bluuebunny/crossref_metadata_2025 huggingface dataset:
The adaptation of the façade sound insulation requirements in the Belgian standard
Authors: Ingelaere Bart , De Geetere Lieven , Vermeir Gerrit , Vandamme Manuel
Published: May 2008

In a previous paper, a draft of the new Belgian requirements for the sound insulation in dwellings in the prNBN S01-400-1 was presented. During the public enquiry, there was protest of the architectural associations against the façade sound requirements and this part of the draft had to be revised. Architects complained that it would become almost impossible to build even smaller projects without the help of acoustical engineers, what would increase building costs. The building market for dwellings is mainly a liberal market of an individual architect working for a single family, and only the intervention of a structural engineer is usual. The façade requirements are expressed as a function of the outdoor noise and concern the finished building. Architects found the relation of these requirements with the performance of the façade elements as can be calculated by EN 12 354-3:2000 too complicated. A simplified approach was developed and got the approval of the building sector and will be detailed in the presentation. Due to federal law on "the obligatory use of good craftsmanship in building", requirements in standards in Belgium are obligatory. The new standard will be of application from the 15th of February 2008.
Latinoamerican perspective of acoustical standards - the Chilean approach
Authors: Roy Kenneth P. , Campos Micaelina
Published: May 2008

A review will be made of current acoustical standards in several countries of Latinoamérica: Brasil, Mexico, Costa Rica, Argentina, Chile, and Perú. Federal standards will be discussed relative to typical end user approaches to meeting requirements. Additionally, press articles warning of health concerns related to acoustics will be presented. Most Latinoamerican acoustical standards include measurements of exterior noise, but do not mention interior noise requirements as mandatory. Brazilian standards establish overall maximum noise levels for different areas, but do not mention acoustical testing of materials. However, this is changing as a multi-professional team in Mexico is working to definition the acoustical coefficients required for ceilings and walls. And, this team is also working to establish levels of acoustical comfort in different office spaces. Most countries in Latinoamerica have federal institutions that deliver technical standards for the building industry. In Chile, we have the "Instituto Nacional de Normalizacion"(National Standards Institute), and they base their standards on the ISO standards. In 2006 they have delivered many acoustical standards and regulations, including those on transmission loss for private housing including social housing parameters. They are planning to work on standards for Healthcare and School segments.
A special procedure to guarantee sound isolation in dwellings
Authors: Beentjes Wilhelmus
Published: May 2008

Brochures of projects for newly build dwellings and apartments create many expectations about the various qualities of the new buildings. This also concerns the quality of the sound isolation. But what happens if the quality is not as one expected and one cannot come to an agreement with the contractor? Where can one get one's rights. In the Netherlands we therefore have the Guarantee Institute Housing ( In Dutch GIW). This organisation guarantees that the building fulfills the requirements of the Dutch Building Decree. In this paper the procedure will be explained in a few cases . The topics can vary from airborne- and impact sound insulation between buildings, the sound insulation of facades to the sound levels produced by domestic installations. What are the possibilities to improve the sound isolation if the measured values do not fulfill the guaranteed values?
The Ellie Caulkins Opera House: A study in simplified predictive modeling
Authors: Mahoney Robert
Published: May 2008

Recent advances in predictive modeling and experience in understanding and interpreting the significance of the data provided by such models have given rise to a spate of wonderful new performance spaces. However the models - whether computer models or physical scale models - demand an investment in time, money and organizational resources that are not always available due to the funding and political climate surrounding some projects. In order to secure public funding for the Ellie Caulkins Opera House in Denver, CO USA, the architectural design team had to combine elements of modeling from both the recent past and decades ago in order to present to public authorities a definitive and detailed design and an equally firm estimate of construction costs quickly and with little investment. This paper discusses how the predictive techniques of the last half-century were synthesized to provide a confident estimate of the proposed design's acoustical character as well as definitive construction information.
A systematic review on the influence of noise on patients' sleep in the Intensive Care Units
Authors: Xie Hui , Kang Jian
Published: May 2008

Noise level in the Intensive Care Units (ICU) often ranges far above the recommended standards. Patients in the ICUs are usually critically ill, making them more susceptible to the unfavorable environment in the hospital. Several objective and subjective methods have been used for the sleep measurement in previous intensive care studies, which showed that the sleep of ICU patients is remarkably and extraordinarily disrupted. While a number of factors may affect sleep in the ICUs, many earlier studies reported that noise is one of the most common causes for disturbed nocturnal sleep among ICU patients, although some other studies also suggested that noise in the hospital environment is not the most frequent cause of patients' awakenings. Moreover, patients would become accustomed to noise accompanied with their hospital stay. In this paper, a systematic review is given to the influence of noise on patients' sleep in the ICUs, and some strategies to improve the sleep quality are also discussed.
Vibration effects in healthcare facilities
Authors: Nash Anthony
Published: May 2008

