bluuebunny/crossref_metadata_2025 huggingface dataset:
A modified statistical pattern recognition approach to measuring the crosslinguistic similarity of Mandarin and English vowels
Authors: Thomson Ron I. , Nearey Terrance M. , Derwing Tracey M.
Published: September 2009

This study describes a statistical approach to measuring crosslinguistic vowel similarity and assesses its efficacy in predicting L2 learner behavior. In the first experiment, using linear discriminant analysis, relevant acoustic variables from vowel productions of L1 Mandarin and L1 English speakers were used to train a statistical pattern recognition model that simultaneously comprised both Mandarin and English vowel categories. The resulting model was then used to determine what categories novel Mandarin and English vowel productions most resembled. The extent to which novel cases were classified as members of a competing language category provided a means for assessing the crosslinguistic similarity of Mandarin and English vowels. In a second experiment, L2 English learners imitated English vowels produced by a native speaker of English. The statistically defined similarity between Mandarin and English vowels quite accurately predicted L2 learner behavior; the English vowel elicitation stimuli deemed most similar to Mandarin vowels were more likely to elicit L2 productions that were recognized as a Mandarin category; English stimuli that were less similar to Mandarin vowels were more likely to elicit L2 productions that were recognized as new or emerging categories.
Two perspectives on equipartition in diffuse elastic fields in three dimensions
Authors: Perton M. , Sánchez-Sesma F. J. , Rodríguez-Castellanos A. , Campillo M. , Weaver R. L.
Published: September 2009

The elastodynamic Green function can be retrieved from the cross correlations of the motions of a diffuse field. To extract the exact Green function, perfect diffuseness of the illuminating field is required. However, the diffuseness of a field relies on the equipartition of energy, which is usually described in terms of the distribution of wave intensity in direction and polarization. In a full three dimensional (3D) elastic space, the transverse and longitudinal waves have energy densities in fixed proportions. On the other hand, there is an alternative point of view that associates equal energies with the independent modes of vibration. These two approaches are equivalent and describe at least two ways in which equipartition occurs. The authors gather theoretical results for diffuse elastic fields in a 3D full-space and extend them to the half-space problem. In that case, the energies undergo conspicuous fluctuations as a function of depth within about one Rayleigh wavelength. The authors derive diffuse energy densities from both approaches and find they are equal. The results derived here are benchmarks, where perfect diffuseness of the illuminating field was assumed. Some practical implications for the normalization of correlations for Green function retrieval arise and they have some bearing for medium imaging.
Flow effects on the acoustic end correction of a sudden in-duct area expansion
Authors: Boij Susann
Published: September 2009

For scattering of plane waves at a sudden area expansion in a duct, the presence of flow may significantly alter the reactive properties. This paper studies the influence of a mean flow field and unstable separated flow on the reactive properties of the expansion, formulated as an end correction. Theoretical and experimental results show that the expansion end correction is significantly affected by the flow and hydrodynamic waves excited at the edge of the expansion. The effects are different in three regions where the Strouhal number is small, of order 1, and large. The influence is most significant at Strouhal numbers of the order 1, with specific limiting values for large and small Strouhal numbers, respectively. In the analytic model, an important feature is the shear layer at the edge modeled as a vortex sheet with the unsteady Kutta condition applied at the edge. The influence of Mach number, Helmholtz number, and area expansion ratio is studied, and a quasistationary, small Strouhal number, approximation yields an expression for the end correction. Further, the influence of edge condition is explored, emphasizing the importance of interaction between sound and unsteady vorticity shedding at the edge of the area expansion.
Immediate and long-term effects of hearing loss on the speech perception of children
Authors: Pittman Andrea , Vincent Kendell , Carter Leah
Published: September 2009

The purpose of the present study was to examine the immediate and long-term effects of hearing loss on the speech perception of children. Hearing loss was simulated in normally-hearing children and their performance was compared to that of children with hearing loss (long-term effects) as well as to their own performance in quiet (immediate effects). Eleven children with normal hearing (7–10 years) were matched to five children with mild to moderate sensorineural hearing loss (8–10 years). Frequency-shaped broadband noise was used to elevate the hearing thresholds of the children with normal hearing to those of their matched hearing-impaired peer. Meaningful and nonsense sentences were presented at five levels and quantified using an audibility index (AI). Comparison of the AI functions calculated for each group and listening condition revealed a significant, immediate effect of elevated hearing thresholds in the children with normal hearing but no long-term effects of hearing loss. The results of this study suggest that hearing loss affects speech perception adversely and that amplification does not fully compensate for those effects. However, the data suggest that over the long term children may develop compensatory strategies to reduce the effects of hearing loss.
An influence of amplitude modulation on interaural level difference processing suggested by learning patterns of human adults
Authors: Zhang Yuxuan , Wright Beverly A.
Published: September 2009

