influence on the results, whereas “staining” did not. Sensitivity and specificity of direct examination were 70.5% and 56%, respectively, compared with culture status.

Conclusions and clinical importance

When examining hairs for the presence or absence of infected dermatophyte hairs, diagnostic accuracy was improved when observers used illustrated guides compared with just examining stained slides.
Positive Effects of Proprioceptive Neuromuscular Facilitation Stretching on Sports Performance: A Review
Authors: Kaya Fatih
Published: April 2018

The role of flexibility on athletic performance is going on to be studied both acutely and how it affects the performance in the long-term. It is important to understand the effects of various stretching types and define the most appropriate form in order to maximize the human movement and performance. Proprioceptive neuromuscular facilitation (PNF) stretching techniques are commonly used at athletic and clinic settings with the aim of optimizing motor performance and rehabilitation in order to increase range of motion. Yet, new research results put forth that the relation between performance and stretching is not as its thought and come up to this belief with suspicion. The aim of this review is to focus on the positive effects of PNF stretching on performance and to provide the reader with the latest researches on athletic performance. The researches reveal that PNF stretching can increase athletic performance in the long-term. Besides, it is more possible to obtain and maintain the benefits of PNF techniques if they are performed accurately and consistently.
Effect of Sports Satisfaction on Aggression and Stress in Judokas and Swimmers
Authors: Keskin Özlem
Published: April 2018

Entirely 60 athletes (39 judokas and 21 swimmers) participated in this study that was performed in 2 different branches (contact and contactless). The purpose of this paper was to determine the effect of sports satisfaction on aggression level and stress. Three different scales as the stress scale, aggression scale, and sports satisfaction scale were used to collect the data. T-test, one way ANOVA test, regression and correlation tests were used in independent groups to analyze the data obtained from these scales. SPSS 24.00 packaged software analyzed the data. It is seen when an evaluation based on the branches are actualized that point averages of sports satisfaction of both the judokas and swimmers are at a good level. While there is no significant difference in terms of the branch, gender, and education, there are significant differences (p<0,01) in terms of the age group variable at the same time. With reference to our other finding, there is a negative relationship between the sports satisfaction and stress (r=-,320, p<0.01). As the sports satisfaction increases, stress level decreases at the same time. There is seen a negative significant relationship between the age group and aggression levels (r=-,374, p<0,01). As the age decreases, the aggression level increases.
Quality of Life in Obstructive Sleep Apnea-hypopnea Syndrome
Authors: Castellanos Caro Gina Lizeth
Published: April 2018

Obstructive Sleep Apnea/hypopnea Syndrome (OSAHS) has as its fundamental mechanism the failure of tonic dilatation of the pharyngeal muscles during sleep. Its prevalence has been fixed between 2-4% in women and 4-8 % in men. This pathology elevates blood pressure, increases the risk of cardiovascular and cerebrovascular disease, causes excessive drowsiness and decreases the quality of life of patients who suffer it. Approximately 5% of the general population is affected in their daily lives due to this disorder. Therefore, it is pertinent to have instruments that effectively measure every aspect involved in OSAHS. In Colombia, there is currently no validated scale that evaluates the quality of life in OSAHS; however, worldwide, there are several instruments useful in this topic; one of these is the Sleep Apnea Quality of Life Index (SAQLI), which is validated in four languages, including Spanish, but has not yet been validated in our country, which probably involves a language and cultural barrier at the time of application.
Revisión sistemática sobre factores de riesgo asociados a artralgia persistente en el paciente con fiebre del chikunguña
Authors: Caicedo Ochoa Edgar Yaset , Urrutia Gómez Jorge Andres , Niño Fernández Daniel Sebastian , Mendez Fandiño Yardany Rafael
Published: April 2018

Antecedente: La fiebre del chikunguña es una enfermedad tropical infecciosa, caracterizada por la aparición de fiebre, erupción cutánea y artralgias, cuya incidencia ha aumentado en los últimos años, en Asia y Latinoamérica. Aunque es una enfermedad con baja mortalidad, se ha relacionado con limitación funcional a largo plazo, por su compromiso articular. Objetivo: Llevar a cabo una revisión sistemática de la literatura sobre los factores de riesgo asociados a artralgia persistente en el paciente con fiebre de chikunguña. Metodología: Se buscó información en bases de datos como PubMed, Embase, ScienceDirect, Scopus y Google Académico, con el descriptor de búsqueda (chikungunya fever OR chikungunya) AND (arthralgia). Resultados: Se obtuvieron 4281 estudios de los cuales al final se seleccionaron seis estudios de cohorte por su similitud metodológica en la evaluación de factores asociados y de los que se obtuvieron diferentes resultados en el análisis de datos. Conclusión: No existe información concluyente acerca de factores modificables que permitan predecir la persistencia de artralgias en pacientes infectados por el virus de la fiebre del chikunguña. Hacen falta estudios que permitan evaluar la presencia de dichos factores, fin de disminuir la morbilidad asociada a la artralgia persistente.
Malaria mixta: a propósito del diagnóstico de un caso en zona no endémica
Authors: Barahona Correa Julian Esteban , Jiménez Vigna Andrés Mauricio , De Castro Hernández Melissa , López García Juan Carlos
Published: April 2018

