bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of a STEM Intervention on Elementary Students' Science Knowledge and Skills
Authors: Cotabish Alicia , Dailey Debbie , Robinson Ann , Hughes Gail
Published: May 2013

The purpose of the study was to assess elementary students' science process skills, content knowledge, and concept knowledge after one year of participation in an elementary Science, Technology, Engineering, and Mathematics (STEM) program. This study documented the effects of the combination of intensive professional development and the use of inquiry‐based science instruction in the elementary classroom, including the benefits of using rigorous science curriculum with general education students. The results of the study revealed a statistically significant gain in science process skills, science concepts, and science‐content knowledge by general education students in the experimental group when compared with students in the comparison group. Moreover, teacher participation in the STEM program had a statistically significant impact on students' variability in posttest scores. These interim student performance data support the implementation of rigorous differentiated science curriculum focused on improving science concept, content knowledge, and process skills.
Evaluating the impact of pre‐transplant desensitization utilizing a plasmapheresis and low‐dose intravenous immunoglobulin protocol on BK viremia in renal transplant recipients
Authors: Gabardi S. , Townsend K. , Martin S.T. , Chandraker A.
Published: May 2013

Background

A correlation exists between polyomavirus BK (BKV) viremia in renal transplant recipients (RTR) and the degree of immunosuppression. However, the impact of pre‐transplant desensitization on the incidence of BKV viremia is unknown.

Methods

This retrospective study evaluated living‐donor RTR between January 2004 and December 2008 receiving routine BKV viral load monitoring. Patients were divided into those who underwent pre‐transplant desensitization (n = 20) and those who did not (n = 71). The primary endpoint was the incidence of BKV viremia at 1 year post transplant.

Results

All demographic data were similar, except for more female patients (65% vs. 36.6%; P = 0.0392) in the desensitized group. More desensitized patients had a previous transplant (75% vs. 12.7%; P < 0.0001) and were more likely to be induced with basiliximab (75% vs. 35.2%; P = 0.0021). Following transplantation, antibody‐mediated rejection (AMR) rates were highest in the desensitized group (55% vs. 1.4%; P < 0.0001). The incidence of BKV viremia at 1 year post transplant was significantly higher in desensitized patients (45% vs. 19.7%; P = 0.0385). Desensitization was also associated with a higher prevalence of BKV viremia at any time post transplant (50% vs. 22.5%; P = 0.0245), polyomavirus‐associated nephropathy (20% vs. 2.8%; P = 0.0198) and BKV‐related allograft loss (10% vs. 0%; P = 0.0464). Also of note, in a subgroup analysis of only our desensitized patients, it did not appear that development of AMR significantly impacted the incidence of BKV viremia in these individuals.

Conclusions

This analysis reveals that pre‐transplant desensitization significantly increases the risk for BKV viremia and nephropathy.
COP1 re‐accumulates in the nucleus under shade
Authors: Pacín Manuel , Legris Martina , Casal Jorge J.
Published: May 2013

Shade‐avoider plants typically respond to shade‐light signals by increasing the rate of stem growth. CONSTITTUTIVE PHOTOMORPHOGENESIS 1 (COP1) is an E3 ligase involved in the ubiquitin labelling of proteins targeted for degradation. In dark‐grown seedlings, COP1 accumulates in the nucleus and light exposure causes COP1 migration to the cytosol. Here, we show that in Arabidopsis thaliana, COP1 accumulates in the nucleus under natural or simulated shade, despite the presence of far‐red light. In plants grown under white light, the transfer to shade‐light conditions triggers an unexpectedly rapid re‐accumulation of COP1 in the nucleus. The partial simulation of shade by lowering either blue or red light levels (maintaining far‐red light) caused COP1 nuclear re‐accumulation. Hypocotyl growth of wild‐type seedlings is more sensitive to afternoon shade than to morning shade. A residual response to shade was observed in the cop1 mutant background, but these seedlings showed inverted sensitivity as they responded to morning shade and not to afternoon shade. COP1 overexpression exaggerated the wild‐type pattern by enhancing afternoon sensitivity and making morning shade inhibitory of growth. COP1 nuclear re‐accumulation also responded more strongly to afternoon shade than to morning shade. These results are consistent with a signalling role of COP1 in shade avoidance. We propose a function of COP1 in setting the daily patterns of sensitivity to shade in the fluctuating light environments of plant canopies.
Downregulation of multiple CDK inhibitor ICK/KRP genes upregulates the E2F pathway and increases cell proliferation, and organ and seed sizes in Arabidopsis
Authors: Cheng Yan , Cao Ling , Wang Sheng , Li Yongpeng , Shi Xianzong , Liu Han , Li Lixia , Zhang Zhengli , Fowke Larry C. , Wang Hong , Zhou Yongming
Published: May 2013