Humans rely on interaural level differences (ILDs) to determine the location of sound sources, particularly for high-frequency sounds. Previously, ILD-discrimination performance with a 4-kHz pure tone was reported to improve with multi-hour training. Here the effect of the same training regimen on ILD discrimination with a 4-kHz tone sinusoidally amplitude modulated (SAM) at 0.3 kHz was examined. Ten of the 16 trained listeners improved more than untrained controls, demonstrating training-induced learning. However, compared to the learning previously obtained with the 4-kHz pure tone, learning with the SAM tone was less predictable based on starting performance, took longer to complete, and was characterized by specificity to stimulus type (SAM vs pure tones) rather than stimulus frequency. These differences demonstrate an influence of amplitude modulation on learning of ILD discrimination. This influence suggests that the auditory system makes use of amplitude envelope information in determining ILD-discrimination performance, a form of interaction between time and level processing in the binaural system.
Pitch bending and glissandi on the clarinet: Roles of the vocal tract and partial tone hole closure
Authors: Chen Jer-Ming , Smith John , Wolfe Joe
Published: September 2009

Clarinettists combine non-standard fingerings with particular vocal tract configurations to achieve pitch bending, i.e., sounding pitches that can deviate substantially from those of standard fingerings. Impedance spectra were measured in the mouth of expert clarinettists while they played normally and during pitch bending, using a measurement head incorporated within a functioning clarinet mouthpiece. These were compared with the input impedance spectra of the clarinet for the fingerings used. Partially uncovering a tone hole by sliding a finger raises the frequency of clarinet impedance peaks, thereby allowing smooth increases in sounding pitch over some of the range. To bend notes in the second register and higher, however, clarinettists produce vocal tract resonances whose impedance maxima have magnitudes comparable with those of the bore resonance, which then may influence or determine the sounding frequency. It is much easier to bend notes down than up because of the phase relations of the bore and tract resonances, and the compliance of the reed. Expert clarinettists performed the glissando opening of Gershwin’s Rhapsody in Blue. Here, players coordinate the two effects: They slide their fingers gradually over open tone holes, while simultaneously adjusting a strong vocal tract resonance to the desired pitch.
High resolution population density imaging of random scatterers with the matched filtered scattered field variance
Authors: Andrews Mark , Gong Zheng , Ratilal Purnima
Published: September 2009

The matched filter enables imaging with high spatial resolution and high signal-to-noise ratio by coherent correlation with the expected field from what is assumed to be a discrete scatterer. In many physical imaging systems, however, returns from a large number of randomized scatterers, ranging from thousands to millions of individuals, are received together and the coherent or expected field vanishes. Despite this, it is shown that cross-spectral coherence in the matched filtered variance retains a pulse compression property that enables high-resolution imaging of scatterer population density. Analytic expressions for the statistical moments of the broadband matched filtered scattered field are derived in terms of the medium’s Green’s function, object scatter function, and spatial distribution using a single-scatter approximation. The formulation can account for potential dispersion in the medium and target over the signal bandwidth, and can be used to compare the relative levels of the coherent and incoherent scattered intensities. The analytic model is applied to investigate population density imaging of fish distributions in the Gulf of Maine with an ultrasonic echosounder. The results are verified with numerical Monte-Carlo simulations that include multiple scattering, illustrating that the single-scatter approximation is valid even for relatively dense Atlantic herring (Clupea harengus) schools.
Bottlenose dolphins (Tursiops truncatus) moan as low in frequency as baleen whales
Authors: van der Woude Sylvia E.
Published: September 2009

Despite a vast number of investigations on the vocal repertoire of bottlenose dolphins, it is still not fully described. This publication reports on a newly discovered tonal low-frequency vocalization in the species at frequencies similar to baleen whale “moans.” Dolphin moans are characterized by a slightly modulated fundamental frequency well below 500 Hz that ranges in duration from 0.2 to 8.7 s. Recordings (68 h) were obtained from eight Black Sea bottlenose dolphins residing in an open sea enclosure in Israel. Of 132 unambiguous moans, 49 occurred clearly associated with the release of air from a dolphin’s blowhole, which allowed for identifying five moaning individuals. Reasons why this vocalization has not been previously described in any toothed whale are discussed. Moans might not be part of the species’ natural repertoire but likewise might have been overlooked due to their inconspicuousness and scarcity, technical limitations, or methodological biases. The function of moaning is unclear; however, the data suggest that moans are signals of anticipating physical satiation provided by humans, i.e., feeding or petting. To further address these questions, verification of moans in other populations and experimental investigation of the properties of moan production and perception are required.
Comparison of directional selectivity of hearing in a beluga whale and a bottlenose dolphin
Authors: Popov Vladimir V. , Supin Alexander Ya.
Published: September 2009

