bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of partition height and sound masking on speech privacy and occupant acceptance in open plan offices: Results of surveys and field tests.
Authors: Pettyjohn Steven D.
Published: July 2011

This paper combines the results of two studies done to provide speech privacy and occupant acceptance of open plan office furniture and sound masking. In the first study, the occupants of open plan offices in six buildings were surveyed to learn what they thought of acoustical conditions. Acoustics was not the only area addressed as temperature was another topic. Statistical evaluation of the results showed that acceptance of their cubicle design was directly proportional to the height of the panels. F-tests did not show a correlation with any other factor such as the presence of sound masking systems. In the second project, the influence of a sound masking system on speech privacy was evaluated. A decision was made to install low height cubicle panels to permit maximum interaction in a call center. Sound measurements were made in spaces with and without sound masking systems and informal surveys done to understand occupant satisfaction and the influence of sound masking on speech privacy and the ability of occupants to concentrate on their work. A summary of the survey and analysis is provided along with the results from sound tests in spaces with and without sound masking and with various cubicle panel heights.
Case study: Improving speech privacy in a cathedral ceiling open office.
Authors: Foulkes Timothy , Elliott William
Published: July 2011

A large indoor food market with a wood cathedral ceiling was adapted for use as an office space. A mezzanine level was added as part of the office fitup. The space was entirely open plan including the conference rooms, which had glass screen walls but no ceilings. The acoustic problems included excess loudness, lack of privacy, difficulty with telephone communications, and poor room acoustics in the conference room. This was a Green project, which put an emphasis on natural lighting and ventilation, and organic materials. Careful consideration of available products on the market led to some creative recommendations for acoustic upgrades.
Whistle variation is associated with surface behavior in the Guyana dolphin (Sotalia guanensis).
Authors: May-Collado L. J.
Published: July 2011

Guyana dolphins emit whistles with the widest frequency range ever reported today (1.34 to 48.4 kHz). Distance between populations has been suggested as an important factor promoting whistle variation in this dolphin species. However, other factors known to promote intra-specific whistle variation among delphinids such as behavior have not been explored yet in Guyana dolphins. Behavior has been shown as important factor promoting whistle variation in many whistling species, and thus it should be taken into consideration in comparative studies of dolphin communication. Here, I study the relationship between whistle structure and surface behavioral states (travel, foraging, and social behaviors) of Guyana dolphins from a small resident population in Costa Rica. Behavior had a significant effect on whistle duration and whistle minimum, delta, ending, and start frequencies variables. Moreover, more than 47% of the whistles were correctly classified to their corresponding surface behavior. These results indicate that not only behavior is an important factor contributing to intra-specific whistle variation in Guyana dolphins but that behavior is an important variable to describe any acoustic study which goal is to compare populations.
Audibility of the cricket, acheta domesticus, obtained from auditory evoked potentials.
Authors: Guisti Bailee , White Shanna , Yonovitz Al
Published: July 2011

For crickets, auditory and vibratory communication is important in reproductive behavior, agonistic interactions, detection of predators, and acoustic orientation in the environment. In the cricket, the forelegs house the specialized tibial organs that comprise the tympanal structures. Much of the information regarding the auditory sensitivity of the receptors of the foreleg is the result of study of individual receptor cells. The whole receptor population of the tympanal organ covers the frequency range from at least 2000 k–70 kHz. Little information is available on the neuronal and physiological properties of the brain to acoustic signals. The purpose of this study was to record auditory evoked potentials on the surface of the cricket brain, Acheta domesticus. Electrodes were placed onto the brain of crickets and signals were amplified and averaged over the range 100 ms. Sinusoidal stimuli covered a range between 4 and 48 kHz. Waveform morphology and input-output curves for the cricket will be shown.
Combining light and sound to guide and monitor ultrasound therapy.
Authors: Bossy Emmanuel
Published: July 2011

Ultrasound therapy makes use of high-intensity focused ultrasound (HIFU) to noninvasively necrose targeted soft tissues without damage to overlaying or surrounding tissues. Two main challenges in implementing HIFU therapies are treatment guidance and treatment monitoring. In this paper, we discuss the use of techniques combining optics and acoustics to guide/monitor HIFU, as alternatives or complements to more conventional approaches based on magnetic resonance imaging or ultrasound imaging. Recently, several publications demonstrated some potential for photoacoustic imaging in the field of HIFU therapy, both for guidance and/or monitoring [Funke et al., Apple Phys. Lett. 94(5), (2009); Chitnis et al., JBO 15(2), (2010); Cui et al., JBO 15(2), (2010)]. In the first part of the presentation, we will illustrate the use of a dual-mode linear array for photoacoustic-assisted ultrasound therapy. The same elements of the probe are used both as photoacoustic detectors and HIFU emitters, driven by a dedicated multichannel electronics. In the second part of the presentation, monitoring the formation of a HIFU lesion will be demonstrated using transient optoelastography, a technique based on the optical detection of shear motion generated by the acoustic radiation force.
Wave space array methods for aeroacoustic testing.
Authors: Bahr Chris , Sheplak Mark , Cattafesta Lou , Li Jian
Published: July 2011