Las infecciones por malaria mixta (MMx) son frecuentemente subdiagnosticadas, a pesar de su alta morbimortalidad. La presencia de más de una especie de Plasmodium spp. y su asociación con síntomas palúdicos configura una MMx. El artículo presenta el caso de una paciente pediátrica diagnosticada con MMx en un hospital en una zona no endémica. Se hace una breve revisión del tema y su abordaje terapéutico para Colombia.
Frecuency of Do-Not-Resuscitate Orders in a Level 4 University Hospital
Authors: Gempeler Rueda Fritz Eduardo , Sanín Hoyos Alejandra , Echeverri Lombana María De La Paz , Baloco Barrios Angela Lucia , Parra Pérez Ana María
Published: April 2018

After the introduction of the cardiopulmonary resuscitation into clinical practice, non-resuscitation orders emerged as an alternative for those patients that, for several reasons, were not candidates to receive this type of medical treatment. Over time, the non-resuscitation orders have increased in number, possibly due to the aging of the population, an increase in the prevalence of oncological pathologies or greater awareness of the physicians regarding the outcomes of the patients being carried to a CPR. According to the above, this study was developed with the objective of knowing and describing the frequency of DNR and CPR in patients who died in a level 4 hospital in the city of Bogotá. Likewise, the demographic characteristics of these patients were described.
Boundary layer noise subtraction in hydrodynamic tunnel using robust principal component analysis
Authors: Amailland Sylvain , Thomas Jean-Hugh , Pézerat Charles , Boucheron Romuald
Published: April 2018

The acoustic study of propellers in a hydrodynamic tunnel is of paramount importance during the design process, but can involve significant difficulties due to the boundary layer noise (BLN). Indeed, advanced denoising methods are needed to recover the acoustic signal in case of poor signal-to-noise ratio. The technique proposed in this paper is based on the decomposition of the wall-pressure cross-spectral matrix (CSM) by taking advantage of both the low-rank property of the acoustic CSM and the sparse property of the BLN CSM. Thus, the algorithm belongs to the class of robust principal component analysis (RPCA), which derives from the widely used principal component analysis. If the BLN is spatially decorrelated, the proposed RPCA algorithm can blindly recover the acoustical signals even for negative signal-to-noise ratio. Unfortunately, in a realistic case, acoustic signals recorded in a hydrodynamic tunnel show that the noise may be partially correlated. A prewhitening strategy is then considered in order to take into account the spatially coherent background noise. Numerical simulations and experimental results show an improvement in terms of BLN reduction in the large hydrodynamic tunnel. The effectiveness of the denoising method is also investigated in the context of acoustic source localization.
Investigating the stability of frequency-dependent locally reacting surface boundary conditions in numerical acoustic models
Authors: Oxnard Stephen
Published: April 2018

Numerical acoustic modeling enables simulation of sound propagation through bounded space. Recent research directed to refining Finite Difference Time Domain solutions for acoustic prediction has focused on emulating sound wave-surface interaction. Locally reacting surface properties are a popular choice for deriving boundary conditions that incorporate surface absorption properties. However, implementation of these boundary conditions, using the methods described in prevalent literature, is demonstrated here as unstable for complex room geometries. This work presents a reformulated implementation of frequency-dependent locally reacting surface boundary conditions for Finite Difference Time Domain simulations that is empirically demonstrated to be robust against simulation instabilities.
Level dominance effect and selective attention in a dichotic sample discrimination task
Authors: Tan Alison Y. , Berg Bruce G.
Published: April 2018

Differences in individual listening patterns are reported for a dichotic sample discrimination task. Seven tones were drawn from normal distributions with means of 1000 or 1100 Hz on each trial. Even-numbered tones (2, 4, and 6) and odd-numbered tones (1, 3, 5, and 7) were drawn, respectively, from distributions with a 50-Hz and 200-Hz standard deviation. Task difficulty was manipulated by presenting odd and even tones at different intensities. In easy conditions, high and low informative tones were presented at 70 dB and 50 dB, respectively. In difficult conditions, high informative and low informative tones were presented at 50 dB and 70 dB, respectively. Participants judged whether the sample was from high- or low-mean distribution. Decision weights, efficiency, and sensitivity showed a range of abilities to attend to high informative tones, with d′ from 2.4–0.7. Most listeners showed a left-ear advantage, while no listeners showed a right ear advantage. Some listeners, but not all, showed no loudness dominance effect with the ability to selectively attend to quiet tones in difficult conditions. These findings show that the influence of an attentional strategy in dichotic listening can overcome the loudness dominance effect for some listeners.
Three-dimensional modeling in the Weymouth Fore River
Authors: Porter Michael B. , Duda Timothy F. , Traykovski Peter , Newhall Arthur , Henderson Laurel
Published: April 2018