Hearing thresholds as a function of sound-source azimuth were measured in a beluga whale Delphinapterus leucas and a bottlenose dolphin Tursiops truncatus in identical conditions using the auditory evoked-potential method. In both the beluga whale and bottlenose dolphin, the receiving beam width narrowed with frequency increase. At all frequencies, the receiving beam was markedly wider in the beluga whale than in the bottlenose dolphin. In particular, the 3-dB beam width in the beluga whale narrowed from ±33.5° at 8 kHz frequency to ±14.3° at 128 kHz; the 6-dB beam width narrowed from ±56.9° to ±18.9°, respectively. In the bottlenose dolphin, the 3-dB beam width decreased from ±19.9° at 8 kHz to ±6.3° at 128 kHz; the 6-dB beam width decreased from ±33.1° to ±8.4°, respectively. In the bottlenose dolphin, the axis of the low-frequency receiving beam deviated from the midline up to 15°; in the beluga whale, this effect was not detected. The audiograms of both the beluga whale and bottlenose dolphin were azimuth-dependent: from an audiogram featuring the best sensitivity at intermediate frequencies at 0° to that featuring monotonous threshold increase with frequency increase at 90°. In the beluga whale, this dependence was less prominent than in the bottlenose dolphin.
Acoustic markers of sarcasm in Cantonese and English
Authors: Cheang Henry S. , Pell Marc D.
Published: September 2009

The goal of this study was to identify acoustic parameters associated with the expression of sarcasm by Cantonese speakers, and to compare the observed features to similar data on English [Cheang, H. S. and Pell, M. D. (2008). Speech Commun. 50, 366–381]. Six native Cantonese speakers produced utterances to express sarcasm, humorous irony, sincerity, and neutrality. Each utterance was analyzed to determine the mean fundamental frequency (F0), F0-range, mean amplitude, amplitude-range, speech rate, and harmonics-to-noise ratio (HNR) (to probe voice quality changes). Results showed that sarcastic utterances in Cantonese were produced with an elevated mean F0, and reductions in amplitude- and F0-range, which differentiated them most from sincere utterances. Sarcasm was also spoken with a slower speech rate and a higher HNR (i.e., less vocal noise) than the other attitudes in certain linguistic contexts. Direct Cantonese-English comparisons revealed one major distinction in the acoustic pattern for communicating sarcasm across the two languages: Cantonese speakers raised mean F0 to mark sarcasm, whereas English speakers lowered mean F0 in this context. These findings emphasize that prosody is instrumental for marking non-literal intentions in speech such as sarcasm in Cantonese as well as in other languages. However, the specific acoustic conventions for communicating sarcasm seem to vary among languages.
The contrast-source stress-velocity integral-equation formulation of three-dimensional time-domain elastodynamic scattering problems: A structured approach using tensor partitioning
Authors: de Hoop Adrianus T. , Abubakar Aria , Habashy Tarek M.
Published: September 2009

The contrast-source stress-velocity integral-equation formulation of three-dimensional time-domain elastodynamic scattering problems is discussed. A novel feature of the formulation is a tensor partitioning of the relevant dynamic stress and the contrast source volume density of deformation rate. The partitioning highlights several features about the structure of the formulation. These can advantageously be incorporated in a computational implementation of the method. An application to the case of a scatterer composed of isotropic material and embedded in an isotropic elastic background medium shows that the corresponding newly introduced constitutive coefficients are more natural as a characterization of the media than the traditional Lamé coefficients.
Role of mask pattern in intelligibility of ideal binary-masked noisy speech
Authors: Kjems Ulrik , Boldt Jesper B. , Pedersen Michael S. , Lunner Thomas , Wang DeLiang
Published: September 2009

Intelligibility of ideal binary masked noisy speech was measured on a group of normal hearing individuals across mixture signal to noise ratio (SNR) levels, masker types, and local criteria for forming the binary mask. The binary mask is computed from time-frequency decompositions of target and masker signals using two different schemes: an ideal binary mask computed by thresholding the local SNR within time-frequency units and a target binary mask computed by comparing the local target energy against the long-term average speech spectrum. By depicting intelligibility scores as a function of the difference between mixture SNR and local SNR threshold, alignment of the performance curves is obtained for a large range of mixture SNR levels. Large intelligibility benefits are obtained for both sparse and dense binary masks. When an ideal mask is dense with many ones, the effect of changing mixture SNR level while fixing the mask is significant, whereas for more sparse masks the effect is small or insignificant.
Tuning properties of the auditory frequency-shift detectors
Authors: Demany Laurent , Pressnitzer Daniel , Semal Catherine
Published: September 2009

Demany and Ramos [(2005). J. Acoust. Soc. Am. 117, 833–841] found that it is possible to hear an upward or downward pitch change between two successive pure tones differing in frequency even when the first tone is informationally masked by other tones, preventing a conscious perception of its pitch. This provides evidence for the existence of automatic frequency-shift detectors (FSDs) in the auditory system. The present study was intended to estimate the magnitude of the frequency shifts optimally detected by the FSDs. Listeners were presented with sound sequences consisting of (1) a 300-ms or 100-ms random “chord” of synchronous pure tones, separated by constant intervals of either 650 cents or 1000 cents; (2) an interstimulus interval (ISI) varying from 100 to 900 ms; (3) a single pure tone at a variable frequency distance (Δ) from a randomly selected component of the chord. The task was to indicate if the final pure tone was higher or lower than the nearest component of the chord. Irrespective of the chord’s properties and of the ISI, performance was best when Δ was equal to about 120 cents (1/10 octave). Therefore, this interval seems to be the frequency shift optimally detected by the FSDs.
Pitch discrimination by ferrets for simple and complex sounds
Authors: Walker Kerry M. M. , Schnupp Jan W. H. , Hart-Schnupp Sheelah M. B. , King Andrew J. , Bizley Jennifer K.
Published: September 2009