The ICK/KRP cyclin‐dependent kinase (CDK) inhibitors are important plant cell cycle factors sharing only limited similarity with the metazoan CIP/KIP family of CDK inhibitors. Little is known about the specific functions of different ICK/KRP genes in planta. In this study, we created double and multiple mutants from five single Arabidopsis ICK/KRP T‐DNA mutants, and used a set of 20 lines for the functional investigation of the important gene family. There were gradual increases in CDK activity from single to multiple mutants, indicating that ICK/KRPs act as CDK inhibitors under normal physiological conditions in plants. Whereas lower‐order mutants showed no morphological phenotypes, the ick1 ick2 ick6 ick7 and ick1 ick2 ick5 ick6 ick7 mutants had a slightly altered leaf shape. The quintuple mutant had larger cotyledons, leaves, petals and seeds than the wild‐type control. At the cellular level, the ICK/KRP mutants had more but smaller cells in all the organs examined. These phenotypic effects became more apparent as more ICK/KRPs were downregulated, suggesting that to a large extent ICK/KRPs function in plants redundantly in a dosage‐dependent manner. Analyses also revealed increased expression of E2F‐dependent genes, and elevated RBR1 as well as an increased level of phospho‐RBB1 protein in the quintuple mutant. Thus, downregulation of multiple ICK/KRP genes increases CDK activity, upregulates the E2F pathway and stimulates cell proliferation, resulting in increased cell numbers, and larger organs and seeds.
Genome‐wide transcript analysis of early maize leaf development reveals gene cohorts associated with the differentiation of C4 Kranz anatomy
Authors: Wang Peng , Kelly Steven , Fouracre Jim P. , Langdale Jane A.
Published: May 2013

Photosynthesis underpins the viability of most ecosystems, with C4 plants that exhibit ‘Kranz’ anatomy being the most efficient primary producers. Kranz anatomy is characterized by closely spaced veins that are encircled by two morphologically distinct photosynthetic cell types. Although Kranz anatomy evolved multiple times, the underlying genetic mechanisms remain largely elusive, with only the maize scarecrow gene so far implicated in Kranz patterning. To provide a broader insight into the regulation of Kranz differentiation, we performed a genome‐wide comparative analysis of developmental trajectories in Kranz (foliar leaf blade) and non‐Kranz (husk leaf sheath) leaves of the C4 plant maize. Using profile classification of gene expression in early leaf primordia, we identified cohorts of genes associated with procambium initiation and vascular patterning. In addition, we used supervised classification criteria inferred from anatomical and developmental analyses of five developmental stages to identify candidate regulators of cell‐type specification. Our analysis supports the suggestion that Kranz anatomy is patterned, at least in part, by a SCARECROW/SHORTROOT regulatory network, and suggests likely components of that network. Furthermore, the data imply a role for additional pathways in the development of Kranz leaves.
Arabidopsis plants lacking PsbQ and PsbR subunits of the oxygen‐evolving complex show altered PSII super‐complex organization and short‐term adaptive mechanisms
Authors: Allahverdiyeva Yagut , Suorsa Marjaana , Rossi Fabio , Pavesi Andrea , Kater Martin M. , Antonacci Alessia , Tadini Luca , Pribil Mathias , Schneider Anja , Wanner Gerhard , Leister Dario , Aro Eva‐Mari , Barbato Roberto , Pesaresi Paolo
Published: May 2013