The Weymouth Fore River in Eastern Massachusetts is an estuary that presents an interesting example of a constrained environment. The river bank, of course, channels the energy. Man-made features such as the Fore River Bridge, several piers, and the USS Salem (a heavy cruiser) also present interesting features in terms of the sound propagation. We are using this site as the first of several to validate acoustic modeling tools in such constrained spaces. A detailed bathymetric survey was done providing centimeter level resolution using the Woods Hole Jetyaks. The environmental information is the input to a three-dimensional beam tracing model. This talk will present preliminary comparisons of the measured and modeled acoustic data.
Fractal and bio-inspired labyrinthine acoustic metamaterials
Authors: Krushynska Anastasiia , Bosia Federico , Pugno Nicola M.
Published: April 2018

Control of low-frequency sound is a challenge, despite numerous advances in the field. Recently emerged acoustic metamaterials have already proven their efficiency for the development of innovative systems for sound control and demonstration of such fascinating phenomena as super-resolution imaging, transformation acoustics, acoustic cloaking, etc. For sound attenuation, a common attenuation mechanism relies on dispersion induced by local resonances that results in the generation of slow sound inside a metastructure at resonant frequencies. However, the selective bandwidth of metamaterials with identical resonators restricts their practical applications. To overcome this limitation, one can introduce rainbow-type resonators that leads to the increase of structural sizes and raises manufacturing costs. We present fractal and bio-inspired labyrinthine acoustic metamaterials with non-resonant elements for low-frequency sound control. Designed configurations contain sets of narrow channels extending wave propagation paths that leads to reduction of effective sound speed within a structure. We show that by folding these channels into fractal space-filling curves or bio-inspired geometries, one can induce strong artificial Mie-type resonances that allow the achievement of total broadband sound reflection at deep subwavelength scales. This unique phenomenon can be used to develop small-size metastructures with total reflectance of low-frequency sound for versatile applications.
3D printed sound absorbers using functionally-graded sonic crystals
Authors: Guild Matthew D. , Rothko Michael , Sieck Caleb F. , Rohde Charles , Orris Gregory
Published: April 2018

In this work, a thin functionally-graded sound absorber that achieves an absorption coefficient near unity is demonstrated. The sound absorber consists of a multilayer arrangement of an interwoven sonic crystal lattice with varying filling fractions, backed by a thin elastic coating that acts as a flexural acoustic element. The overall thickness of the sound absorber is about one tenth of the wavelength in air, and it was 3D printed with a thermoplastic polyurethane. Samples were fabricated and acoustically tested in an air-filled acoustic impedance tube, from which absorption and effective acoustic properties were obtained. A theoretical formulation for the effective acoustic properties of the sonic crystal lattice was used to guide the design process, and excellent agreement was found between measured and theoretically predicted results. A range of sonic crystal filling fractions and thicknesses were tested to verify the fabrication process and robustness of the theoretical formulation, and both were found to be in excellent agreement. Based on this testing and analysis, an optimal arrangement was found that achieved simultaneous near zero reflectance and transmittance over a given frequency band, thereby resulting in an absorption coefficient near unity. [Work supported by the Office of Naval Research.]
Modeling acoustic resonators: An application to resonator-enclosure coupling
Authors: Goates Caleb B. , Sommerfeldt Scott D. , Copley David C.
Published: April 2018

Acoustic resonators, such as the Helmholtz resonator, provide a stable, cost effective passive noise control solution, and have been widely used to attenuate unwanted sound in enclosures and ducts. Classical formulations predicting the input impedance of such resonators often have significant error, creating a need for repeated prototyping or tuning during fabrication to achieve the desired response. Previous work found that higher-order calculations, including impedance translation and equivalent circuit modelling, produce much more accurate predictions [Calton and Sommerfeldt, J. Acoust. Soc. Am. 139, 2205 (2016)], allowing prototyping to be done quickly on a computer before fabrication of the resonators. This talk will continue the discussion in the work referenced above. In addition to resonator impedance predictions, resonator-enclosure coupling predictions will be discussed. It will be shown through comparison of predicted and experimental results that the impedance and coupling predictions can remove the need for repeated prototyping and tuning. We will also show the incorporation of these predictions into a user interface allowing engineers without acoustics background the ability to design resonators for passive noise control.
Fibrous material microstructure design for optimal structural damping
Authors: Xue Yutong , Bolton J. S.
Published: April 2018