In the USA, the principal rating system for "green" buildings is named, "Leadership in Energy and Environmental Design" (LEED). There is now a proposed LEED rating system for healthcare facilities as described in a "pilot draft" document that was released for public comment in November 2007. This document, in turn, cites the 2006 AIA/AHA Draft Interim Sound and Vibration Design Guidelines. These AIA/AHA Guidelines focus on both the human perceptual effects of vibration as well as the control of structure-borne noise. This paper addresses another aspect of vibration in healthcare facilities - the effects of vibration upon sensitive diagnostic equipment installed on floors above grade. Such equipment may include magnetic resonance imagers, surgical microscopes, and computed tomography (CT) scanners, some of which do not have specific vibration limits provided by the manufacturer. The obvious need for attaining low-level building vibration may conflict with other design constraints imposed on modern healthcare facilities as architects and engineers strive for lightweight floor bays having widely-spaced support columns. This paper reviews the generic vibration design criteria found in the AIA/AHA Guidelines and discusses them in light of several case studies.
The influence of the stage layout on the acoustics of the auditorium of the Grand Theatre in Poznan
Authors: Sygulska Anna
Published: May 2008

The paper concerns the influence of the stage layout on the acoustic properties of the auditorium of the Grand Theatre in Poznan. An experimental investigation and a numerical calculation were carried out. During the experimental investigation three cases were analyzed. Firstly, the stage was prepared for a concert (acoustical shell), secondly in had sets for the "Wedding of Figaro", and thirdly it was empty. The reverberation time and the acoustic pressure distribution were analyzed. The research was done by the interrupted noise method and by the true impulsive sources (pistol shots). The modified ray method was used in numerical calculations of acoustic field parameters. It turned out that the light weight structures (materials used in construction of stage sets and acoustical shell) had only decorative function and their influence on the acoustics of the auditorium opera theatre is small. Moreover, the investigation proved that the distribution of the sound pressure level in the auditorium is asymmetrical. It is because of the geometrical asymmetry of the stage (only one side wing). An acoustical correction of the stage was suggested i.e. applying of slided acoustics walls to separate the stage from the background and the side wing.
Resonant cavities and acoustics vases in Italian Opera Houses; the "Teatro Principal" of Valencia and the eighteenth century treatises about theatres
Authors: Barba Sevillano Arturo , Giménez Alicia , Lacatis Radu , Cibrián Rosa
Published: May 2008

This paper describes the research job carried out at Polytechnic University of Valencia -Spain- about resonant cavities placed under the orchestra pits of Italian Opera Houses, and others acoustics mechanisms like this one. The Teatro Principal of Valencia was built following the project developed by the Italian architect Felipe Fontana in 1774 and it opened its doors in 1832. Fifteen years ago, in the last architectonic intervention in this theatre, almost a hundred of acoustic vases were found in one of those resonant cavities. What acoustics role they accomplish? How they "functioned"? This was the starting point to study this kind of artifices, throughout the eighteenth century European treatises about theatres and in our Teatro Principal.
Italian opera house Mantua's Teatro Scientifico acoustical parameters measurements' comparison between Neumann KU 100 and Schoeps KFM 6 binaural recording systems
Authors: Policardi Franco , Shimokura Ryota , Consumi Marco C. , Cocchi Alessandro
Published: May 2008

From the dawning of modern acoustics, researchers tryed to develop useful measurement techniques to describe acoustical field. Sound field measurement improvement's first endeavours implementing microphone capsule miniaturization technology date back to the thirtyes of the past century. Long human perception reproduction path through recording tecnique came to the attempt to position transducers similarly to the human natural hearing system, frequently obtaining as alluring results as difficult comparison among them and reapply. This paper describes processes, first results and comparison between as much as possible identical acoustical measurement sessions in Mantua's Teatro Scientifico opera house using Neumann KU 100 and Schoeps KFM 6 binaural recording systems at the same time.
The Temporal and Spectral characteristics of Gamelan Sunda Music
Authors: Merthayasa I Gde Nyoman , Pratomo Bayu
Published: May 2008

In order to design a dedicated Concert hall for Gamelan Sunda, first of all, it is important to determine the temporal and spectral parameters of Gamelan Sunda Music (Degung Musics). Gamelan Sunda's music compositions are strongly affected by the sound envelope and timbre. The fundamental frequencies of instrument keys also affect the musical scale, notes placings and the communication between the musical ensembles. The acoustical parameters of the anechoic studio recorded sound waves has been analyzed to determine the acoustical parameters. The sound envelopement factors have been compared with the note configuration in the musical composition, in order to analyze the influence of the sound envelopement to the music composition. In addition, the effective duration of the autocorrelation has also been analyzed to determine the preffered reverberation time in the proposed Concert hall for Gamelan Sunda.
The influence of the source directivity on the measurement uncertainty
Authors: Vitale Renzo , Witew Ingo
Published: May 2008