Phased array beamforming is commonly applied to assess the spatial distribution of noise sources in aeroacoustic wind tunnel testing, generally with planar microphone arrays. As classically applied with a conventional beamforming algorithm, results can suffer contamination due to cross-flow over the array face in the wind tunnel test environment. When the cross-flow fluctuations are statistically independent from microphone-to-microphone, diagonal removal can be applied to the cross-spectral matrix to negate this contamination. However, when these fluctuations are correlated, diagonal removal fails to recover the acoustic field of interest. As has been previously demonstrated, the wave space representation of an observed pressure field readily separates cross-flow hydrodynamic fluctuations from the observed acoustic field, when applied to low speed wind tunnel tests. The authors build on existing research to construct beamforming methods in wave space to leverage this separability. The implications of aeroacoustic beam-forming analysis in wave space as applied to plane and spherical waves are discussed, with focus on filtering hydrodynamic fluctuations from acoustic waves, as well as determining levels of the resultant filtered pressure field. Theoretical development is presented, followed by numerical analysis and experimental results from the University of Florida Aeroacoustic Flow Facility.
Generalized inverse beam-forming in applications to aeroacoustic problems.
Authors: Suzuki Takao
Published: July 2011

Current source-detection techniques (i.e., beam-forming) still suffer with resolving aerodynamic sources, which are typically distributed, highly directive, and partially coherent. Improvement of these tools helps us evaluate new acoustic technologies. We are developing an algorithm, called L1 generalized inverse beam-forming, to resolve coherent/incoherent, distributed, and multipole sources. To extract each coherent signal, a cross spectral matrix is decomposed into eigenmodes. Subsequently, the complex source-amplitude distribution that recovers each eigenmode is solved using L1-norm generalized inverse techniques using iteratively re-weighted least squares with reference solutions including multipoles as well as a monopole. The capabilities of the proposed algorithm are demonstrated using benchmark problems by comparing with several existing beam-forming algorithms, and it is found that distributed sources as well as dipoles with arbitrary orientation can be identified regardless of coherency with another source. The resolution is comparable to existing deconvolution techniques, such as DAMAS or CLEAN, and the computational cost is only several times more than that of DAMAS2. The proposed algorithm has also been applied to aeroacoustic test data including noise associated with jet-flap interaction, noise from a single round jet, and duct acoustics with flow, and these results are discussed in this talk.
Results from a prototype tetrahedral array for tracking sound sources in shallow water.
Authors: Gemba Kay , Nosal Eva-Marie
Published: July 2011

A passive acoustic system aimed at tracking sound sources in harbor and near-shore environments is currently being developed. At the expense of decreased directivity for the same number of elements, volumetric arrays have an advantage over line or planar arrays since beam patterns can be steered both vertically and horizontally. In this paper, the tracking performance of a tetrahedral array for mid- to high-frequency (1–40 kHz) sound sources is evaluated. Modeled tracking performance is compared with measured results obtained using a prototype array in a controlled environment. The performance of several different processors is being investigated, and difficulties associated with shallow-water environments including complicated and time-varying multipath structure and varying background noise conditions are considered. Primary criteria for selecting processors of interest are robustness and computational efficiency. [This work is funded by the U.S. Department of Homeland Security through the Center for Island, Maritime and Extreme Environment Security.]
Optimum array design to maximize fisher information for bearing estimation in spatially correlated noise environment.
Authors: Tuladhar Saurav R. , Buck John R.
Published: July 2011

Source bearing estimation is a common application of linear sensor arrays. The Cramer–Rao bound (CRB) sets a lower bound on the achievable mean square error (MSE) of any unbiased bearing estimate. In the white noise case, the CRB is minimized by placing half of the sensors at each end of the array [MacDonald and Schultheiss, JASA (1969)]. However, many realistic ocean environments have a mixture of both white noise and correlated noise. In many shallow water environments, the correlated ambient noise can be modeled as cylindrically (two-dimensionally) isotropic. This research designs a fixed aperture linear array to maximize the fisher information for bearing estimation under these noise conditions. The optimum array is designed to maximize the minimum fisher information over an a priori bearing range. The elements of the optimal array are located closer to the array ends than uniform spacing, but are not so extreme as in the white noise case. The optimal array results from a trade off between minimizing the measured noise and maximizing the array bearing sensitivity. Depending on the source bearing, the resulting improvement in MSE performance over a uniform array is equivalent to a 3 to 5 dB improvement in input SNR. [Work supported by ONR.]
Advantages and limitations of the fiber-optic probe hydrophone for characterization of shock waves in water.
Authors: Pishchalnikov Yuri A. , Gaitan D. Felipe , Einert Mark S. , Bailey Michael R. , Sapozhnikov Oleg A. , McAteer James A.
Published: July 2011