It is shown here that properly designed fibrous media (e.g., glass or polymeric fibers) can be used to damp structural vibration as well as to absorb sound. The materials can then be multi-functional, reducing the number of elements required to achieve a specified level of noise and vibration performance. Past work demonstrated that layers of fibrous media placed on panels can damp the panel motion by removing energy from the nearfield acoustical motion generated by the panel vibration. The current study focused on designing the fibrous medium to ensure optimal vibration damping in a particular application. First, a method of calculating the response of a panel with an attached fibrous layer is recalled and updated to allow layers of limp or elastic porous media to be modeled. Example results will be presented, and then it will be shown that an optimal flow resistivity exists for a given frequency range and configuration of interest. Finally, based on a recently developed theory for the flow resistivity of fibrous media, the optimal flow resistivity identified in that way can be translated into a particular fiber size, given properties such as density of the fiber material and the desired superficial density.
Vibration isolation of sensory deprivation tanks
Authors: Miller-Klein Erik , Golden Matthew V.
Published: April 2018

Sensory deprivation tanks or float tanks are advertised to be a powerful stress-relief and wellness tool. In these tanks, a person floats in a salt water bath and is enclosed to cut off all visual and auditory sensory inputs. Vibration can have a significant effect on the experience of using a one of these tanks by disrupting the sensory deprivation experience. A recent project will be discussed where vibration was causing such a problem. A solution was developed using recycled rebounded rubber crumb. The subject and object performance data will be shared.
Numerical investigation of coupling schemes for structural acoustics
Authors: Miller Scott T. , Bunting Gregory , Reynolds Nicholas A.
Published: April 2018

Loosely coupled schemes for structural-acoustic coupling are examined that obtain the same order of accuracy as the monolithic scheme. The coupling algorithms are implemented in Sierra-SD, a massively parallel finite element application for structural dynamics and acoustics. By adapting the predictor-corrector scheme of Farhat et al. (2006), second order time accuracy is achieved with the loosely coupled approach. Node-to-face mappings allow arbitrary discretizations of the structural-acoustic interface. Convergence rates are verified with a one dimensional piston problem with known solution. Numerical results are compared to a shock induced plate experimental benchmark. Computational times for loose and strong coupling are compared for a sphere scattering problem. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.
Bimodal neglect: When electrically- and acoustically stimulated ears do not play nice with each other
Authors: Svirsky Mario , Neuman Arlene C.
Published: April 2018

This study describes speech perception in quiet, before and after implantation, in 54 adult cochlear implant (CI) patients with usable hearing in the ear contralateral to the CI. Patients had preoperative aided CNC word scores of at least 8% as well as stable unaided hearing in the unimplanted ear throughout the analysis period. Word identification scores in quiet were analyzed for the implanted ear only (CI), acoustic hearing ear only (HA), and the bimodal condition (CI + HA) to determine changes in performance over time and to characterize bimodal benefit (difference between bimodal score and best single-ear score). On average, patients experienced 6% bimodal benefit in quiet after implantation. Not surprisingly, speech scores in the implanted ear and in the binaural condition significantly improved post-implantation. However, scores in the HA decreased unexpectedly after implantation in almost one third of the patients despite unchanged PTA. Although simple explanations like hearing aid malfunction or improper fitting cannot be entirely ruled out, it is possible that these decreases in speech perception may be due to centrally driven neglect of auditory input from one ear when the contralateral ear becomes dominant due to highly asymmetric input.
Auditory and non-auditory effects of asymmetrical hearing loss in animal models
Authors: Lauer Amanda
Published: April 2018

Animal models offer an opportunity to investigate the consequences of asymmetrical hearing loss with a level of control over extraneous variables that is not possible with human listeners. Experimental manipulations to induce unilateral conductive or sensorineural hearing loss in animal models have demonstrated substantial and diverse changes in physiological function, anatomical reorganization of neural projections, and adverse effects on auditory behaviors. Our experiments in rodents exposed to acoustic trauma with one ear plugged result in asymmetrical hearing loss and abnormal auditory brainstem response waveforms that occur when either the unprotected or protected ear is stimulated. Susceptibility to auditory brainstem response deficits appears to differ between the right and left sides. Asymmetrical hearing loss is associated with increased startle reactivity to loud sounds, suggesting abnormal loudness perception or an increased emotional response to sound. These animals also show abnormal social interaction, and some subjects show reduced exploratory behavior in a novel environment indicative of heightened anxiety. These studies provide a framework for investigating the interplay between the auditory and non-auditory behavioral consequences of hearing loss, as well as the underlying neuropathology.
Talk to my better ear: Consequences of asymmetric bilateral hearing in development
Authors: Gordon Karen A. , Polonenko Melissa , Papsin Blake
Published: April 2018