Modelling can play a key role in assessing the measurement uncertainties, as specified in the "Guide to the expression of Uncertainty in Measurements" (GUM). A model is presented that is used to quantify the influence of the source directivity on the measurement uncertainty. On the grounds of image sources and radiosity methods the propagation of sound in rooms is simulated. In this model the characteristics of dodecahedron sound sources are implemented with their statistical properties and characteristics. In Monte Carlo Simulations these two core concepts are combined and the results are compared with measurement results. This comparison allows a quality assessment of the model. In a conclusion the input quantities that affect the measurement uncertainty that is introduced by the source directivity are identified.
Sound Insulation Requirements in Hospitals: Comparisons and case studies
Authors: Secchi Simone , Cellai Gianfranco , Nannipieri Elisa , Raffellini Giorgio
Published: May 2008

Italian and EU regulations for sound insulation of hospitals are very hard to be satisfied. Especially with reference to sound insulation from outside noise, the simultaneous presence of important sound sources (refrigerating units, fans and others) and of sensitive receivers (the patients) imposes high requirements for façade sound insulation. Moreover, the necessity to assure high values of natural lighting in interiors imposes the use of large windows on façades. By using the tabular estimation model defined by annex B of the European Norm 14351 for the calculation of the performance of windows and the model of EN 12354-3 for the performance of façades, it is easy to show that the limiting values defined by the Italian Law can be achieved only with a perfect realisation of the building construction. In the paper the comparison between EU regulations for hospitals is shown. Moreover, different case studies of hospital buildings are analysed either with a theoretical approach or with measures carried out in site.
The echolocating bat controls the direction and distance of its acoustic gaze
Authors: Moss Cynthia , Ghose Kaushik , Surlykke Annemarie
Published: May 2008

Echolocation is an active sensing system that depends upon the dynamic interplay between auditory information processing and adaptive motor control. The echolocating bat produces ultrasonic vocalizations and uses information contained in the returning echoes to build a three-dimensional auditory representation of its surroundings. The timing, bandwidth, and duration of echolocation signals used to probe the environment directly impact the information available to the bat's acoustic imaging system. In turn, the bat's auditory representation of space guides its actions--ear movements, head aim, flight path, and the features of subsequent sonar vocalizations. This talk will summarize the bat's adaptive vocal behavior as it engaged in complex spatial tasks. The bat's 3D flight path was recorded with high-speed stereo IR video; its sonar signals were recorded with a microphone array that permitted reconstruction of the emission pattern. The sonar emission pattern of the big brown bat, Eptesicus fuscus, is directional, but broad enough to collect echo information from objects within a 60-90 deg cone, which would enable simultaneous inspection of objects in the frontal plane. Here, we report that bats encountering a complex environment shifted the direction and distance of their sonar gaze to inspect closely spaced obstacles and targets sequentially.
Object-oriented echo perception and cortical representation in the bat Phyllostomus discolor
Authors: Firzlaff Uwe
Published: May 2008

Echolocating bats can identify three-dimensional objects exclusively through the analysis of acoustic echoes of their ultrasonic emissions. However, objects of the same structure can differ in size and the auditory system must achieve a size-invariant, normalized object representation for reliable object recognition. In this talk both the neural representation in the auditory cortex and the behavioral classification of echoes of complex virtual objects that vary in object size are described. Electrophysiological experiments revealed a population of units in the auditory cortex of the bat Phyllostomus discolor which showed an object-size invariant response (14/109 units, 13%). These units respond preferentially to echoes from objects in which echo duration (encoding object depth) and echo amplitude (encoding object surface area) co-varies in a meaningful manner. The electrophysiological results are corroborated by the results of a phantom-target playback experiment, in which it is shown that P. discolor spontaneously classifies most scaled versions of objects according to trained standards. These results indicate that at the level of the bat's auditory cortex, an object-oriented rather than a stimulus-parameter oriented representation of echoes is achieved. This work was supported by the Volkswagen Foundation (I/79782)
Vocal motor control in horseshoe bats - a bottom-up approach
Authors: Kobayasi Kota , Hage Steffen , Ma Jie , Metzner Walter
Published: May 2008

Most animals constantly adjust the spectrotemporal composition of their vocalizations depending on the information content intended to be conveyed by these signals. Whereas most studies focus on the sensory processing of spectrotemporal features of vocalizations in various vertebrates, it is still widely unknown how vocal motor structures in the brain adjust these call parameters. We used echolocation and acoustic communication behaviors in horseshoe bats to analyze the neurobiological and biomechanical basis for the motor control of their vocalizations. Results from pharmacological studies of the vocal motor nucleus, the nucleus ambiguus, lead us to developed a novel model for call frequency control by vocal motor neurons. Neurophysiological recordings combined with pharmacological manipulations at the single cell level in spontaneously vocalizing bats substantiated this model. Biomechanical properties of the larynx were also found to aid in call frequency control: Altering tracheal air flow in an isolated larynx preparation resulted in two distinct frequency bands that were non-harmonically related and reflected the main frequency components of echolocation pulses and communication signals, respectively. In addition, changes in air pressure revealed transitions from periodic to chaotic that occurred within a single signal cycle, giving rise to spectral features observed in horseshoe bat communication signals.
A model of range discrimination of multiple objects by using the linear period modulation signal
Authors: Matsuo Ikuo
Published: May 2008