Although many studies have examined the performance of animals in detecting a frequency change in a sequence of tones, few have measured animals’ discrimination of the fundamental frequency (F0) of complex, naturalistic stimuli. Additionally, it is not yet clear if animals perceive the pitch of complex sounds along a continuous, low-to-high scale. Here, four ferrets (Mustela putorius) were trained on a two-alternative forced choice task to discriminate sounds that were higher or lower in F0 than a reference sound using pure tones and artificial vowels as stimuli. Average Weber fractions for ferrets on this task varied from ∼20% to 80% across references (200–1200 Hz), and these fractions were similar for pure tones and vowels. These thresholds are approximately ten times higher than those typically reported for other mammals on frequency change detection tasks that use go/no-go designs. Naive human listeners outperformed ferrets on the present task, but they showed similar effects of stimulus type and reference F0. These results suggest that while non-human animals can be trained to label complex sounds as high or low in pitch, this task may be much more difficult for animals than simply detecting a frequency change.
A cross-dialect acoustic description of vowels: Brazilian and European Portuguese
Authors: Escudero Paola , Boersma Paul , Rauber Andréia Schurt , Bion Ricardo A. H.
Published: September 2009

This paper examines four acoustic correlates of vowel identity in Brazilian Portuguese (BP) and European Portuguese (EP): first formant (F1), second formant (F2), duration, and fundamental frequency (F0). Both varieties of Portuguese display some cross-linguistically common phenomena: vowel-intrinsic duration, vowel-intrinsic pitch, gender-dependent size of the vowel space, gender-dependent duration, and a skewed symmetry in F1 between front and back vowels. Also, the average difference between the vocal tract sizes associated with ∕i∕ and ∕u∕, as measured from formant analyses, is comparable to the average difference between male and female vocal tract sizes. A language-specific phenomenon is that in both varieties of Portuguese the vowel-intrinsic duration effect is larger than in many other languages. Differences between BP and EP are found in duration (BP has longer stressed vowels than EP), in F1 (the lower-mid front vowel approaches its higher-mid counterpart more closely in EP than in BP), and in the size of the intrinsic pitch effect (larger for BP than for EP).
Theoretical limitations of the elastic wave equation inversion for tissue elastography
Authors: Baghani Ali , Salcudean Septimiu , Rohling Robert
Published: September 2009

This article examines the theoretical limitations of the local inversion techniques for the measurement of the tissue elasticity. Most of these techniques are based on the estimation of the phase speed or the algebraic inversion of a one-dimensional wave equation. To analyze these techniques, the wave equation in an elastic continuum is revisited. It is proven that in an infinite medium, harmonic shear waves can travel at any phase speed greater than the classically known shear wave speed, μ∕ρ, by demonstrating this for a special case with cylindrical symmetry. Hence in addition to the mechanical properties of the tissue, the phase speed depends on the geometry of the wave as well. The elastic waves in an infinite cylindrical rod are studied. It is proven that multiple phase speeds can coexist for a harmonic wave at a single frequency. This shows that the phase speed depends not only on the mechanical properties of the tissue but also on its shape. The final conclusion is that the only way to avoid theoretical artifacts in the elastograms obtained by the local inversion techniques is to use the shear wave equation as expressed in the curl of the displacements, i.e., the rotations, for the inversion.
Acoustic simulations of Mudejar-Gothic churches
Authors: Galindo Miguel , Zamarreño Teófilo , Girón Sara
Published: September 2009

In this paper, an iterative process is used in order to estimate the values of absorption coefficients of those materials of which little is known in the literature, so that an acoustic simulation can be carried out in Mudejar-Gothic churches. The estimation of the scattering coefficients, which is even less developed, is based on the size of the irregularities. This methodology implemented is applied to six Mudejar-Gothic churches of Seville (southern Spain). The simulated monophonic acoustic parameters, both in the frequency domain and as a function of source-receiver distance (spatial distribution), are analyzed and compared with the in situ measures. Good agreement has been found between these sets of values, whereby each parameter is discussed in terms of the just noticeable difference. This procedure for existing buildings, especially for those which are rich in heritage, enables a reliable evaluation of the effect on the maintenance, restoration, and conditioning for new uses, as well as the recreation of the acoustic environment of ancient times. Along these lines, the acoustic influence of the timber roof and the presence of the public in these churches have also been studied.
Coupling of axial and transverse displacement fields in a straight beam due to boundary conditions
Authors: Ginsberg Jerry H.
Published: September 2009