The fiber-optic probe hydrophone (FOPH) (RP Acoustics, Leutenbach, Germany) is the standard for shock wave measurement, as it is omnidirectional with a flat frequency response ranging from static pressure to several megahertz. The FOPH calibration is determined from the equation of state of water, the optical refractive index of the glass/water interface, and the dc level of reflected light. We tested the accuracy of this calibration by placing the sensitive tip of the FOPH under static pressure up to 140 MPa. The FOPH gave accurate readings of applied static pressures provided there were no defects in the fiber. Defects (cracks and chips) in the glass fiber were difficult to control and could occur during routine handling: stripping, cleaving, or mounting. Such defects led to spurious spikes in measured waveforms. Defects were also caused by cavitation damage to the fiber. In addition, cavitation bubbles on the fiber compressed the fiber and resulted in distorted waveform measurement. Thus, although the FOPH is omnidirectional and accurate from zero to tens of megahertz, it is also susceptible to minute defects in the fiber and to cavitation bubble collapse along the fiber. [This work was supported in part by NIH-DK-43881 and by Impulse ACPT Contract No. W9113M-07-C-0178.]
Experimentally validated multiphysics computational model of refracting shock wave lithotripter.
Authors: Fovargue Dan , Mitran Sorin , Sankin Georgy , Smith Nathan , Zhong Pei
Published: July 2011

We will present a computational model of the focusing of an electromagnetically induced pressure pulse by an acoustic lens and subsequent shock wave formation. Linear elasticity equations for the lens are solved simultaneously with Euler hydrodynamic equations for water considered to be a compressible medium with a Tait equation of state. The adaptive mesh refinement model allows both three-dimensional and two-dimensional axisymmetric computations. A number of coupling approaches at the lens-water interface are investigated by comparison to experimental results: transfer only of pressure boundary condition, coupling of displacement velocities, and a buffer linear elasticity region in the water immediately adjacent to lens. The model is validated against single-medium measurements (water or lens material), and the complete experimental shock wave formation process. Initial results from a crack propagation model in stone simulants placed at the lithotripter focus will also be presented.
Statistical analysis of a finite-amplitude sinusoid.
Authors: Shepherd Micah R. , Hanford Amanda D. , Gee Kent L.
Published: July 2011

Pressure amplitude statistics have been used in several experimental studies of jet and rocket noise to indicate and study nonlinear acoustic propagation. Statistics of pressure amplitude time derivatives have also been shown to be sensitive to nonlinearity in noise. To illustrate the sensitivity of statistics to nonlinearity, the nonlinear propagation of a pure sinusoid is considered. The probability density function, standard deviation, skewness, kurtosis, and crest factor are computed for both the amplitude and amplitude time derivatives as a function of distance. The amplitude statistics vary only in the postshock realm, while the amplitude derivative statistics vary rapidly in the preshock realm. Using statistical analysis also suggests that the sawtooth onset distance can be considered to be earlier than previously realized.
Comparison of prosodic properties of intonation in beijing Mandarin and Taiwan Mandarin.
Authors: Kuang Jianjing , Kuo Grace
Published: July 2011

In many studies, Beijing Mandarin and Taiwan Mandarin are considered to be identical because they share the same lexical tone system (except for a subtle difference in tone 3). However, native speakers of the two dialects can easily differentiate one from the other. This study investigates the intonation patterns of the two dialects; it will be shown that there are important prosodic differences in the boundary cues and use of pitch. The data were collected from recordings of “Little Red Riding Hood” read by eight native speakers (four from Beijing, and four from Taiwan). The preliminary results show that Beijing Mandarin and Taiwan Mandarin have different boundaries cues: at the phrase level, although both Beijing and Taiwan Mandarin have final lengthening, Taiwan Mandarin has no intensity reduction and Beijing Mandarin has a high boundary tone. At the sentence level, obvious lengthening and stress placement on final particles are observed in Taiwan Mandarin, while those particles are reduced in Beijing Mandarin. Furthermore, the pitch trajectory differed in some sentence types, e.g., pitch declination after nuclear-accented wh-words in Taiwan Mandarin but not Beijing Mandarin.
Measuring linguistic and functional performance of hand-held speech-to-speech interpreters.
Authors: Bernstein Jared , Rosenfeld Elizabeth
Published: July 2011

In 2011, voice-in/voice-out interpretation in several language pairs is available for mobile phones. Computers with internet access can translate text between many language pairs. These machines interpret and translate quickly, but not always accurately. If current portable devices support basic bidirectional communication for travel or in commercial transactions, what is the future of second language education? This work evaluates the performance of hand-held interpretation analytically and functionally. A study was conducted using current hand-held devices for English-Spanish and Spanish-English interpretation. Ten Spanish and ten English monolinguals performed three simple interactive functional tasks designed to assess different levels of spoken language proficiency. The resulting performances were transcribed then processed by a machine translator and spoken into a hand-held machine interpreter. Analytic measures (word error rate, Bleu, intelligibility) were made comparable for the three processes (recognition, translation, synthesis), in both the Spanish-English and English-Spanish directions to find the weak links in the interpretation chain. The data also provided an estimate of the functional level of current hand-held devices with reference to second language communication standards used in applied linguistics.
Parsing the ambiguity of casual speech: “He was like” or “He’s like”?
Authors: Brenner Dan , Warner Natasha , Ernestus Mirjam , Tucker Benjamin V.
Published: July 2011