The oxygen‐evolving complex of eukaryotic photosystem II (PSII) consists of four extrinsic subunits, PsbO (33 kDa), PsbP (23 kDa), PsbQ (17 kDa) and PsbR (10 kDa), encoded by seven nuclear genes, PsbO1 (At5g66570), PsbO2 (At3g50820), PsbP1 (At1g06680), PsbP2 (At2g30790), PsbQ1 (At4g21280), PsbQ2 (At4g05180) and PsbR (At1g79040). Using Arabidopsis insertion mutant lines, we show that PsbP1, but not PsbP2, is essential for photoautotrophic growth, whereas plants lacking both forms of PsbQ and/or PsbR show normal growth rates. Complete elimination of PsbQ has a minor effect on PSII function, but plants lacking PsbR or both PsbR and PsbQ are characterized by more pronounced defects in PSII activity. Gene expression and immunoblot analyses indicate that accumulation of each of these proteins is highly dependent on the presence of the others, and is controlled at the post‐transcriptional level, whereas PsbO stability appears to be less sensitive to depletion of other subunits of the oxygen‐evolving complex. In addition, comparison of levels of the PSII super‐complex in wild‐type and mutant leaves reveals the importance of the individual subunits of the oxygen‐evolving complex for the supramolecular organization of PSII and their influence on the rate of state transitions.
Suggestions for the diagnosis and elimination of hepatitis E virus in pigs used for xenotransplantation
Authors: Busby Stacey‐Ann , Crossan Claire , Godwin Jon , Petersen Bjoern , Galli Cesare , Cozzi Emanuele , Takeuchi Yasu , Scobie Linda
Published: May 2013

The hepatitis E virus (HEV) is considered a zoonotic pathogen. In xenotransplantation, given the high prevalence of HEV infection in pigs, the risk of zoonotic transmission from a porcine source is considered high. Currently no clear data are available on how to diagnose and eliminate HEV in herds used for medical purposes and the importance of viral infection at the stage of harvest. In this study, several groups of animals currently used for medical purposes were found RNA positive in both serum and faeces for HEV genotype 3. In addition, viraemia was found in animals up to 3.6 yr of age, which is much longer than originally expected. Herd transmission rates appeared to be significantly lower in animals kept under minimal barrier conditions, compared with those observed for commercial animals, and as expected, segregation of animals at an early age prevented spread of infection. This study makes suggestions to ensure appropriate detection and eradication of HEV from a donor herd to be used for xenotransplantation purposes.
Residues of Eisenstein series and the automorphic cohomology of reductive groups
Authors: Grobner Harald
Published: May 2013

Let $G$ be a connected, reductive algebraic group over a number field $F$ and let $E$ be an algebraic representation of ${G}_{\infty } $. In this paper we describe the Eisenstein cohomology ${ H}_{\mathrm{Eis} }^{q} (G, E)$ of $G$ below a certain degree ${q}_{ \mathsf{res} } $ in terms of Franke’s filtration of the space of automorphic forms. This entails a description of the map ${H}^{q} ({\mathfrak{m}}_{G} , K, \Pi \otimes E)\rightarrow { H}_{\mathrm{Eis} }^{q} (G, E)$, $q\lt {q}_{ \mathsf{res} } $, for all automorphic representations $\Pi $ of $G( \mathbb{A} )$ appearing in the residual spectrum. Moreover, we show that below an easily computable degree ${q}_{ \mathsf{max} } $, the space of Eisenstein cohomology ${ H}_{\mathrm{Eis} }^{q} (G, E)$ is isomorphic to the cohomology of the space of square-integrable, residual automorphic forms. We discuss some more consequences of our result and apply it, in order to derive a result on the residual Eisenstein cohomology of inner forms of ${\mathrm{GL} }_{n} $ and the split classical groups of type ${B}_{n} $, ${C}_{n} $, ${D}_{n} $.
Near-field effects in Green's function retrieval from cross-correlation of elastic fields: Experimental study with application to elastography
Authors: Benech N. , Brum J. , Catheline S. , Gallot T. , Negreira C.
Published: May 2013

In a lossless system, the causal and acausal Green's function for elastic waves can be retrieved by cross-correlating the elastic field at two positions. This field, composed of converging and diverging waves, is interpreted in the frame of a time-reversal process. In this work, the near-field effects on the spatio-temporal focusing of elastic waves are analyzed through the elastodynamic Green's function. Contrary to the scalar field case, the spatial focusing is not symmetric preserving the directivity pattern of a simple source. One important feature of the spatial asymmetry is its dependency on the Poisson ratio of the solid. Additionally, it is shown that the retrieval of the bulk wave speed values is affected by diffraction. The correction factor depends on the relative direction between the source and the observed field. Experimental verification of the analysis is carried out on the volume of a soft-solid. A low-frequency diffuse-like field is generated by random impacts at the sample's free surface. The displacement field is imaged using ultrasound by a standard speckle tracking technique. One important application of this work is in the estimation of the shear elastic modulus in soft biological tissues, whose quantification can be useful in non-invasive diagnosis of various diseases.
Uncertainties in predicting structure-borne sound power input into buildings
Authors: Gibbs B. M.
Published: May 2013