We study consequences of asymmetric hearing in children with bilateral profound deafness who used a unilateral cochlear implant before bilateral implantation and children who had access to acoustic hearing in one ear with or without a hearing aid before receiving a cochlear implant in the opposite ear (bimodal). Electrophysiological and behavioral measures post-implantation reveal benefits of bilateral implant/bimodal device use but also persistent consequences of early asymmetric auditory input. Auditory cortices maintain an aural preference for the first hearing ear despite chronic bilateral/bimodal hearing. Asymmetries are also evident in speech detection and perception; children receiving bilateral cochlear implants with long delays continue to favour their first implanted ear in both quiet and noise. Children with bimodal devices who have insufficient hearing in the non-implanted ear begin to prefer to listen with the cochlear implant. Impaired binaural hearing in groups with asymmetric function are evidenced by poor integration of input from the two devices and impaired perception and cortical processing of interaural timing differences. Together, these data suggest that children who had a period of asymmetric hearing in early life continue to have aural preference for a “better ear” which could compromise development of binaural/spatial hearing.
The effects of early acoustic hearing on speech perception, language, and literacy abilities of pediatric cochlear implant recipients
Authors: Davidson Lisa S.
Published: April 2018

The primary aim of our current project is to determine the degree to which a period of hearing aid (HA) use facilitates language development in children following the receipt of their first cochlear implant (CI). We tested 117 pediatric CI recipients ranging in age from 5 to 8 years on tests of speech perception and standardized tests of receptive vocabulary and language. Follow up testing (ages 7–10 years) included early literacy assessments. The speech perception test battery includes word recognition in quiet and noise (segmental perception), talker and stress discrimination, and emotion identification (suprasegmental perception). A continuum of residual hearing levels and length of HA use are represented: some children have bimodal devices, while others received their second CI either simultaneously or sequentially at varying time intervals since their first CI (mean age at 1st CI/s = 2.1 years). Comprehensive threshold and device histories were collected on all CI recipients. Based on our analyses, we identified a critical duration of HA use for each of three ranges of hearing loss severity (pure-tone-averages of 72, 92, and 110 dB HL) that maximizes suprasegmental perception (which operates independently from segmental perception to promote spoken language and literacy).The clinical implications of these results will be discussed.
Outdoor acoustic tomography using retrieved Green’s function from controlled-sources: An Experimental Feasibility Study
Authors: Denis Max , Collier Sandra L. , Noble John , Alberts W. C. Kirkpatrick , Ligon David , Sim Leng , Reiff Christian G. , James Deryck D.
Published: April 2018

In this work, outdoor acoustic tomography is investigated using the retrieve Green's function originating from a virtual source located inside a region of interest (ROI). Of particular interest are the location and amplitude of reflectors, as well as the extraction of atmospheric conditions. Existing methods utilize Green’s function retrieval approaches, such as cross-correlation (CC) and multidimensional deconvolution (MDD), of reflection data from inhomogeneities (virtual sources) within the ROI. This allows one to retrieve the Green's function without detailed knowledge of the medium itself. The imaging resolution, artifacts, and close match with the true reflectors are investigated and discussed for both Green’s function retrieval methods.
Evaluating the effectiveness of subarrays in beamforming computations of complex jet noise source environments
Authors: Van Komen David F. , Neilsen Tracianne B. , Harker Blaine M. , Gee Kent L. , Swift S. Hales , Wall Alan T. , Downing Micah , James Michael M.
Published: April 2018

Conventional acoustic beamforming methods, while powerful for localizing acoustic sources, require an uncorrelated monopole assumption, depend on the input array location, and are unreliable in a complex source environment, such as jet engine noise. The complexities arise from the large, partially correlated, extended source region, the multiple types of noise sources, such as directional and omnidirectional, and partially correlated sources that violate the integral uncorrelated monopole assumption of beamforming. The complexity of these sources requires advanced beamforming methods. The aim of this research is to determine what advanced beamforming methods tell us about complex, full-scale jet noise sources. To learn about these sources, an array spanning the entire length of a jet from an F-35 aircraft is split into multiple subarrays. Application of the beamforming algorithm to a subarray in the maximum sound region localizes the directional sources present in jet noise; a subarray to the side of the engine characterizes more omnidirectional sources; and a subarray farther forward yields the approximate origin of broadband shock-associated noise. Using these advanced beamforming methods, combined with the subarray processing, opens new insights in this complex environment. [Work supported by the Air Force Research Laboratory; data courtesy of F-35 JPO.]
Old problems, new solutions: Architectural acoustics in flux
Authors: Sauro Ronald
Published: April 2018