Reduction in casual speech can create ambiguity, e.g., “he was” can sound like “he’s.” Before quotative “like” (“so she’s/she was like…”), it was found that there is little accurate acoustic information about the distinction in the signal. This work examines what types of information (acoustics of the target itself, speech rate, coarticulation, and syntax/semantics) listeners use to recognize such reduced function words. We compare perception studies presenting the targets auditorily with varying amounts of context, presenting the context without the targets, and a visual study presenting context in written form. Given primarily discourse information (visual or auditory context only), subjects are strongly biased toward past, reflecting the use of quotative “like” for reporting past speech. However, if the target itself is presented, the direction of bias reverses, indicating that listeners favor acoustic information within the target (which is reduced, sounding like the shorter, present form) over almost any other source of information. Furthermore, when the target is presented auditorily with surrounding context, the bias shifts slightly toward the direction shown in the orthographic or auditory-no-target experiments. Thus, listeners prioritize acoustic information within the target when present, even if that information is misleading, but they also take discourse information into account.
Explaining boundary perception in spontaneous French conversation: Acoustic and phrasal metrics.
Authors: Smith Caroline L.
Published: July 2011

Prosodic structure in speech derives from both linguistic structure, particularly syntax, and performance factors such as speech rate. The combination of influences means that predicting the structure of a spontaneous utterance remains a major challenge. One approach has been to survey listeners and take their perceptions as the basis for analysis [e.g., Cole et al., Lab.Phonol. (2010)]. A study of this type in French compared perceptions of two types of spontaneous speech: informal conversation and more formal journalistic discussion. 25 naive native speakers of French listened to recordings of both types and indicated where they perceived boundaries between groups of words. Their responses were then compared to acoustic measurements and analyzes of the phrasal structure of the conversations. The presence of a pause and a rise in F0 were the most reliable acoustic correlates of a perceived boundary. Preliminary analyzes of phonological phrase structure suggest that the thresholded boundary weight hypothesis of Breen et al. [2010 Lang. Cog. Proc.] is a promising metric for explaining the pattern of boundary perception in these data. Locations were more often perceived as boundaries when the sum of the sizes of just-completed and upcoming constituents (measured in numbers of phonological phrases) is larger.
Boundary enhancement of a solid cylinder backscattering response: Experiments and modeling.
Authors: La Follett Jon R. , Marston Philip L.
Published: July 2011

The presence of a reflecting boundary modifies the free-field backscattering response of an object. Boundary reflections increase the number of available paths for scattered sound to return to a source-receiver. In the present work, high-frequency tank experiments on solid aluminum cylinders demonstrate a strong boundary related backscattering response that is present for a broad range of aspect angles. To study the effects of close proximity to a flat reflecting boundary, cylinders were suspended in water near the tank’s air-water interface. Targets were insonified from below at grazing incidence. Monostatic measurements were made as the cylinders were rotated in a plane parallel to the boundary. Some aspects of this response could be understood by modeling the region of water bounded by the cylinder top and the air-water interface as a quasi-2-D waveguide. Sound incident on this region of decreasing water thickness can be reflected as from a seamount. The backscattered amplitude is strongly affected by the threshold frequency for propagation in the gap between the cylinder and the adjacent flat surface. Experiments show that the behavior of this response, as a function of target depth and aspect angle, is in qualitative agreement with this waveguide model. [Work supported by ONR.]
Acoustic biomass estimation and uncertainty of Pacific hake and Humboldt squid in the Northern California current in 2009.
Authors: Thomas Rebecca , Stewart Ian , Chu Dezhang , Pohl John , Cooke Ken , Grandin Chris , de Blois Stephen
Published: July 2011

The population of Humboldt squid (Dosidicus gigas) has seen an explosion in the Eastern North Pacific over the last several years. The species has gone from being rarely seen in the waters off OR, WA, and BC to becoming a major predator in the marine food web in this area. This population explosion has the potential to cause large impacts in major fish stocks. The biennial 2009 Joint U.S.-Canada Pacific hake (Merluccius productus) acoustic trawl survey also noted large amounts of Humboldt over much of the survey area. Because Humboldt squid could be acoustically confused with Pacific hake, and because the presence of Humboldt squid disrupted the normal shoaling pattern of hake, an estimated depth threshold was used to help distinguish Humboldt squid from hake. Accordingly, the biomass estimate of Pacific hake for 2009 was less certain. Several methods were explored to quantify the uncertainty and assess the reliability of the hake biomass estimate.
Challenges in the quantitative assessment of anthropogenic sound in marine environments.
Authors: Siderius Martin , Zurk Lisa
Published: July 2011

Concerns about the effects of anthropogenic sounds in aquatic environments have increased over the past 2 decades. There is particular concern with the impact to species that are endangered or those that rely on sound for foraging, navigating, and to detect prey and predators. One of the challenges to quantitative assessment is simply characterizing all environments with potentially harmful sound sources and identifying the impacted species (type and population density). In addition, there are challenges to setting the criteria for physiological and nonphysiological (i.e., behavioral) impacts. Environments vary widely from the deep ocean where navy and commercial sonar systems mostly operate to shallow water (including rivers) where construction sites are often located and activities such as pile driving occur. There are challenges related to both the measurement and the prediction of impact in these environments. Measurements are needed to determine if sound levels and species type and density are as expected. Prediction is required to extrapolate beyond the direct measurements and to define a zone-of-influence to determine the overall impact. Acoustic analysis includes accurately describing the sound mechanisms and the sound propagation within the zone-of-influence. The focus of this presentation will be on the acoustic challenges related to quantitative assessment.
Field applications of broadband acoustic scattering techniques for quantifying zooplankton distribution, abundance, and size.
Authors: Lawson Gareth L. , Lavery Andone C. , Wiebe Peter H. , Copley Nancy J.
Published: July 2011