There has been a steady development of methods of measurement and prediction of structure-borne noise in buildings, particularly over the last two decades. In proposing and evaluating these methods, a major consideration has been the likely trade-off between accuracy and simplicity. Structure-borne sound transmission is a more complicated process than airborne sound transmission, but practitioners seek methods of prediction for the former, which are as straightforward as for the latter. In this paper a description is given of a study of multi-contact sources in buildings. The study concentrates on measurement and calculation procedures for sources and calculation procedures for receiver structures, particularly lightweight building elements. Although the study is not exhaustive, the findings point to the limitations of simplified methods, specifically the uncertainties likely as a result of reducing the data sets and computational effort, and the discrepancies resulting from simplifying assumptions.
On the relationship between blast noise complaints and community annoyance
Authors: Nykaza Edward T. , Hodgdon Kathleen K. , Gaugler Trent , Krecker Peg , Luz George A.
Published: May 2013

Military installations typically rely on noise complaints to indicate adverse noise environments and often restrict the firing of certain weapons to reduce the number of noise complaints. Using complaints in this manner may also imply that the absence of complaints is an indicator of low community annoyance. The relationship between individual complaints and general community annoyance, however, is currently not established, and it is unknown whether implementing restrictions in reaction to individual complaints is an appropriate or necessary way to reduce community annoyance. This paper looks at whether there are significant differences in reported annoyance to complaint-referenced blast events and general military noise annoyance between those who complain and their non-complaining neighbors. Those who complained were significantly more annoyed to both complaint-referenced blast events and general military noise in comparison to their non-complaining neighbors. The implications of these findings are discussed in terms of range management.
Language dependent vowel representation in speech production
Authors: Mitsuya Takashi , Samson Fabienne , Ménard Lucie , Munhall Kevin G.
Published: May 2013

The representation of speech goals was explored using an auditory feedback paradigm. When talkers produce vowels the formant structure of which is perturbed in real time, they compensate to preserve the intended goal. When vowel formants are shifted up or down in frequency, participants change the formant frequencies in the opposite direction to the feedback perturbation. In this experiment, the specificity of vowel representation was explored by examining the magnitude of vowel compensation when the second formant frequency of a vowel was perturbed for speakers of two different languages (English and French). Even though the target vowel was the same for both language groups, the pattern of compensation differed. French speakers compensated to smaller perturbations and made larger compensations overall. Moreover, French speakers modified the third formant in their vowels to strengthen the compensation even though the third formant was not perturbed. English speakers did not alter their third formant. Changes in the perceptual goodness ratings by the two groups of participants were consistent with the threshold to initiate vowel compensation in production. These results suggest that vowel goals not only specify the quality of the vowel but also the relationship of the vowel to the vowel space of the spoken language.
Ultrasonic guided wave propagation across waveguide transitions: Energy transfer and mode conversion
Authors: Puthillath Padmakumar , Galan Jose M. , Ren Baiyang , Lissenden Cliff J. , Rose Joseph L.
Published: May 2013

Ultrasonic guided wave inspection of structures containing adhesively bonded joints requires an understanding of the interaction of guided waves with geometric and material discontinuities or transitions in the waveguide. Such interactions result in mode conversion with energy being partitioned among the reflected and transmitted modes. The step transition between an aluminum layer and an aluminum-adhesive-aluminum multi-layer waveguide is analyzed as a model structure. Dispersion analysis enables assessment of (i) synchronism through dispersion curve overlap and (ii) wavestructure correlation. Mode-pairs in the multi-layer waveguide are defined relative to a prescribed mode in a single layer as being synchronized and having nearly perfect wavestructure matching. Only a limited number of mode-pairs exist, and each has a unique frequency range. A hybrid model based on semi-analytical finite elements and the normal mode expansion is implemented to assess mode conversion at a step transition in a waveguide. The model results indicate that synchronism and wavestructure matching is associated with energy transfer through the step transition, and that the energy of an incident wave mode in a single layer is transmitted almost entirely to the associated mode-pair, where one exists. This analysis guides the selection of incident modes that convert into transmitted modes and improve adhesive joint inspection with ultrasonic guided waves.
Interaction of torsional and longitudinal guided waves in weakly nonlinear circular cylinders
Authors: Liu Yang , Khajeh Ehsan , Lissenden Cliff J. , Rose Joseph L.
Published: May 2013