A classical simply-supported beam is modified by tilting the pad constraining the roller. The consequence is that the axial and transverse displacements of the beam are coupled by the boundary conditions. The eigenanalysis methodology is extended to this unusual situation where displacement components are coupled, even though each displacement has a different associated wavenumber. The dependence of the natural frequencies on the tilt angle is evaluated and typical results for the eigenfunctions are presented. The response of the beam to harmonic point force excitation is synthesized by constructing a modal series. Frequency response functions at the drive point for cases where the force is applied in the axial and transverse directions are computed. The results indicate that deviations of the tilt angle from zero affect the displacement in the direction that is orthogonal to the excitation much more than the driven displacement.
Leakage effect in Helmholtz resonators
Authors: Selamet Ahmet , Kim Hyunsu , Huff Norman T.
Published: September 2009

The effect of leakage in Helmholtz resonators has been investigated in this predominantly experimental study combined with a computational effort. A prototype has been built with varying levels of intentional leakage due to holes in the baffle and gaps between the baffle and the housing. The transmission loss is then measured with different combinations of holes and/or gaps. Such openings, even though their cross-sectional areas are small, are found to have a significant impact on transmission loss. The effect of holes versus gaps is also compared as a function of the leakage area. The present study illustrates the critical need to account for such leakages at the design stage for the proper tuning of these resonators.
The variance of the discrete frequency transmission function of a reverberant room
Authors: Davy John L.
Published: September 2009

This paper first shows experimentally that the distribution of modal spacings in a reverberation room is well modeled by the Rayleigh or Wigner distribution. Since the Rayleigh or Wigner distribution is a good approximation to the Gaussian orthogonal ensemble (GOE) distribution, this paper confirms the current wisdom that the GOE distribution is a good model for the distribution of modal spacings. Next this paper gives the technical arguments that the author used successfully to support the pragmatic arguments of Baade and the Air-conditioning and Refrigeration Institute of USA for retention of the pure tone qualification procedure and to modify a constant in the International Standard ISO 3741:1999(E) for measurement of sound power in a reverberation room.
Pulse-echo interaction in free-flying horseshoe bats, Rhinolophus ferrumequinum nippon
Authors: Shiori Yu , Hiryu Shizuko , Watanabe Yu , Riquimaroux Hiroshi , Watanabe Yoshiaki
Published: September 2009

Because horseshoe bats emit a long-duration pulse, the returning echo temporally overlaps with the emitted pulse during echolocation. Here, the pulse-echo interaction that horseshoe bats actually experience during flight was examined using onboard telemetry sound recordings. Doppler-shifted returning echoes produced beats in the amplitude patterns of constant-frequency components. Bats shortened the pulse duration with target distance, but the overlap duration was at least 8 ms within the approach phase. The computations suggest that the phase difference in slowly amplitude-modulated sound (the beat signal) provides a useful cue for target localization.
Estimation of cochlear response times using lateralization of frequency-mismatched tones
Authors: Strelcyk Olaf , Dau Torsten
Published: September 2009

Behavioral and objective estimates of cochlear response times (CRTs) and traveling-wave (TW) velocity were compared for three normal-hearing listeners. Differences between frequency-specific CRTs were estimated via lateralization of pulsed tones that were interaurally mismatched in frequency, similar to a paradigm proposed by Zerlin [(1969). J. Acoust. Soc. Am. 46, 1011–1015]. In addition, derived-band auditory brainstem responses were obtained as a function of derived-band center frequency. The latencies extracted from these responses served as objective estimates of CRTs. Estimates of TW velocity were calculated from the obtained CRTs. The correspondence between behavioral and objective estimates of CRT and TW velocity was examined. For frequencies up to 1.5 kHz, the behavioral method yielded reproducible results, which were consistent with the objective estimates. For higher frequencies, CRT differences could not be estimated with the behavioral method due to limitations of the lateralization paradigm. The method might be useful for studying the spatiotemporal cochlear response pattern in human listeners.
Iterated rippled noise discrimination at long durations
Authors: Yost William A.
Published: September 2009

Iterated rippled noise (IRN) was used to study discrimination of IRN stimuli with a lower number of iterations from IRN stimuli with a higher number of iterations as a function of stimulus duration (100–2000 ms). Such IRN stimuli differ in the strength of the repetition pitch. In some cases, the gain used to generate IRN stimuli was adjusted so that both IRN stimuli in the discrimination task had the same height of the first peak in the autocorrelation function or autocorrelogram. In previous work involving short-duration IRN stimuli (<500 ms), listeners were not able to discriminate between IRN stimuli that had different numbers of iterations but the same height of the first peak in the autocorrelation function. In the current study, IRN discrimination performance improved with increases in duration, even in cases when the height of the first peak in the autocorrelation was the same for the two IRN stimuli. Thus, future studies involving discrimination of IRN stimuli may need to use longer durations (1 s or greater) than those that have been used in the past.
Identifying acoustical coupling by measurements and prediction-models for St. Peter’s Basilica in Rome
Authors: Martellotta Francesco
Published: September 2009