Discriminating among sources of scattering remains a key problem in ecological applications of active acoustics. This is particularly true in studies of zooplankton, which are often found in communities of heterogeneous species composition, and in the deployment of acoustics on autonomous platforms, where independent sampling with nets to ground-truth acoustic observations is often not feasible. Broadband measurements can provide substantial improvements in species discrimination by characterizing more fully the frequency spectrum of scatterers relative to traditional single- and multi-frequency narrowband techniques. Here, we present findings from a series of three cruises to the margins of Georges Bank examining patchiness in the distribution of krill and other zooplankton, as well as interactions with predators (fish, seabirds, and marine mammals). A heavily modified commercially-available broadband system spanning a frequency band of 30–600 kHz, with some gaps, was deployed in a towed body to depths of 200 m. Concurrent measurements made with a surface-towed multi-frequency system (43, 120, 200, and 420 kHz) along with ground-truthing information from depth-stratified net sampling and a video plankton recorder allow an assessment of the strengths and limitations of broadband methods for remotely discriminating among sources of scattering and for estimating the abundance and size of animals.
The advantage of FM slide signals for active acoustic systems used for fisheries studies.
Authors: Ehrenberg John E. , Johnston Samuel V.
Published: July 2011

A key requirement for many active acoustics systems used for fisheries or biological oceanographic data collection is to provide high spatial resolution while maximizing the range for which useful data are obtained. Unfortunately, most systems in use today use cw pulse transmit signals for which the user must trade-off range resolution with output signal-to-noise, which determines the maximum useful range at which data can be collected. This paper describes the application of a different type of signal, the FM slide or chirp, for fisheries and oceanographic acoustic assessment. Compared to the cw pulse based systems, acoustic systems that use FM slide signals with the corresponding matched filter processing can achieve significantly better spatial resolution without sacrificing maximum range. The explanation of why the FM slide signal achieves this improved performance as well as a discussion of some of the factors that must be considered when implementing this signal type are described. Laboratory measurements and field results are presented that show the advantages of the FM slide for real world assessment studies.
Passive acoustics as a monitoring tool for evaluating oyster reef restoration.
Authors: Zenil Hilde P. , Encomio Vincent G. , Gilmore R. Grant
Published: July 2011

Passive acoustics uses naturally occurring sounds produced by marine organisms to study their behavior, biology, and location. Ambient marine sounds are known to vary from place to place, and these sounds can be used to detect differences in habitats. Oyster toadfish, naked goby, mud crabs, and snapping shrimps inhabit oyster reefs, and they are known to produce sounds. In an oyster reef, the combination of sounds produced by organisms’ communication, feeding, or moving may produce a unique acoustic signature. Therefore, individual acoustic signatures of oyster reefs may convey information about the habitat quality and the organisms that inhabit them. Three sites along the Saint Lucie Estuary, Florida were acoustically monitored. Restored and natural reefs were recorded for 5-min using a hydrophone. Acoustic signatures were compared using spectra [(frequency (Hz) versus intensity (dB)] overlays. Preliminary results showed that shortly after restoration, acoustic signatures from the natural and restored reefs differed. As time progresses, the acoustic signature of a fully restored reef may resemble that of the natural reef, representing a convergence of restored and natural habitats. Passive acoustics has the potential to provide a new methodology to rapidly monitor oyster reefs and other ecosystems such as coral reefs and rocky reefs.
Multi-frequency species classification of acoustic-trawl survey data using semi-supervised learning and class discovery.
Authors: Woillez Mathieu , Ressler Patrick H. , Wilson Chris D. , Horne John K.
Published: July 2011

Data from towed samplers (e.g., trawls) are invaluable for validation of species classifications in fisheries acoustics surveys but may be sparse or unavailable and not all backscatter is classified. This situation is often encountered when little sampling effort is focused on confirming identities of organisms other than target species. To address this situation, a generalized Gaussian mixture model was developed to classify multi-frequency acoustic data under the assumption that some classes of organisms may be unknown. The classification algorithm, based on semi-supervised learning with class discovery, was applied to acoustic survey data collected in the eastern Bering Sea during summers of 2004 and 2006–2008. The major known scattering classes (pollock and euphausiids) were objectively detected and mapped, and compared well with traditional subjective classification methods (i.e. scrutinizing) by acoustic survey analysts. Two other major classes with distinct frequency responses were also identified, occurring mostly in the upper 15–60 m of the water column. The classification results are used to describe these unknown groups, to optimize a field sampling plan to identify their constituents, and to determine whether these groups provide important information about the Bering Sea ecosystem. [Work supported by Alaska Fisheries Science Center, North Pacific Research Board and the NSF.]
The use and efficacy of acoustic survey methods as applied to a mixed aquatic community: The deep scattering layer of the California Current.
Authors: Davison Peter , Lara-Lopez Ana , Koslow J. Anthony
Published: July 2011