Many problems that have plagued architectural acoustics for years and have escaped real solutions because of a lack of research and measuring facilities. We will explore the types of problems that are still around and the facilities that are needed to explore those problems. This will include reverberation rooms that have the abilities to explore VLF problems in absorption and transmission loss as well as sound power problems at these irritating very low frequencies. This exploration will include looking at present day abilities including specifications of the future rooms that are needed. Extended frequency response information is needed in today's litigious society when everything offends someone else and helps consultants provide solutions to present and future problems.
Biosonar beampattern measurements in flying old world leaf-nosed bats
Authors: Zhao Yanan , Ma Hui , Müller Rolf
Published: April 2018

Emission beampatterns, i.e., emitted ultrasound amplitude as a function of direction and frequency, could be an important characteristic of a bat's biosonar since they determine which part of an environment is illuminated with a given frequency and at a given time. Numerical results have predicted intricate geometrical features such as multiple peaks and notches in bat biosonar beampatterns. Furthermore, it has been shown that bats with nasal emission change the shapes of their emission baffles, “noseleaves,” during pulse emission. The work presented here is aimed at understanding if and how these two aspects (beam geometry and emission dynamics) are integrated into the bats' biosonar behaviors on the wing. The experiments are conducted with Old World leaf-nosed bats (Hipposideros pratti and Hipposideros armiger) that have a pronounced noseleaf dynamics. The animals fly in a tunnel that is instrumented with synchronized arrays of high-speed video cameras and microphones. The setup allows for precise tracking of the bats with high spatial resolution as well as beampattern estimates as a function of time. A first pilot dataset has indicated the presence of local shape features in the beampattern that can also vary with time. However, further testing is needed to corroborate these findings.
Characterization of pinna motion patterns in hipposiderid bats
Authors: Qiu Peiwen , Müller Rolf
Published: April 2018

Hipposiderid bats have a set of highly differentiated pinna muscles that support different pinna motion patterns during biosonar behaviors. It has been shown that these bats' pinna motions fall into two separate categories: Rigid motions that change only pinna orientation and non-rigid motions that also change pinna shape. It remains unclear if further subdivisions of these two categories (e.g., different orientations for rigid motions and different deformation patterns for non-rigid motions) can be made. In order to investigate this question, experiments have been conducted where the positions of a dense set of landmark points (50–80 per pinna) were reconstructed based on footage from an array of four high-speed video cameras. The resulting point trajectory data (positions as a function of time) was clustered to facilitate the detection of patterns. Clustering revealed a structure of coherent surface patches for rigid as well as non-rigid motion. For the rigid motion pilot data set, these patches followed a constant pattern that reflects different motion directions. Within the non-rigid motion pilot data, there were similarities as well as pronounced differences among the analyzed motion sequences, which leads us to formulate the hypothesis that there could be more than one type of non-rigid pinna motion.
System integration for a biomimetic dynamic sonar head
Authors: Conte Dean , Mun Lucas , Dawda Shubham , Walker Brandon , Sutlive Joseph , Müller Rolf
Published: April 2018

Horseshoe bats (Rhinolophidae) have dynamic biosonar systems with interfaces for ultrasonic emission/reception that deform while diffracting the outgoing/incoming sound waves. This peripheral dynamics has been shown to enhance sensory information encoding. To investigate the properties and potential uses of these system features in the real world, a biomimetic sonar head is being developed with the goal of mimicking as much of the bats' peripheral dynamics as faithfully as possible. Further constraints on this development were suitability for integration with mobile platforms and support for interactive quantitative/in-depth experimentation. Flexible noseleaf and pinna shapes along with an actuation system have been designed to mimic the static geometry of the respective structures in bats as well as several of the animals' degrees of freedom in deforming them. The electrical subsystem has been designed to support high-quality ultrasound generation and recording. Generation of all source voltages and signal amplification have been consolidated into a single circuit board to reduce weight and complexity of the overall system. The frame has been altered to reduce weight and add modularity to the noseleaf and pinna elements. The software architecture is based on a back-end (Python, LabVIEW) combined with a flexible front-end (MATLAB) for experimental design and data analysis.
Progress on the use of autonomous underwater vehicles to study estuaries
Authors: McNeil Craig L. , Shcherbina Andrey , Isakson Marcia J. , Kidwell Autumn N. , Reeder D. Benjamin , Lavery Andone C. , Geyer W Rockwell
Published: April 2018