St. Peter’s Basilica is one of the largest buildings in the world, having a huge volume resulting from the addition of different parts. Consequently, sound propagation cannot be interpreted using a conventional approach and requires experimental measures to be compared with statistical-acoustics and geometrical predictions in order to explain the interplay between shape, materials, and sound waves better. In previous research one of the most evident effects, the surprisingly low reverberation time, was believed to result from acoustical coupling phenomena. Taking advantage of more refined measuring techniques available today an acoustic survey was carried out and the results were analyzed using different methods, including Bayesian parameter estimation of multiple slope decays and directional energy plots, which showed that coupling effects actually take place, even though measured reverberation times were longer than those given in previous studies. In addition, experimental results were compared with geometrical- and statistical-acoustic models of the basilica, which showed that careful selection of input data and, in statistical models, the inclusion of phenomena such as direct sound radiation and non-diffuse energy transfer, allow obtaining accurate results. Finally, both models demonstrated that reduced reverberation depends more on increased absorption of decorated surfaces than on coupling effects.
Temporal weighting in loudness of broadband and narrowband signals
Authors: Rennies Jan , Verhey Jesko L.
Published: September 2009

Temporal weights used by listeners when judging the overall loudness of a stimulus were measured for a 1-s-long noise centered around 2kHz, whose level was randomly perturbed every 100ms. The bandwidth was either 6400Hz (broadband condition) or 400Hz (narrowband condition). The first 100ms contributed significantly more than later segments to overall loudness perception in the broadband condition. The effect was significantly reduced in the narrowband condition which is in line with the hypothesis that a greater spectral loudness summation at stimulus onset might be the mechanism behind the onset accentuation.
Acoustic and spectral patterns in young children’s stop consonant productions
Authors: Nissen Shawn L. , Fox Robert Allen
Published: September 2009

The aim of this study was to examine the acoustic and spectral patterns of stop articulation in the speech of pre-pubescent children. A set of voiceless stop consonants, /ptk/, produced by a group of adults and typically developing children 3–5years of age were examined in terms of multiple acoustic and spectral parameters. Findings indicated that, with the exception of spectral kurtosis, the acoustic and spectral characteristics of the stop productions varied significantly as a function of place of articulation and vowel context. Sex-specific differences in spectral slope, mean, and skewness were found for the 5-year-old and adult speakers. Such differences in adult speakers can be explained in part by variation in vocal tract size across the sex of the speaker; however, vocal tract dimorphism is typically not present in pre-pubescent children. Thus, the findings of this study provide some support that sex-specific differences in the speech patterns of young children may be associated with learned or behavioral factors, such as patterns of obstruent articulation that depend in part on a culturally determined male-female archetype.
Reconstruction of Molecular Orbital Densities from Photoemission Data
Authors: Puschnig Peter , Berkebile Stephen , Fleming Alexander J. , Koller Georg , Emtsev Konstantin , Seyller Thomas , Riley John D. , Ambrosch-Draxl Claudia , Netzer Falko P. , Ramsey Michael G.
Published: September 2009

Electron Comings and Goings

Advances in computational chemistry have enabled remarkably detailed calculations of electrons' spatial arrangements in complex molecules. Experimental confirmation of these orbital geometries remains challenging, however, particularly for molecules bound in thin layers to underlying surfaces—a morphology of increasing interest in organic semiconductor development.

Puschnig
et al.

(p.
702
, published online 10 September) mapped the trajectories of photoelectrons emitted from polycyclic aromatic molecules deposited on copper and extracted spatial profiles of the orbitals from which these electrons emerged. The method of analysis takes advantage of the straightforward Fourier relation between position and momentum and complements orbital imaging techniques based on scanning tunneling microscopy.
Repetitive Readout of a Single Electronic Spin via Quantum Logic with Nuclear Spin Ancillae
Authors: Jiang L. , Hodges J. S. , Maze J. R. , Maurer P. , Taylor J. M. , Cory D. G. , Hemmer P. R. , Walsworth R. L. , Yacoby A. , Zibrov A. S. , Lukin M. D.
Published: September 2009

Extending Quantum Memory

Quantum information processing and communication relies on the ability to store, retrieve, and manipulate information stored in quantum memories. In most practical instances, however, the stored quantum information is fragile and susceptible to loss during readout.

Jiang
et al.

(p.
267
, published online 10 September) used a combination of quantum logic operations on the electronic spin of a nitrogen vacancy center in diamond to control its interactions with a nearby set of proximal nuclear spins of the carbon network. In this setup, the quantum memory of the electron spin could be made more robust. Extending the lifetime and allowing multiple readouts of the quantum memory should prove a useful technique for quantum information processing.
Using Neural Measures of Economic Value to Solve the Public Goods Free-Rider Problem
Authors: Krajbich Ian , Camerer Colin , Ledyard John , Rangel Antonio
Published: September 2009

Observing Unrevealed Preferences

Ideally, it would be possible to design a system of incentives for the production and allocation of public goods with the following properties: (i) it would be budget-balanced; (ii) people would participate willingly because they would not be made worse off by doing so; (iii) it would be easy for each participant to find his or her optimal strategy; and (iv) the equilibrium solution would yield the optimal production of the public good. Sadly, this set of conditions cannot be satisfied simultaneously because it requires that self-interested individuals reveal voluntarily and truthfully how much they value the public good.