The nonlinear forcing terms for the wave equation in general curvilinear coordinates are derived based on an isotropic homogeneous weakly nonlinear elastic material. The expressions for the nonlinear part of the first Piola-Kirchhoff stress are specialized for axisymmetric torsional and longitudinal fundamental waves in a circular cylinder. The matrix characteristics of the nonlinear forcing terms and secondary mode wave structures are manipulated to analyze the higher harmonic generation due to the guided wave mode self-interactions and mutual interactions. It is proved that both torsional and longitudinal secondary wave fields can be cumulative by a specific type of guided wave mode interactions. A method for the selection of preferred fundamental excitations that generate strong cumulative higher harmonics is formulated, and described in detail for second harmonic generation. Nonlinear finite element simulations demonstrate second harmonic generation by T(0,3) and L(0,4) modes at the internal resonance points. A linear increase of the normalized modal amplitude ratio A2/A12 over the propagation distance is observed for both cases, which indicates that mode L(0,5) is effectively generated as a cumulative second harmonic. Counter numerical examples demonstrate that synchronism and sufficient power flux from the fundamental mode to the secondary mode must occur for the secondary wave field to be strongly cumulative.
On the acoustic effects of the supraglottic structures in excised larynges
Authors: Alipour Fariborz , Finnegan Eileen
Published: May 2013

The acoustic effects of the supraglottic laryngeal structures (SGSs), including the false vocal folds (FVFs) laryngeal ventricle, and the epiglottis were investigated in an excised canine larynx model with and without these anatomical structures. The purpose of this study was to better understand the acoustic contributions of these structures to phonation. Canine larynges were prepared and mounted over a 3/4 in. tube, which supplied pressurized, heated, and humidified air. Glottal adduction was accomplished by rotating the arytenoids with a suture passed behind the vocal folds to simulate the lateral cricoarytenoid muscle action. The SGSs were kept intact in the first part of the experiment and were removed in the second part. Results indicated that when the FVFs vibrated, a low frequency component was observed in the spectral data. The excised larynx with a SGS had a limited range of frequency with subglottal pressure, while the larynx without a SGS had a larger frequency range. The excised canine larynx with a SGS oscillated with a higher phonation threshold pressure and significantly louder.
Effect of glottal dynamics in the production of shouted speech
Authors: Mittal V. K. , Yegnanarayana B.
Published: May 2013

In this paper characteristics of speech produced at different loudness levels are analyzed in terms of changes in the glottal excitation. Four loudness levels are considered in this study, namely, soft, normal, loud, and shout. The distinct changes in the excitation of the shout signal are analyzed using electroglottograph signals. The open and closed phases of the glottal vibration are distinctly different for shout signals, in comparison with those for normal speech. It is generally difficult to derive the glottal pulse information from the speech signal due to limitations in inverse filtering. Hence, the effects of changes in the excitation are examined by analyzing the speech signal using methods that can capture the temporal variations of the spectral features. In particular, the recently proposed methods of zero-frequency filtering and zero-time liftering are used in this analysis. It is shown that the closed phase behavior of the excitation at different loudness levels can be seen in the temporal variation of spectral energy in the low frequency (LF) (<400 Hz) region. The ratio of the LF to high frequency energy clearly discriminates the speech produced at different loudness levels. These distinctions in the excitation features are also observed in different vowel contexts and across several speakers.
Measurement of acoustic characteristics of Japanese Buddhist temples in relation to sound source location and direction
Authors: Soeta Yoshiharu , Shimokura Ryota , Kim Yong Hee , Ohsawa Tomohiro , Ito Ken
Published: May 2013

Although temples are important buildings in the Buddhist community, the acoustic quality has not been examined in detail. Buddhist monks change the location and direction according to the ceremony, and associated acoustical changes have not yet been examined scientifically. To discuss the desired acoustics of temples, it is necessary to know the acoustic characteristics appropriate for each phase of a ceremony. In this study, acoustic measurements were taken at various source locations and directions in Japanese temples. A directional loudspeaker was used as the source to provide vocal acoustic fields, and impulse responses were measured and analyzed. The speech transmission index was higher and the interaural cross-correlation coefficient was lower for the sound source directed toward the side wall than that directed toward the altar. This suggests that the change in direction improves speech intelligibility, and the asymmetric property of direct sound and complex reflections from the altar and side wall increases the apparent source width. The large and coupled-like structure of the altar of a Buddhist temple may have reinforced the reverberation components and the table in the altar, which is called the “syumidan,” may have decreased binaural coherence.
Characterization of acoustic emissions resulting from particle collision with a stationary bubble
Authors: Zhang Wen , Spencer Steven J. , Coghill Peter
Published: May 2013