Estuaries are a challenging environment to use acoustically navigated Autonomous Underwater Vehicles (AUVs) due to highly variable currents, relatively shallow and variable bathymetry, large buoyancy changes, suspended sediments, marine biota, and bubble plumes. The benefit to using AUVs is their ability to perform repeat automated surveys and targeted sampling of features using either remote control or on-board redirects. Our REMUS 100 AUVs are equipped with up/down looking ADCPs, CTDs, and optical backscatter sensors. Our AUVs use Long Base Line (LBL) underwater navigation, with up to four transponders, and were recently equipped to carry broadband hydrophones. We will share our experience operating these AUVs in several estuaries to characterize variability in optical and acoustical backscatter associated with estuarine features of interest (fronts, river plume, and the salt-wedge). We will discuss how these features negatively impact AUV sampling via, for example, degraded underwater communications and bottom tracking. We will also present some examples of concurrent sampling by AUVs and an advanced sonar (static and mobile) demonstrating the potential use of AUVs in estuarine research for 4D visualization of estuarine features of interest. [This work was supported by Office of Naval Research.]
Effects of tidal forcing in an estuarine environment on high-frequency acoustics
Authors: Isakson Marcia J. , Kidwell Autumn N. , Story Mark
Published: April 2018

Tidal forcing in rivers and estuaries has a large impact on the use high-frequency acoustics for bathymetric mapping. Changes in the sound speed profile due to changing salinity and temperature conditions affect acoustic propagation, and bubbles, entrained in the tidal flow, cause high backscattering and attenuation. In this study, a forward-looking, high-frequency bathymetric sonar was used to observe estuarine dynamics near the mouth of the Connecticut River in June 2017. The sonar was deployed on a REMUS 600 AUV under the fresh water plume near the river mouth during flood tide, in the lower estuary during ebb tide and in the upper estuary during slack tide. Backscattering from subducted bubbles was observed which was dependent on the propagation path through the fresh or salt water. The bubble backscatter over a 200-m swath at the front of the fresh water plume allowed the structure of the plume to be observed from beneath the surface. These data are compared with other measurements on site, including X-Band radar and in situ salinity and temperature measurements. The data can be used to understand both acoustic propagation and estuarine dynamics in constrained environments. [Work sponsored by the Office of Naval Research.]
Acoustic propagation in the Connecticut River at low-to-mid frequencies
Authors: Reeder D. Benjamin , Joseph John E. , Rago Tarry
Published: April 2018

An estuary is a constrained environment which often hosts a salt wedge, the stratification of which is a function of the tide's range and speed of advance, river discharge volumetric flow rate and river mouth morphology. A field experiment was carried out in the Connecticut River in June 2017, one goal of which was to investigate the low-to-mid-frequency acoustic propagation characteristics of the riverine salt wedge as well as the plume outside the river mouth. Linear frequency-modulated (LFM) acoustic signals in the 500–2000 Hz band were collected during several tidal cycles. Data-model comparisons demonstrate the degree to which this highly energetic environment impacts acoustic propagation; dominant mechanisms are sound speed stratification, boundary interaction, flow noise, and background noise.
Real-time monitoring of transcranial focused ultrasound in vivo
Authors: Liu Dalong , Ebbini Emad S.
Published: April 2018

Transcranial focused ultrasound (tFUS) is being investigated in a variety of medical applications. Both thermal and mechanical bioeffects of tFUS are of interest, but localization of the tFUS therapeutic beam remains a major concern in the presence of beam distortion through the skull. We have developed a system for monitoring and delivery of tFUS using dual-mode ultrasound array (DMUA) transducers. The system is capable of delivering therapeutic tFUS in pulsed mode with imaging pulses interleaved at frame rates up to 500 fps utilizing the same array elements. In this way, the DMUA provides inherent registration between the imaging and therapy system thus providing feedback from the target region as well as tissue structures in the path of the beam. The beamformed DMUA echo data was used to image the thermal and mechanical tissue response to the tFUS beam with high spatial specificity. In vivo data from small-animal experiments have shown a temperature sensitivity of 0.2°C with high spatial specificity. Speckle tracking at up to 500 fps also allowed for tracking mechanical deformation produced by the tFUS beam in the presence of pulsations and other brain tissue motions. These results demonstrate the feasibility of characterizing both mechanical and thermal effects of subtherapeutic tFUS beams in vivo. The results are significant in burgeoning applications where the neuromodulatory response is induced by a combination of thermal and mechanical interactions.
Transcranial acoustic cavitation localization with ultrafast power cavitation imaging in non-human primates
Authors: Burgess Mark T. , Karakatsani Maria E. , Apostolakis Iason , Konofagou Elisa
Published: April 2018