Using the echolocation, bats can capture moving objects in 3D space. The big brown bats, Eptesicus fuscus, emit the linear period modulation sound and can identify objects with an accuracy of less than a millimeter. The delay separation of three or more closely spaced objects can be determined through analysis of the echo spectrum. However, delay times cannot be properly correlated with objects using only the echo spectrum because the sequence of delay separations cannot be determined without information on temporal changes in the interference pattern of the echoes. We previously proposed the model to determine delays of multiple objects from the echoes by using the linear frequency modulation sound. In order to extract the temporal changes, Gaussian chirplets with a carrier frequency compatible with bat emission sweep rates were used. In this paper, we examined the effect of the window's shape which was changed to extract the temporal changes dependent on delays of multiple objects by using the linear period modulation sound.
Acoustic detection of beaked whales from autonomous recording buoys
Authors: Arias Antón , Johnson Mark , Aguilar Soto Natacha , Madsen Peter T. , Tyack Peter , Mo/hl Bertel
Published: May 2008

Beaked whales are among the least known cetaceans but may be especially vulnerable to mid-frequency sonars. Effective implementation of passive acoustic monitoring (PAM) of beaked whale vocalizations may help both to study the biology of these elusive species and to mitigate human impacts. Here we report results of a feasibility study of PAM performed off El Hierro (Canary Islands) where there are coastal resident populations of two species of beaked whales. An acoustic recording system, comprising a GPS-equipped buoy with an archival acoustic tag (Dtag) suspended 200m below, was deployed in an area with visual coverage from land. The DTAG recorded broadband acoustic data sampled at 96 kHz along with timing and position information from the GPS. The buoy was deployed on 6 days and clicks were clearly detectable in all recordings. A majority of these were confirmed to be beaked whale clicks by comparison against sounds previously recorded from the same species. Visual sightings were then compared against acoustic detections to develop a methodology for estimating the probability of detection as a function of distance and group size. Results demonstrate the effectiveness of sonobuoy-type PAM systems for beaked whales and the possibility for low-cost tests of acoustic detection models.
Automated real-time detection of cetaceans at the Station ALOHA Cabled Observatory
Authors: Oswald Julie N. , Au Whitlow W. , Duennebier Fred K.
Published: May 2008

Hawaiian waters support a wide variety of cetacean species, however, little is known about their occurrence in offshore waters. A cabled ocean bottom observatory located at Station ALOHA (Station ALOHA Cabled Observatory - ACO) provides a unique opportunity to study the occurrence of cetaceans in real-time and over long time scales at a deep ocean research site located 100 km north of Oahu. A retired electro-optical telecommunications cable provides power and broadband Ethernet communications capability to the ACO, allowing real-time continuous acoustic monitoring. The ACO has been operational since February 2007 and includes a hydrophone with a bandwidth of 0.01Hz to 40kHz. Automated methods for detection and identification of cetacean calls have been developed and data are processed in nearly real-time. Several cetacean species have been detected, including: dolphins and humpback, minke, fin, and sperm whales. The relationship between the occurrence of different species and changes in the environment has been explored using near-monthly shipboard oceanographic observations collected at Station ALOHA. In addition, seasonal trends in the occurrence of minke whales, a species that has been especially difficult to study using visual methods due to their cryptic behavior, have been examined.
Validating passive acoustic monitoring data loggers by visual observations
Authors: Kyhn Line A. , Tougaard Jakob , Amundin Mats , Stenback Joanna , Teilmann Jonas , Wennerberg Daniel
Published: May 2008

The use of passive acoustic monitoring (PAM) is increasingly used as a monitoring tool in e.g environmental impact assessments. However, very few studies have focused on validating PAM data against independent observations which is critical in order to compare data from different studies and areas, and over time. In August 2007 we tested two types of odontocete PAM equipment: version 5 T-PODs (Chelonia, U.K.) and PCL's (Aquatec, Lochborough, UK) by comparing acoustic detections to visual theodolite tracings of wild harbour porpoises. Eight T-PODs with known detection thresholds and four PCLs were mounted in four clusters. Detection thresholds of the T-PODs varied from 117 to 125dB re 1μPapp. Based on visual tracks of 28 porpoises it is shown that detection ranges correlated inversely with detection threshold. However, PAM-detection also strongly depended on the angle between the swim track of porpoises and the line to the data logger. Some porpoises were not detected despite swimming within 20m of the nearest data logger. It was not possible to distinguish between recordings from one and more than one animal on the PAM-recordings, despite that the number of animals was known from the corresponding tracks. All in all, the results showed good correspondence between PAM recordings and visual tracings, as well as among PAM recordings.
Development of a prototype electronic tag for studying the migratory behaviour of marine species
Authors: John Prajas , George Jinto , Hariharan Supriya M. , Pillai Saseendran
Published: May 2008