The present work characterizes the acoustic emissions resulting from the collision of a particle driven under gravity with a captive bubble. Conventional methods to investigate the bubble particle collision interaction model measure a descriptive parameter known as the collision time. During such a collision, particle impact may cause a strong deformation and a following oscillation of the bubble–particle interface generates detectable passive acoustic emissions (AE). Experiments and models presented show that the AE frequency monotonically decreases with the particle radius and is independent of the impact velocity, whereas the AE amplitude has a more complicated relationship with impact parameters.
Estimating critical bandwidths of temporal sensitivity to low-frequency amplitude modulation
Authors: Shim Allison I. , Berg Bruce G.
Published: May 2013

Auditory filter bandwidths are measured for a temporal process using an amplitude-modulation detection task. The signal is a 200 Hz wide, sinusoidally amplitude-modulated band of noise centered within an unmodulated notched-noise masker. A modulation rate of 10 Hz is used to avoid possible information loss at more central processing levels for high modulation rates. Threshold functions are obtained for 10–14 notch widths for each of four different center frequencies (0.6, 1, 2, and 4 kHz) to determine the maximum notch width at which the masker has an effect. The ratio of center frequency to maximum notch width is ∼2 at all center frequencies. It is proposed that the bandwidths observed in temporal tasks, which are consistently greater than expected from the viewpoint of critical band theory, be characterized as “temporal critical bands.” This proposal does not oppose, but provides a complement to the traditional critical band obtained in tasks involving spectral discrimination.
Spectral-envelope–group-delay models for transients
Authors: Shenoy Ravi R. , Seelamantula Chandra Sekhar
Published: May 2013

Transient signals such as plosives in speech or Castanets in audio do not have a specific modulation or periodic structure in time domain. However, in the spectral domain they exhibit a prominent modulation structure, which is a direct consequence of their narrow time localization. Based on this observation, a spectral-domain AM-FM model for transients is proposed. The spectral AM-FM model is built starting from real spectral zero-crossings. The AM and FM correspond to the spectral envelope (SE) and group delay (GD), respectively. Taking into account the modulation structure and spectral continuity, a local polynomial regression technique is proposed to estimate the GD function from the real spectral zeros. The SE is estimated based on the phase function computed from the estimated GD. Since the GD estimation is parametric, the degree of smoothness can be controlled directly. Simulation results based on synthetic transient signals generated using a beta density function are presented to analyze the noise-robustness of the SEGD model. Three specific applications are considered: (1) SEGD based modeling of Castanet sounds; (2) appropriateness of the model for transient compression; and (3) determining glottal closure instants in speech using a short-time SEGD model of the linear prediction residue.
The role of pitch and timing cues in the perception of phrasal grouping in Seoul Korean
Authors: Jeon Hae-Sung , Nolan Francis
Published: May 2013

This paper reports two experiments in which listeners detected prosodic group boundaries in Seoul Korean speech, investigating how pitch and timing cues collaborate or compete with each other. Two types of timing cues, compensatory lengthening and group-final lengthening, were employed. The results show that both pitch and timing have demarcative functions which are exploited by listeners. However, listeners relied more on timing than pitch and this may be because in the experiments the pitch contour variations were limited to a small number of phonological categories, whereas temporal variations were more gradient. In addition, group-final lengthening was a more robust cue to the prosodic boundary than compensatory lengthening, and the integration of pitch and timing cues seems to be context-dependent. The results highlight the significance of local information in the universal grouping process and that the precise nature of the cues affect the way they integrate in perception.
Synthesis of laughter by modifying excitation characteristics
Authors: Thati Sathya Adithya , Kumar K Sudheer , Yegnanarayana B.
Published: May 2013

In this paper, a method to synthesize laughter by modifying the excitation source information is presented. The excitation source information is derived by extracting epoch locations and instantaneous fundamental frequency using zero frequency filtering approach. The zero frequency filtering approach is modified to capture the rapidly varying instantaneous fundamental frequency in natural laugh signals. The nature of variation of excitation features in natural laughter is examined to determine the features to be incorporated in the synthesis of a laugh signal. Features such as pitch period and strength of excitation are modified in the utterance of vowel /a/ or /i/ to generate the laughter signal. Frication is also incorporated wherever appropriate. Laugh signal is generated by varying parameters at both call level and bout level. Experiments are conducted to determine the significance of different features in the perception of laughter. Subjective evaluation is performed to determine the level of acceptance and quality of synthesis of the synthesized laughter signal for different choices of parameter values and for different input types.
Latency of tone-burst-evoked auditory brain stem responses and otoacoustic emissions: Level, frequency, and rise-time effects
Authors: Rasetshwane Daniel M. , Argenyi Michael , Neely Stephen T. , Kopun Judy G. , Gorga Michael P.
Published: May 2013