Concurrent acoustic and trawl data were collected in 2008 near Point Conception to compare the abundance estimates of mesopelagic micronekton obtained with these two methods. Acoustic data were obtained with a calibrated EK-60 equipped with four frequencies (38, 70, 120, and 200 kHz). Animals were collected with a midwater trawl. Target strength (TS) models were created of the animals collected by the trawl, and animals were assigned to acoustic groups based on the frequency spectrum of their modeled TS. The mean spectra of the acoustic groups were used with non-negative least squares inverse methods to estimate abundance from the multi-frequency volume scattering. The resulting acoustic abundances of each group were compared to the trawl catches, and capture efficiency of the net was estimated. The accuracy of the inverse method was tested with a Monte Carlo analysis of an artificial echogram. The accuracy of the forward modeling was tested via comparison to single targets recorded by the EK-60. [Work supported by NASA, CCE-LTER, and The Moore Foundation.]
Resonance classification of fish with swimbladders using a modified commercial broadband echosounder.
Authors: Chu Dezhang , Stanton Timothy K. , Jech J. Michael , Irish James D.
Published: July 2011

A towed commercial sub-bottom profiler acoustic system has been adapted for studying fish with swimbladders. It contains broadband acoustic channels collectively spanning the frequency range 1.7–100 kHz, with some gaps. Using a pulse-compression technique, the range resolution of the echoes can be significantly improved, allowing high-resolution imaging of patches and resolving fish near the seafloor. Measuring the swimbladder resonance at the lower frequencies eliminates major ambiguities normally associated with the interpretation of fish echo data: (i) The resonance frequency can be used to estimate the volume of the swimbladder (inferring the size of fish), (ii) signals at the lower frequencies do not depend strongly on the orientation of the fish, and (iii) spectral analysis of backscattered signals can be used to classify different sizes and/or species of fish. At-sea studies of Atlantic herring and other fish and zooplankton species demonstrate the potential for routine measurements of fish size and density, with significant improvements in accuracy over traditional high-frequency narrowband echosounders. New techniques for quantitative use of broadband systems are presented, including broadband calibration and relating target strength and volume-scattering strength to quantities associated with broadband signal processing.
Quantum Simulation of Frustrated Classical Magnetism in Triangular Optical Lattices
Authors: Struck J. , Ölschläger C. , Le Targat R. , Soltan-Panahi P. , Eckardt A. , Lewenstein M. , Windpassinger P. , Sengstock K.
Published: July 2011

An optical lattice of trapped atoms provides a tractable and tunable setup to study complex magnetic interactions.
Silencing of thehPOT1gene by RNA inference promotes apoptosis and inhibits proliferation and aggressive phenotype of gastric cancer cells, likely through up-regulating PinX1 expression
Authors: Wan Shun-Mei , Tie Jun , Zhang Ya-Fei , Guo Jun , Yang Liu-Qin , Wang Jun , Xia Shi-Hai , Yang Shi-Ming , Wang Rong-Quan , Fang Dian-Chun
Published: July 2011

Background

The human protection of telomeres 1 (hPOT1) protein, a single-strand telomeric DNA binding protein, plays an important role in telomere protection and telomere length regulation. However, its effect on invasion of gastric cancer remains unclear.

Aims

To explore the role of hPOT1 in the proliferation and invasion of gastric cancer cells.

Methods

The gastric expression of hPOT1 was examined in normal gastric mucosa (n=25), intestinal metaplasia (n=20), gastric dysplasia (n=20) and gastric cancer (n=150) by immunohistochemistry. The mean optical density (MOD) of the immunostaining was determined by semi-quantitative image analysis. The role of hPOT1 in the cell proliferation, apoptosis and invasion of gastric cancer 7901 cells was determined by means of the RNA interference (RNAi) of hPOT1 mRNA. The effects of hPOT1 RNAi on the expression of hPinX1 and hTERT were detected with western blotting.

Results

The hPOT1 MOD was progressively increased from the normal mucosa to intestinal metaplasia, dysplasia, and gastric cancer. An increased hPOT1 expression significantly correlated with tumour serosal invasion, node metastasis and advanced stage. Transfection of hPOT1 siRNA into SGC-7901 cells led to a decrease in cell proliferation, colony formation and invasion, and also an increase of apoptosis. An up-regulation of hPinX1 and down-regulation of hTERT were found in gastric cancer cells with hPOT1 siRNA.