Archival electronic tags can be used as standalone data loggers for sampling the ocean for gathering the environmental parameters and studying the migratory patterns of marine species, identifying their feeding and spawning grounds, etc. A prototype archival electronic tag for monitoring the ocean parameters like temperature, pressure and light intensity has been developed. A digital temperature sensor is used to sample the temperature from the tag's surroundings, while a micro machined piezoresistive silicon digital pressure sensor, which is capable of measuring absolute pressure levels upto 14 bars, provides the depth information. One of the important parameters to be measured is the geolocation of the species, which is computed from the ambient light intensities recorded by the digital light sensor in the tag. These parameters can be sampled and recorded in the memory at preset time intervals, as set at the time of deployment of the tag. This minuaturised tag provides the temperature data with 13 bit resolution, while the pressure and light intensity values have 15 bit resolutions. When used in fisheries studies, the size of the device has to be miniaturised, so that by way of attaching such devices, the normal behaviour of the species remain unaffected.
Discovery of Sound in the Sea website: Educational and media resources
Authors: Vigness Raposa Kathleen , Scowcroft Gail
Published: May 2008

The scientific community and the public have become increasingly aware of, and concerned about, underwater sound. There is growing interest in learning about sources and uses of underwater sound, and potential effects of sound on the marine environment. Underlying this interest, however, is a need to provide scientific information at a level appropriate for the general public and for educational and media professionals that communicate with the public. The "Discovery of Sound in the Sea" website (http://www.dosits.org) provides scientific content introducing the physical science of underwater sound and how people and animals use sound to accomplish various tasks. In addition, it has recently been expanded to include three major resource sections: (1) Media Resources, (2) Teacher Resources, and (3) Student Resources. The Media Resources include a Facts & Myths quiz, Frequently Asked Questions, and PDF reprints of a tri-fold pamphlet and a 12-page educational brochure highlighting the content of the website. The Teacher and Student Resources include structured tutorials, educational games, and PowerPoint presentations. These resource sections provide easy, efficient access to timely information on the science of underwater sound and the current state of knowledge of the effects of underwater sound on marine mammals and fishes.
An area sensitive to apparent acoustic motion in the auditory cortex of the bat Phyllostomus discolor
Authors: Hoffmann Susanne , Firzlaff Uwe , Schuller Gerd
Published: May 2008

The processing of apparent acoustic motion was investigated in neurons in the auditory cortex of anaesthetized bats (Phyllostomus discolor). Apparent motion in the horizontal plane was generated by presenting pairs of pure tones with different interaural intensity differences (IIDs) and temporal separations, i.e. inter-pulse intervals (IPIs). Thus the spatial extent, motion direction and velocity of motion changed for each stimulus pair. A complete stimulus matrix consisted of 81 IID-combinations in the range between -40 to +40 dB IID and was randomly presented via earphones with ten repetitions for up to five different IPIs (6.25 to 150 ms). Thirty percent (71) of the 236 extracellularly recorded cortical single cells or small neuronal clusters showed facilitatory responses to acoustic motion compared to static stimulation and were classified as motion sensitive. With decreasing IPI, all motion sensitive neurons changed their azimuthal receptive field in size or spatial position. Twenty two percent (15) of them preferred small movements in the frontal area at very short IPIs. Most interestingly, the motion sensitive neurons were almost exclusively (97 %) found in the dorsal area of the caudal part of the auditory cortex indicating that this cortical area is specifically involved in the processing of acoustic motion.
Mid-frequency pelagic imaging multi-beam sonar
Authors: Jones Christopher D.
Published: May 2008

A unique circular array multi-beam sonar is used to investigate volumetric imaging of pelagic marine environments. Imaging of a radial volume of the ocean up to a kilometer in range and at 8-12kHz will be discussed, focusing mainly on the imaging of large aggregations of fish in shallow water. Several imaging geometries are presented including backscatter imaging in a shallow water waveguide used to resolve the two-dimensional horizontal structure of large fish schools, and the autonomous deployment of the sonar in a fixed location to create a time series of images and observations of variability over a 24 hour period. The potential for new imaging geometries will be explored including vertical profiling to create volumetric images of different pelagic zones in the ocean. Operational issues related to specific scientific question, and signal processing issues related to circular arrays will be discussed. Preliminary field data will be presented.
Using multi-angle reflections to enhance ecosystem characterization
Authors: Jaffe Jules S. , Godo Olav R. , Pena Hector , Maurer Ben
Published: May 2008