Simultaneous measurement of auditory brain stem response (ABR) and otoacoustic emission (OAE) delays may provide insights into effects of level, frequency, and stimulus rise-time on cochlear delay. Tone-burst-evoked ABRs and OAEs (TBOAEs) were measured simultaneously in normal-hearing human subjects. Stimuli included a wide range of frequencies (0.5–8 kHz), levels (20–90 dB SPL), and tone-burst rise times. ABR latencies have orderly dependence on these three parameters, similar to previously reported data by Gorga et al. [J. Speech Hear. Res. 31, 87–97 (1988)]. Level dependence of ABR and TBOAE latencies was similar across a wide range of stimulus conditions. At mid-frequencies, frequency dependence of ABR and TBOAE latencies were similar. The dependence of ABR latency on both rise time and level was significant; however, the interaction was not significant, suggesting independent effects. Comparison between ABR and TBOAE latencies reveals that the ratio of TBOAE latency to ABR forward latency (the level-dependent component of ABR total latency) is close to one below 1.5 kHz, but greater than two above 1.5 kHz. Despite the fact that the current experiment was designed to test compatibility with models of reverse-wave propagation, existing models do not completely explain the current data.
Target identification using relative level in multi-talker listening
Authors: Kitterick Pádraig T. , Clarke Emmet , O'Shea Charlotte , Seymour Josephine , Quentin Summerfield A.
Published: May 2013

Previous studies have suggested that listeners can identify words spoken by a target talker amidst competing talkers if they are distinguished by their spatial location or vocal characteristics. This “direct” identification of individual words is distinct from an “indirect” identification based on an association with other words (call-signs) that uniquely label the target. The present study assessed listeners' ability to use differences in presentation level between a target and overlapping maskers to identify target words. A new sentence was spoken every 800 ms by an unpredictable talker from an unpredictable location. Listeners reported color and number words in a target sentence distinguished by a unique call-sign. When masker levels were fixed, target words could be identified directly based on their relative level. Speech-reception thresholds (SRTs) were low (−12.9 dB) and were raised by 5 dB when direct identification was disrupted by randomizing masker levels. Thus, direct identification is possible using relative level. The underlying psychometric functions were monotonic even when relative level was a reliable cue. In a further experiment, indirect identification was prevented by removing the unique call-sign cue. SRTs did not change provided that other cues were available to identify target words directly. Thus, direct identification is possible without indirect identification.
Perceptual limits for detecting interaural-cue manipulations measured in reverberant settings
Authors: Klockgether Stefan , van Dorp Schuitman Jasper , van de Par Steven
Published: May 2013

In this study, binaural room impulse responses (BRIRs) were manipulated to determine the just noticeable differences in the interaural time delay (ITD), interaural level difference (ILD), and interaural cross-correlation (ICC) in reverberant settings. The BRIR were split in two sections, the first 75–150 ms of the BRIR was found to be direction dependent, and for this first part either an extra ITD or ILD was applied. These manipulations were expected to change the perceived direction of the sound source. Changes in the ICC were applied to the remaining part of the BRIR, which was expected to change the overall spatial impression, but not the perceived location. Each of these three differently manipulated BRIRs was convolved with an anechoic musical instrument, and the just noticeable change in ITD, ILD, or ICC was determined in a listening experiment. Due to the convolution with a temporally varying musical instrument stimulus, a complex spectrotemporal pattern of binaural cues is created. An analysis of these cues will be presented and it will be compared to the listening test results. This analysis will be based on a model of human auditory processing, which predicts perceptual cues related to room acoustic perception.
Accuracy in the acoustical parameters evaluation according to ISO-3382
Authors: Arana Miguel , San Martin Ricardo , Arregui Abel , Machin Jorge
Published: May 2013

An exhaustive characterization of the new auditorium of the Navarre Conservatory of Music (Pamplona, Spain) has been carried out. All monaural acoustic parameters in all seats (375) have been measured for three source positions on the stage. For acoustic characterization, countless results can be obtained in accordance (in all cases) with the views of the ISO-3382 for the presentation of the results. The spatial dispersion for each source position and combinations thereof will be shown. Finally, the accuracy on the acoustic evaluation of the room will be discussed from a statistical point of view.
Straw bale sound insulation: Blowing away the chaff
Authors: Dance Stephen , Herwin Paul
Published: May 2013