Conclusions

Increased hPOT1 expression is associated with an advanced tumour stage. hPOT1 RNAi inhibits proliferation and invasion, and induces apoptosis of gastric cancer cells. The effects of hPOT1 RNAi seem to be functionally linked to up-regulation of PinX1 and down-regulation of hTERT.
Formulations of the endophytic bacteriumBacillus subtilisTu-100 suppressSclerotinia sclerotiorumon oilseed rape and improve plant vigor in field trials conducted at separate locations
Authors: Hu Xiaojia , Roberts Daniel P. , Maul Jude E. , Emche Sarah E. , Liao Xing , Guo Xuelan , Liu Yeying , McKenna Laurie F. , Buyer Jeffrey S. , Liu Shengyi
Published: July 2011

Sclerotinia sclerotiorum causes serious yield losses in crops in the People’s Republic of China. Two formulations of oilseed rape seed containing the bacterium Bacillus subtilis Tu-100 were evaluated for suppression of this pathogen in field trials conducted at two independent locations. The pellet formulation significantly reduced disease (incidence and disease index) and increased plant dry mass, while the wrap formulation significantly reduced disease incidence and significantly increased plant dry mass at both field locations. Mean seed yield per 120 plants with both formulations of isolate Tu-100 was significantly greater than the appropriate controls, but at only one of the locations. Both formulations provided stable B. subtilis Tu-100 biomass (≥105CFU·g–1) and seed germination (≥85%) over a 6 month period at room temperature. Polymerase chain reaction and DNA sequence analysis identified ituC and ituD, and bacAB and bacD in the genome of isolate Tu-100. These genes are involved in the biosynthesis of iturin and bacilysin. Iturin was detected in culture filtrates from isolate Tu-100, with thin layer chromatography. Detection of bacilysin was not attempted. Experiments reported here indicate the commercial viability of B. subtilis Tu-100 for suppression of S. sclerotiorum on oilseed rape.
Two ATP phosphoribosyltransferase isozymes ofGeobacter sulfurreducenscontribute to growth in the presence or absence of histidine and under nitrogen fixation conditions
Authors: Aklujkar Muktak
Published: July 2011

Bacteria of the Geobacter clade possess two distinct ATP phosphoribosyltransferases encoded by hisGLand hisGS+hisZ to catalyze the first reaction of histidine biosynthesis. This very unusual redundancy was investigated by mutational analysis. The hisGL, hisGS, and hisZ genes of Geobacter sulfurreducens were deleted, effects on growth and histidine biosynthesis gene expression were evaluated, and deficiencies were complemented with plasmid-borne genes. Both hisGLand hisGS+hisZ encode functional ATP phosphoribosyltransferases. However, deletion of hisGLresulted in no growth defect, whereas deletion of hisGSdelayed growth when histidine was not provided. Both deletions increased hisZ transcript abundance, and both ΔhisGSand ΔhisZ mutations increased hisGLtranscript abundance. Growth with HisGLalone (due to deletion of either hisGSor hisZ) was better under nitrogen fixation conditions than when ammonium was provided. Deletion of hisZ caused growth defects under all conditions tested, with or without exogenous sources of histidine, with different patterns of histidine biosynthesis gene expression under each condition. Taken together, the data indicate that G. sulfurreducens depends primarily on the HisGSZ isozyme as an ATP phosphoribosyltransferase in histidine biosynthesis, and for other functions when histidine is available; however, HisGLalso functions as ATP phosphoribosyltransferase, particularly during nitrogen fixation.
Isolation of high-quality total RNA from rumen anaerobic bacteria and fungi, and subsequent detection of glycoside hydrolases
Authors: Wang Pan , Qi Meng , Barboza Perry , Leigh Mary Beth , Ungerfeld Emilio , Selinger L. Brent , McAllister Tim A. , Forster Robert J.
Published: July 2011

The rumen is one of the most powerful fibrolytic fermentation systems known. Gene expression analyses, such as reverse transcription PCR (RT-PCR), microarrays, and metatranscriptomics, are techniques that could significantly expand our understanding of this ecosystem. The ability to isolate and stabilize representative RNA samples is critical to obtaining reliable results with these procedures. In this study, we successfully isolated high-quality total RNA from the solid phase of ruminal contents by using an improved RNA extraction method. This method is based on liquid nitrogen grinding of whole ruminal solids without microbial detachment and acid guanidinium – phenol – chloroform extraction combined with column purification. Yields of total RNA were as high as 150 µg per g of fresh ruminal content. The typical large subunit/small subunit rRNA ratio ranged from 1.8 to 2.0 with an RNA integrity number (Agilent Technologies) greater than 8.5. By eliminating the detachment step, the resulting RNA was more representative of the complete ecosystem. Our improved method removed a major barrier limiting analysis of rumen microbial function from a gene expression perspective. The polyA-tailed eukaryotic mRNAs obtained have successfully been applied to next-generation sequencing, and metatranscriptomic analysis of the solid fraction of rumen contents revealed abundant sequences related to rumen fungi.
COMMENSURABILITY EFFECTS ON DIFFUSION PROCESS IN STEPPED STRUCTURES
Authors: LACHTIOUI Y. , MAZROUI M. , BOUGHALEB Y.
Published: July 2011