Improved knowledge about target tilt can be used to improve acoustic estimates of abundance and to gain insights into the behavioural patterns of exploited marine species. This is because tilt angle strongly affects backscatter, especially at high frequencies. In order to estimate tilt, a dual-transducer system for synchronous observation of marine organisms at two angles (0o and 9o) at 38 kHz was tested. Data was characterized via the "angle response"; the area backscatter from one transducer divided by the sum of both. This metric was computed for layers of small planktonic organisms as well as fish. While the angle response is almost negligible for small organisms at night and slightly in favour of the tilted transducer during day, there is a significant angle response from fish in layers. A theoretical model supports the idea that this effect is due swimbladder tilt. Backscatter from 13 schools of horse mackerel was also analyzed. Although no statistically significant difference was observed, the variability indicate that the angle response is highly dynamic and dependent on the actual behaviour of the school at time of observation. Further studies are planned to improve upon data collection as well as the theoretical aspects of interpretation.
Application of multiple angle acoustic scatter to remote fish classification
Authors: Roberts Paul L. , Jaffe Jules S.
Published: May 2008

Observation of broadband acoustic scatter from fish at multiple angles has the potential to offer advantages for remote classification in cases where the species exhibit differences in size and or body shape, and animal orientation is unknown or difficult to estimate. However, the total angular coverage of the observations, available bandwidth, and the inter- and intra-species variability in size can significantly influence classification accuracy. These parameters are investigated using laboratory data collected from ten different fish species using a linear array of receivers and a single transmitter with an effective angular coverage of up to 25 degrees with a 3 degree sampling increment. Results indicate that when the species exhibit significant differences in length, even two observations covering only 10 degrees are sufficient to obtain an 80 percent improvement in classification accuracy over a single observation angle. This holds true for a wide range of animal orientations. As inter-species size similarity increases, and intra-species size variability increases, more observations covering a larger range of angles are required to maintain a similar improvement in classification accuracy.
Potential influence of shells on multibeam backscatter imagery within the Te Matuku Marine Reserve, New Zealand
Authors: Schimel Alexandre C. , Johnson David , Healy Terry , McComb Peter J. , Beamsley Brett , Immenga Dirk
Published: May 2008

Backscatter imagery from a KONGSBERG EM3000 multibeam echosounder (300kHz) has been analyzed to investigate its potential for benthic habitat mapping. A MATLAB code has been developed to process both bathymetry and coregistered echo-strength, which includes a simple correction to remove the typical multibeam echo strength swathe contrast introduced by the backscatter incident-angle dependence. Although the correction algorithm does completely remove the effect, it is sufficient to generate maps of suitable quality for further analysis. The processing code was applied to a dataset from a survey performed on two sites in the Tamaki Strait, New Zealand, in August 2007, including a section of the Te Matuku marine reserve. Within the marine reserve, a 400m2 area displays a strong reflectivity that contrasts with its surroundings while a past ground-truth data collection shows the full area is dominated by mud with only some differences in shell fragments distribution. Hypotheses to explain the origin of this reflectivity contrast are formulated and verified against past sediment and benthic survey results with emphasis on the potential influence of shells on multibeam backscatter. The potential of multibeam surveying for detecting the coverage of shells patches in benthic habitat mapping is discussed.
Acoustic methods for water mass delineation in coastal marine ecosystems
Authors: Proni John , Stamates Jack , Carsey Thomas , Zhang Jia-Zhong , Sinigalliano Chris , Sullivan Kevin
Published: May 2008

Acoustical methods play an important role in the in the study of nutrient sources for coral reef ecosystems in the south Florida coastal ocean. Many nutrients released into the coastal ocean are released in distinct water masses such as inlet discharge plumes, wastewater outfall discharge plumes, and hurricane-induced re-suspensions. Using water column acoustic backscatter profiles, obtained via either ship-borne instrumentation or in-situ instrumentation, multidimensional images of nutrient bearing water masses are derived. Said images are of assistance in the design of chemical and biological sampling efforts. Examples of water mass imaging will be presented as well as the use of such images in the design of water quality sampling programs. Using a combination of acoustic backscatter, Doppler current profilers, nutrient (nitrate, nitrite, silica, phosphate, ammonia) samples and microbiological (fecal, protozoa, viruses) samples, flux estimates of said quantities may be made for inlet discharges. Results will be presented for a south Florida inlet having an average net seaward discharge of approximately 200 million gallons per day. Selected acoustic images of treated waste water effluent plumes will be presented and compared with plume spatial distributions inferred from conservative plume tracer studies.
Acoustic data from platforms of opportunity as fuel for ecosystem models
Authors: Handegard Nils Olav , Godoe Olav Rune , Lehodey Patrick
Published: May 2008

Echo sounders are a widely used tool for observing marine ecosystems. Traditionally, rigid designed surveys are used to integrate biomass to a global estimate, which is coupled to traditional stock assessment models. More recently, the focus has shifted from single species assessment to an ecosystem approach, taking into account ecosystem function and dynamics. As a response, several ecosystem models have been developed. The data requirements for these models are different than for the traditional models, and new sensors and platforms have been developed as a response to this need. However, examples on how to integrate these observations with these new models are scarce. We propose a state-space observation-space approach, and compare the results from a vertically structured eco-system model with observations from an echo sounder positioned at the Mid Atlantic ridge. We argue that this approach is less vulnerable to assumptions in the data analysis process, and discuss adequate observations regimes for these models.
The factors that influence the design of an underwater acoustic modem for Arctic missions
Authors: Smerdon Andrew M.
Published: May 2008