Krajbich
et al.

(p.
596
, published online 10 September) ask whether a neuroimaging measurement can be used to circumvent this reliance on observed behavior by decoding individual valuations. A decoding accuracy of 55% would be sufficient, and, in a laboratory experiment, an optimal provision of public goods was indeed achieved.
The role of wind in determining the timing of the spring bloom in the Strait of Georgia
Authors: Collins A. Kathleen , Allen Susan E. , Pawlowicz Rich
Published: September 2009

A coupled biophysical model of the Strait of Georgia (SoG), British Columbia, Canada, has been developed and successfully predicts the timing of the spring phytoplankton bloom. The physical model is a one-dimensional vertical mixing model, using a K-profile parametrization of the boundary layer, forced with high frequency meteorological data. The biological model includes one phytoplankton class (microphytoplankton) and one nutrient source (nitrate). The spring bloom in the SoG occurs when phytoplankton receive enough light that their growth rates exceed their loss rates. The amount of light that the phytoplankton receive is a function of solar radiation and the depth of mixing. The model was used to determine what physical factors are controlling the phytoplankton losses and the light received by the phytoplankton. Wind was found to control the spring bloom arrival time, with strong winds increasing the mixing-layer depth and delaying the bloom. The amount of incoming solar irradiance, through amount of cloud cover, had a secondary effect. The freshwater input (primarily Fraser River discharge) had an insignificant effect on the timing. Increased freshwater flux increases the buoyancy flux and thus decreases the mixing-layer depth but also increases the strength of the estuarine circulation, increasing the advective loss.
Polyploid microsatellite data reveal stock complexity among estuarine North American green sturgeon (Acipenser medirostris)
Authors: Israel Joshua A. , Bando K. Jun , Anderson Eric C. , May Bernie
Published: September 2009

North American green sturgeon ( Acipenser medirostris ) display the distinctive behavior of long ocean migrations along the west coast punctuated by summer residence in estuaries; however, little is known about stock composition in these tidal environments. Pairwise comparisons and genetic clustering analysis were used to characterize the two green sturgeon Distinct Population Segments (DPSs) from 20 collections using eight tetrasomic and two disomic microsatellite loci. The observed pattern of green sturgeon DPS composition among five estuaries in California, Oregon, and Washington was supported with assignment testing approaches utilizing the same genotypic data in codominant polysomic and pseudodominant allele phenotype formats. The majority of individuals in northern DPS estuaries originated from the threatened Southern DPS, except in Winchester Bay and Grays Harbor. We detected few Northern DPS green sturgeon in San Pablo Bay, the principal Southern DPS estuary, supporting that green sturgeon preferentially disperse north once they enter their coastal migration. Our genetic findings suggest that stock complexity in green sturgeon is pervasive and support precautionary, interjurisdictional approaches for managing green sturgeon beyond rigid, regulatory boundaries.
Patterns of genetic differentiation between two co-occurring demersal species: the red mullet (Mullus barbatus) and the striped red mullet (Mullus surmuletus)
Authors: Galarza J. A. , Turner G. F. , Macpherson E. , Rico C.
Published: September 2009

The accurate identification of genetic partitioning is of primarily importance when devising conservation management strategies for today’s marine resources. The great variety of genetic structure displayed by demersal species underscores the need for the identification of common patterns that can be found across species. Here, we analyse allele frequency variation at 10 microsatellite loci of two congener demersal fish, the red mullet ( Mullus barbatus ) and the striped red mullet ( Mullus surmuletus ), from the Atlantic Ocean and the Mediterranean Sea. The results indicate that two different gene flow patterns exist between these species. The red mullet’s genetic distribution was found to be highly structured, resembling that of a metapopulation composed by independent, self-recruiting subpopulations with some connections between them. The striped red mullet displayed less genetic heterogeneity within the Mediterranean Sea and a substantial gene flow reduction between the Atlantic Ocean and Mediterranean Sea. Our results indicate that gene flow patterns in the demersal environment can be substantially different between closely related species with highly comparable biology, suggesting that biogeographic boundaries can affect demersal species in a different way despite common ecological features and spatial overlap. We conclude that the delimitation of such boundaries could be determined by the fine differences in life history traits between species.
In situ dissolved organic carbon (DOC) release by submerged macrophyte–epiphyte communities in southern Quebec lakes
Authors: Demarty M. , Prairie Y. T.
Published: September 2009

We studied the in situ release of dissolved organic carbon (DOC) by growing a submerged freshwater macrophyte–epiphyte complex. Incubations with benthic chambers in five southeastern Quebec lakes show a net DOC production for different communities of Myriophyllum spicatum and Potamogeton spp. Daytime DOC release rates range from undetectable to 9.7 mg C·m–2·h–1. Although DOC release was restricted to daylight hours and thus suggestive of a photosynthesis-related process, we found no strong link between DOC release rates and concurrent illumination or temperature. We found no difference in DOC release rates between the three main colonizing species of the studied region. The overall mean DOC release rate was 4.57 mg C·m–2·h–1(standard deviation (SD), ±0.65) or 56 µg C·g dry weight–1·h–1(SD, ±8), which we suggest can be used for extrapolations at the lake scale.
A Bayesian mark–recapture model for multiple-recapture data in a catch-and-release fishery
Authors: Whitlock Rebecca , McAllister Murdoch
Published: September 2009