This study deals with the investigation of diffusion process of one-dimensional system with steps for adsorbates interacting via the nearest-neighbor harmonic forces. The results are obtained from numerical studies, utilizing the method of stochastic Langevin dynamics. To study commensurability effects and the role of steps in the behavior of the diffusing particles, we have computed the diffusion coefficient for large concentrations and several interaction strengths. Our numerical results show that the diffusive behavior is reduced for commensurate structure case when the ground state has only one particle per one period of the substrate potential and enhanced for incommensurate density. Furthermore, the dynamic is qualitatively similar to that obtained in the case of no steps but with a clear reduction of the diffusion rate. Implications of these findings are discussed.
BERRY PHASE OF ATOM-FIELD SYSTEM IN INTERACTING FOCK SPACE
Authors: DAS P. K. , HALDAR PRASANTA
Published: July 2011

Starting with the interaction of interacting field and a two level atom we observe that the atom-interacting field system acquires a space parameter dependent Berry phase after the phase parameter slowly changes and ultimately returns to its initial form.
INVESTIGATIONS OF ELECTRON-PARAMAGNETIC-RESONANCE PARAMETERS OF OCTAHEDRAL (CrO6)9- and (MnO6)8- CLUSTER IN MgTiO3:Cr3+, SrTiO3:Cr3+ AND SrTiO3:Mn4+ CRYSTALS
Authors: WANG MINJIE , ZHU LIANXUAN , DANG JIANLIANG
Published: July 2011

The complete high-order perturbation formulas are established by both crystal-field (CF) and charge-transfer (CT) mechanisms. The EPR g factors of MgTiO 3: Cr 3+, SrTiO 3: Cr 3+ and SrTiO 3: Mn 4+ crystals are calculated from the formulas. The calculations of the EPR g factors are in agreement with the experimental values. The contribution rate of the CT mechanism (|ΔgT/ΔgF|) to EPR parameters, increases with the growth of the valence state for the 3dn ions in the crystals. For the higher valence state 3d3 ion Mn 4+ in crystals, the explanation of the EPR parameters reasonably involves both CF and CT mechanisms. The g values are also given from one-spin-orbit-parameter model and crystal-field (CF) mechanism for comparison.
LEPTOGENESIS AND LHC PHYSICS WITH TYPE III SEE-SAW
Authors: CHEN SHAO-LONG , HE XIAO-GANG
Published: July 2011

The See-Saw mechanism provides a nice way to explain why neutrino masses are so much lighter than their charged lepton partners. It also provides a nice way to explain baryon asymmetry in our universe via the leptogenesis mechanism. In this talk we review leptogenesis and LHC physics in a See-Saw model proposed in 1989, now termed the Type III See-Saw model. In this model, SU(2)L triplet leptons are introduced with the neutral particles of the triplets playing the role of See-Saw. The triplet leptons have charged partners with standard model gauge interactions resulting in many new features. The gauge interactions of these particles make it easier for leptognesis with low masses, as low as a TeV is possible. The gauge interactions also make the production and detection of triplet leptons at LHC possible. The See-Saw mechanism and leptogenesis due to Type III See-Saw may be tested at LHC.
INFLATION IN STRING THEORY
Authors: KIM HANG BAE
Published: July 2011

Recent developments in string theory such as flux compactifications and moduli stabilization by non-perturbative effects of D-branes provided a solid framework where we discuss the realization of inflation in string theories. We review two prototype models, modular inflation and brane inflation, and discuss their observational consequences and outlook.
ALTERNATIVES TO THE INFLATIONARY PARADIGM OF STRUCTURE FORMATION
Authors: BRANDENBERGER ROBERT H.
Published: July 2011

The inflationary paradigm, although very successful phenomenologically, suffers from several conceptual problems which motivate the search for alternative scenarios of early universe cosmology. Here, two possible alternatives will be reviewed. - "string gas cosmology" and the "matter bounce". Their successes and problems will be pointed out.
LARGE NON-GAUSSIANITY FROM MULTI-BRID INFLATION
Authors: NARUKO ATSUSHI , SASAKI MISAO
Published: July 2011

A model of multi-component hybrid inflation, dubbed multi-brid inflation, which may yield a large non-Gaussian paramter fNL, was proposed recently. In particular, for a two-brid inflation model with an exponential potential and the condition that the end of inflation is an ellipse in the field space, it was found that, while keeping the other observational quantities within the range consistent with observations, large non-Gaussianity is possible for certain inflationary trajectories. In this talk, in order to see if this result is a general feature of multi-brid inflation, we consider a model with a potential with an exponent quadratic in the scalar field components. We also consider a more general class of ellipses for the end of inflation. Focusing on the case of two-brid inflation, we find that large non-Gaussianity is also possible in the present model. Then by tuning the model parameters, we find that there exist models for which both the non-Gaussianity and the tensor-to-scalar ratio are large enough to be detected in the very near future.
GRAVITATIONAL-WAVE CONSTRAINTS ON ABUNDANCE OF PRIMORDIAL BLACK HOLES
Authors: SAITO RYO , YOKOYAMA JUN'ICHI
Published: July 2011

Formation of primordial black holes (PBHs) requires a large root-mean-square amplitude of density fluctuations, which generate second-order tensor perturbations that can be compared with observational constraints. We show that pulsar timing data essentially rules out PBHs with 102–4 M⊙ which were previously considered as a candidate of intermediate-mass black hoes and that PBHs with mass range 1020–25 g which provide an astrophysical candidate for dark matter may be probed by future space-based laser interferometers.