As summer Arctic sea ice cover continues to reduce, there is a growing need to monitor the ice-ocean interface to aid in understanding and quantifying Arctic climate change. As part of the DAMOCLES EU 6th Framework programme, several subsea elements of a new Arctic Ocean observing system will be deployed in the Arctic Ocean during 2008. To ensure that the observing system is effective, it is essential that measured data from the ocean environment be delivered in a timely fashion for assimilation with data sets from the ice surface and atmosphere. As several of the observing platforms are drifting freely in the water below the ice, there is a need to communicate data to the surface using underwater acoustic techniques. We discuss the factors that influence the specification of an acoustic modem to achieve this data transfer. These include development of standards for data transfer and storage processes, standby power considerations, logistics of establishing a communication link, and under-ice acoustics.
Acoustic contributions to marine ecosystem studies
Authors: Orlowski Andrzej J.
Published: May 2008

Since the early 1970s, acoustic data collected in a form of calibrated measurements of integrated echo energy have been applied by the Sea Fishery Institute in Gdynia to observe the relationships among fish distribution and marine environment. Measurements were collected primarily with scientific echo sounders operating at 38kHz, 24h a day, and stored in the form of standardized intervals of sailed distance and depth for comparison with values of selected environmental parameters, measured concurrently. Acoustic, biological, and hydrological data were transferred to the complex data base, enabling spatial correlation and four-dimensional analyses of relationships characterising a wide range of the marine organism behaviour. Selected methods and standards of comparison are described to explain how to improve the recognition of relationships between three-dimensional spatial environmental gradients and fish distribution. Results of several case studies, including the influence of hydrologic and seabed characteristics, illustrate the practical application and validity of the methods. Particular attention is given to indicators of the dependence of local fish biomass density on temperature structure in the sea and diel cycles of fish behaviour. Animations of time-dependent processes, modelled on the collected data, will be included as a new tool for marine ecosystem analysis.
On some possibilities and properties of matched-field geoacoustic inversion in shallow water
Authors: Zharikov Alexander , Kravchun Pavel
Published: May 2008

The aim of this paper is to estimate possibilities of matched-field geoacoustic inversion (MFI) in shallow water, and to recommend optimal arrangements of signal source and hydrophone array in variety of particular environments. We assumed ocean to be range independent with bottom consisting of homogeneous liquid layers. Sound fields were calculated as superposition of normal modes and continuous spectrum for tonal point source and vertical line array. MFI based on Bartlett processor was used. Possibilities of MFI were characterized by MFI penetration depth, sensitivity to various bottom parameters and non-uniqueness of inverted data. These characteristics were analysed as functions of frequency and the source depth and range for different values of sound attenuation in sediments and for various sound-speed profiles. To estimate possibilities of MFI in real ocean conditions, influence of array tilt and inadequacy of geoacoustic model were analysed. The influence of continuous spectrum was also discussed. Among the major results, optimal source ranges corresponding to the maximum penetration depth of MFI were calculated, and high influence of attenuation in sediments on possibilities of MFI was revealed.
Characterization and Optimization of Ultrasound-induced Molecular Delivery In Vivo
Authors: Konofagou Elisa , Choi James , Wang Shougang , Morrison Barclay , Borden Mark
Published: May 2008

Current treatments of neurological and neurodegenerative diseases are limited due to the lack of a truly noninvasive, transient, and regionally selective brain drug delivery method. The brain is particularly difficult to deliver drugs to because of the blood-brain barrier (BBB). Over the past few years, we have been developing methods that combine Focused Ultrasound (FUS) and microbubbles in order to noninvasively, locally and transiently open the BBB so as to treat neurodegenerative diseases. In this paper, we will focus on the characterization of the type of molecular delivery that can be induced through the opened BBB. More specifically, we willl characterize important properties of the BBB opening such as its size and permeability using fluorescence and MR imaging techniques, respectively. The role of the microbubble type, size and concentration on the BBB diffusion properties, its reversibility and the pressure threshold for the opening will also be described in vivo. Finally, results will be shown in both non-transgenic (normal) and transgenic (Alzheimer's) mice in order to determine the variability of the properties of the opened BBB in the presence and absence of disease.
Echogenic liposomes for vasoactive gas delivery and inhibition of intima hyperplasia in atheroproliferative disease
Authors: Shaoling Huang Huang , McPherson David D. , Holland Christy K.
Published: May 2008