This paper extends a state–space Bayesian mark–recapture framework to multiple-recapture data to estimate fishery-specific capture and mortality rates and seasonal movement rates for fish in different length classes. The methodology is applied to tag recapture data for white sturgeon ( Acipenser transmontanus ) collected in the recreational fishery and the Canadian Department of Fisheries and Ocean’s test fishery at Albion in the lower Fraser River. Significant differences were found between some estimated movement rates by season and length class, supporting the notion of there being marked differences in seasonal movement patterns between different life history stages of A. transmontanus in the lower Fraser River. Uncertainty in the tag reporting rate parameter, quantified using a recreational creel sampling program, is summarized by a prior distribution. The utility of recreational fishing effort as a model covariate in accounting for seasonal and spatial variation in recapture rates is addressed using Bayesian model evaluation criteria. The data provide strong support in favour of models that include fishing effort as a covariate. The appropriate level of stratification for the recreational catchability parameter q is assessed using Bayesian model evaluation criteria; models in which q is estimated by season and length class have the highest posterior probabilities.
Mechanisms regulating oocyte recruitment and skipped spawning in Northeast Arctic cod (Gadus morhua)
Authors: Skjæraasen Jon Egil , Kennedy James , Thorsen Anders , Fonn Merete , Strand Bente Njøs , Mayer Ian , Kjesbu Olav Sigurd
Published: September 2009

To examine mechanisms that affect fecundity, atresia, and skipped spawning in Northeast Arctic cod ( Gadus morhua ), we conducted an experiment where wild-caught cod (>60 cm) kept under restricted food regimes were subjected to monthly biopsies and hormonal and physical measurements. The power of body weight as a fecundity proxy increased until the presumed end of follicle proliferation in early November; thereafter, it remained stable. Atresia occurred in most females, but for maturing females, mainly close to spawning. Eighteen percent of the females had small gonads with predominantly previtellogenic oocytes at sacrifice in January. These females were past-spawners, verified by postovulatory follicles in their gonads. These “skippers” had lower condition than maturing cod from December, smaller livers upon sacrifice, and lower plasma 17β-estradiol values from early November. Until November, oocytes developed similarly for all females, but in November, oocyte development was arrested at the early cortical alveoli stage and atresia occurred in all skippers. In summary, fecundity and skipped spawning seem highly influenced by energy reserves during early vitellogenesis and was limited to females only. Finally, skippers were identifiable long before the predicted onset of spawning, which could have implications for forecasting of egg production and hence stock–recruitment relationships.
Isotope shifts in the [10.1]4–X4 (0–0) and [10.5]3–X4 (0–0) transitions of NdOThis article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.
Authors: Bernard Alain , Ross Amanda J.
Published: September 2009

High-resolution Fourier transform thermal emission spectra of NdO (natural isotopic composition) have been recorded in the near infrared. Rotational analyses of the 0–0 band of the [10.132]4–X(1)4 system have been performed for all seven isotopomers, and the 0–0 band of the [10.506]3–X(1)4 system has been analysed for 142NdO, 144NdO, and 146NdO. Experimental data have been merged into a global fit to obtain a unique set of isotopically consistent rotational spectroscopic constants, scaled to 142NdO by assuming isotopic relationships within the Born–Oppenheimer approximation, but with independent band origins. These vibronic energy shifts reflect the isotopic shifts observed in some atomic lines also seen in the spectrum. A catalogue of experimental line positions and o−c values is available as Supplementary data.
Fourier transform microwave spectrum of and Born–Oppenheimer breakdown effects in tungsten monoxide, WOThis article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.Dedicated to Ronald M. Lees and Colan Linton, in recognition of their outstanding contributions to science.
Authors: Krumrey Christine , Cooke Stephen A. , Russell Douglas K. , Gerry Michael C.L.
Published: September 2009

Rotational transitions of eight isotopomers of tungsten monoxide, WO, in its X0+ ground electronic state, have been measured in the frequency range 22–26 GHz, using a cavity Fourier transform microwave spectrometer. The samples were prepared by laser ablation of W metal in the presence of O2 and stabilized in pulsed supersonic jets of Ne or Ar. Only the J = 1–0 transition was accessible within the frequency range of the spectrometer. It was measured for the ground (v = 0) and two excited (v = 1, 2) vibrational states. Hyperfine structure due to 183W nuclear spin-rotation coupling was found for 183WO. The overall spectral fit used a Dunham-type expression including Born–Oppenheimer breakdown parameters. Only the v = 0 and 1 states could be fit to the measurement accuracy because of a small perturbation of the v = 2 state. It was necessary to account for the finite nuclear size of the W nucleus in the fit. The resulting parameter V 01W agreed well with a value calculated using density functional theory. Equilibrium internuclear distances re have been evaluated.