Acoustic cavitation-guided blood-brain barrier (BBB) opening with focused ultrasound (FUS) and microbubbles is a promising technique for safe and controlled opening of the BBB. Passive cavitation imaging has the ability to monitor the spatial intensity of acoustic cavitation for targeting verification and treatment monitoring. However, isolating acoustic cavitation emissions from tissue and skull reflections is a major challenge. In this study, we perform transcranial passive cavitation imaging with a 1.5D imaging array (M5Sc-D, bandwidth: 1.5–4 MHz, GE Medical Systems) placed in the central opening of a 0.5 MHz FUS transducer (H204, Sonic Concepts) in non-human primates. Broadband FUS pulses were used along with synchronous transmit and receive sequences to perform delay and sum beamforming with absolute time delays. Image sets were acquired at ultrafast frame rates (>1000 frames per second) for calculation of mean intensity images, i.e., power cavitation images. Spatiotemporal clutter filtering of image sets was explored over a range of FUS peak negative pressures (0.05–0.75 MPa) to increase power cavitation image sensitivity. Future work will explore the use of this method for safe and controlled BBB opening based on power cavitation image feedback. [Work supported in part by NIH grants R01AG038961 and R01EB009041.]
Transcranial focused ultrasound with multielement arrays: Decreasing the number of transducers without compromising the focusing quality
Authors: Aubry Jean-Francois
Published: April 2018

Transcranial ultrasonic brain therapy at frequencies higher than 500 kHz requires adaptive focusing to compensate for the aberrations induced by the skull bone. This can be achieved by using multi-element arrays driven by a dedicated electronics. A growing number of elements was used to improve the focusing: 64 elements in 2000 [1], 300 in 2003 [2], 1024 in 2013 [3], and more to come. We will present some of the salient results obtained pre-clinically and clinically with such multi-element transcranial devices. Nevertheless, we will show that comparable transcranial focusing can be achieved with a novel approach in rupture with the current trend. It consists in a single-element transducer covered with a 3D silicone acoustic lens of variable and controlled thickness. Similar lenses have been introduced in the past to perform multiple focusing patterns in homogenous media [4] but recent 3d printing capabilities make 3D lenses a feasible option for transcranial adaptive focusing. We will show that the use of a lenses increases the acoustic intensity by 97 ± 56% on average, on three human skulls. [1] G. Clement et al., “A hemisphere array for non-invasive ultrasound brain therapy and surgery,” Phys. Med. Biol. 2000. [2] M. Pernot et al., “High power transcranial beam steering for ultrasonic brain therapy,” Phys. Med. Biol. 2003. [3] N. Lipsman et al., “MR-guided focused ultrasound thalamotomy for essential tremor: a proof-of-concept study,” The Lancet Neurology 2013. [4] T. Fjield et al., “Low-profile lenses for ultrasound surgery,” Phys. Med. Biol. 1999.
Architectural acoustics: From concert halls to classrooms
Authors: Freiheit Ronald , Neal Matthew T.
Published: April 2018

Architectural Acoustics (AA) finds its application in and around the built environment and, in doing so, touches and interacts with many different disciplines. Within ASA, the TCAA consistently hosts joint special sessions with the noise, musical acoustics, psychological and physiological acoustics, and signal processing technical committees. Apart from its involvement with special sessions, many unique subcommittees bring added diversity within architectural acoustics. These include subcommittees on classroom acoustics, speech privacy, green building acoustics, healthcare acoustics, building performance standards, and the concert hall research group (CHRG). The makeup of members in the AA group is quite varied. It includes those involved in education and research to those in consulting as well as those in industries that supply products to this segment. Along with published research which is typical of most technical committees, a large segment of the TCAA’s accomplishments are based on the projects produced by consultants or the products provided by industries. The AA group has consistently been one of the larger groups of active participants. There is a unique balance between research, application, and industry support for this segment of acoustics, making the TCAA a great place to see new perspectives and make new connections with colleagues, friends, and mentors.
Tools for assessing efficacy of hearing loss compensation
Authors: Vastare Krishna Chaithanya , Luna Sergio , Zubaity Tamara , Chockalingam Ganz , Garudadri Harinath
Published: April 2018

We are developing a real-time, wearable, Open-source Speech-Processing platform (OSP) that can be configured by audiologists and Hearing Aid (HA) researchers for lab and field studies. This contribution describes OSP tools to (i) control the HA state, such as amplification parameters in each subband, (ii) provide stimuli to the user, and (iii) get feedback from the user. The system is based on a web server with interfaces to the HA state, the environment state (e.g., background noise characteristics, reverberation conditions, GPS location, etc.) and the user state (as inferred from ecological momentary assessments). We describe Application Programmer’s Interfaces (APIs) used in Hypertext Markup Language (HTML) and server side scripting language (e.g., PHP) to create web applications aimed at assessing efficacy of various Hearing Loss (HL) compensation approaches. HTML and PHP are versatile tools and lot easier to develop functional skills compared with software tools used in the OSP. We provide example scripts to run tests such as A/B comparison, American version of the four alternative auditory feature test (AFAAF), etc. Audiologists and hearing scientists can modify these example scripts to create studies aimed at understanding the interactions between HA state, environment and user state and discover novel HL compensation approaches.