Our group has developed targeted echogenic liposomes (ELIP) for targeted ultrasound enhancement of atheroma as well as targeted therapeutic delivery. Nitric oxide (NO) has potent biological activities but is too labile for in-vivo vascular delivery. We have developed a methodology to entrap NO, cause local prolonged release and retain NO effect. NO-loaded ELIP were injected into the common carotid artery after balloon injury. Fourteen days later, the carotids were removed. Administration of NO-ELIP resulted in 51±6% inhibition of intimal thickening when compared with controls. Using a 6.0 MHz clinical Doppler diagnostic ultrasound system, we (Smith et al) have identified the optimal pressure threshold (MI 0.08) for NO diffusion from ELIP. Using these parameters we have enhanced vascular permeability of drugs and stem cells to help stabilize atherosclerotic plaques. We have developed a novel method for encapsulating NO into ELIP demonstrating their capacity for NO delivery, inhibition of intimal hyperplasia and controlled gas diffusion with ultrasound. This methodology provides a new approach for delivering a variety of bioactive gases to target tissues, which otherwise would have negligible effects when administered systemically.
Enhancement of microbubble mediated gene delivery by simultaneous exposure to ultrasonic and magnetic fields
Authors: Stride Eleanor , Porter Colin , Prieto Ana-Garcia , Pankhurst Quentin
Published: May 2008

It has been shown in previous studies that ultrasound mediated gene delivery can be greatly enhanced by the presence of contrast agent microbubbles and that transfection efficiency is highly dependent upon both bubble/cell separation and the ultrasound field parameters. It has also been shown that gene delivery can be promoted by exposing cells to a magnetic field in the presence of DNA conjugated to magnetic nanoparticles. The aim of this work was to investigate whether it was possible to combine the advantages of both these techniques. It was found that transfection of Chinese hamster ovary cells by naked plasmid DNA was enhanced by simultaneous exposure to ultrasound (40-cycle sinusoidal pulses, centre frequency 0.5-3MHz, peak negative pressure 0.25-1.5MPa, repetition frequency 1kHz for 10s) and a uniform magnetic field (3-5Nm-3) in the presence of two different microbubble/nanoparticle preparations. The first consisted of phospholipid-coated microbubbles mixed with micelles containing magnetic nanoparticles; the second of microbubbles which were themselves magnetically active. These preparations were found to be much more effective than either magnetic micelles or phospholipid-coated microbubbles alone. The mechanisms underlying these observations in terms of microbubble dynamics, the sensitivity to the ultrasound parameters and their significance for potential therapeutic applications will be discussed.
Trans-blood-brain barrier delivery of compounds at pharmacologically relevant molecular weights in the hippocampus of mice using Focused Ultrasound
Authors: Choi James , Wang Shougang , Tung Yao-Sheng , Morrison Barclay , Konofagou Elisa
Published: May 2008

Molecular engineering has recently contributed immensely to the development of neuropharmaceuticals. However, most of these compounds are greater than 400 Da, which are too large to traverse the brain's natural defense, the blood-brain barrier (BBB). In this study, molecular delivery at pharmacologically relevant molecular weights through a Focused Ultrasound (FUS) induced BBB opening was investigated. The left hippocampus of mice (n=13) was sonicated (frequency: 1.525MHz, pressure: 0.64MPa, duty cycle: 20%, duration: 1-min) in vivo through the intact skin and skull following intravenous injection of microbubbles (SonoVue®; 25μl). After sonication, otherwise BBB-impermeable fluorescent-tagged dextrans at various molecular weights were administered intravenously. Ex vivo fluorescent microscopy determined BBB opening by a significant increase in fluorescence in the left over the right hippocampus. The threshold for the molecular weights allowed through the hippocampal BBB was between 70k and 2,000k Da. Smaller compounds (i.e., 3k Da) were more spatially uniformly deposited throughout the hippocampus than larger (i.e., 70k Da) compounds. In conclusion, dextrans at neuropharmaceutically-relevant sizes were deposited in the left hippocampus of mice. This study thus demonstrates that FUS-induced BBB opening could allow neuropharmaceuticals previously impermeable to the BBB, such as inhibitors and antibodies, to target tissue they were designed to treat.
Simulation of the oscillation dynamics and translational motion of ultrasound contrast agents
Authors: Teterev Alexander , Rudak Larisa , Misuchenko Natalia
Published: May 2008

A numerical model has been developed to simulate the oscillatory dynamics and the translational motion of both free and encapsulated bubbles in an ultrasound field. The model allows for the compressibility of the surrounding liquid and the bubble shell, which makes it possible to model the bubble dynamics at high acoustic pressures. Simulations can be carried out either by solving Rayleigh-Plesset-type equations, or in the hydrodynamic approximation taking into account the rheological properties of the liquid and the shell, or by a combined method. In the latter case, the gas pressure at the bubble surface, which is found from the gas-dynamic problem, is used as an input parameter for Rayleigh-Plesset-type equations at every time layer. The resulting radius of the bubble is then used as the boundary condition for the gas-dynamic equations. The model is a handy and flexible tool to investigate the effect of different factors on the oscillatory dynamics of the bubble, such as the thickness of the bubble shell, the rheological properties of the shell, and the translational displacement of the bubble. Using the developed model, the resonance frequency and translational displacement of contrast agents were numerically estimated.