Popular opinion states that straw bale walls are good at isolating sound. Cheap load bearing straw bale houses could contribute substantially to low carbon sustainable construction. However, literature on the subject was found to be highly anecdotal. The paper presents a summary of nine laboratory and field sound insulation test reports and two especially commissioned tests. Data were compared to European party wall sound insulation criteria, and it was found that straw walls could perform as well as, but sometimes worse than, conventional constructions, due to poor performance at low frequencies. Better performance could help to promote the use of straw bales in multi-unit housing. It was found that by adding a plasterboard layer on studs to just one side of a plastered straw bale wall would allow the construction to pass all of the criteria reviewed.
From felt to fungus: New materials and applications—Focus on sustainability
Authors: Schuette Dawn , Pfeiffer Scott
Published: May 2013

A two-part presentation of new materials for use in architectural acoustics. This presentation emphasizes new materials or new applications of standard products that provide acoustic benefit in a highly sustainable context. The companion session is presented in “New Materials for Architectural Acoustics.” Current trends in architecture are bringing more organic approaches to the use of natural materials. Exploiting these trends with approaches that have definable acoustic behavior leads to more flexibility in architectural design and yields acoustical application of materials that are not traditionally part of the acoustical treatment vocabulary. Case studies will be presented featuring new materials and/or methods being employed for sustainable acoustic solutions.
Expressiveness of temperature-induced changes in backscattered energy in conventional B-mode images
Authors: Teixeira Cesar A. , von Kruguer Marco , Alvarenga André V. , Pereira Wagner C.
Published: May 2013

Changes on conventional B-mode images have been correlated with temperature, aiming to develop a reliable method for noninvasive temperature estimation. The assumption is that temperature variations induce wave propagation changes that modify the backscattered ultrasound signal and these changes have an expression in ultrasonographic images. One of the main effects is the change on the image intensity that is mainly caused by temperature-related changes in backscattered energy (CBE) from tissue inhomogeneities. It is reported that CBE is dependent on medium speed-of-sound and density, behaving in different ways for lipid or aqueous scatterers. In this paper, we demonstrate that CBE has an expression on B-mode images recorded from conventional ultrasound scanners. We observed that different regions have positive, negative, or undefined correlations with temperature, and that this behavior is due to the dependence of CBE with scatterers type. This differentiated behavior enables the segmentation of different structures inside the same tissue. Our experimental setup consisted in the temperature elevation from 36 to 44 °C (hyperthermia range) of ex-vivo tissue samples. We considered bovine muscle and porcine muscle and fat. For both samples, we observed coherent segmentations of the different structures, pointing for a potential clinical application of the proposed analysis.
Ultrasonic projection imaging of biological media
Authors: Opielinski Krzysztof J. , Gudra Tadeusz
Published: May 2013

The study presents the method of ultrasonic projection imaging of biological media, using single ultrasonic probes and 2-D piezoelectric transducer arrays. Dedicated research stands were set up and used to perform ultrasonic projection scanning of various biological media (and phantoms of the media) that were submerged in water. Based on such measurements, images of the heterogeneous internal structure of the studied objects were obtained, which show two-dimensional distributions of the projection values of acoustic parameters. Those parameters were derived from recorded pulses of ultrasonic wave transmitted sequentially through a fixed projection surface. The obtained projection images were analyzed with respect to the method and quality of representation of the studied structures. Additionally, contrast resolution of ultrasonic projection images of the heterogeneous structure of a biological medium was estimated in relation to the size of the heterogeneity and with respect to scanning resolution and longitudinal resolution. Ultrasonic projection imaging can be applied in medicine for diagnostic examination of women's breast.
Heat transfer enhancement through thermoacoustically driven streaming
Authors: Ali Randall A. , Garrett Steven L.
Published: May 2013

We recently reported on a simple standing-wave thermoacoustic engine that was intended for use as a self-powered monitor of temperature within a resonator that was similar to a nuclear fuel rod [J. Acoust. Soc. Am. 132(3), Pt. 2, 1993–1994 (2012)]. An additional potential benefit of such a device is the enhanced heat transfer between the heat source and the surrounding coolant produced by the acoustic streaming generated by the high-amplitude acoustic standing wave within the resonator. By adding a remotely operated linear actuator that can depress a valve at the ambient-temperature end of the resonator, we are able to squelch the acoustic resonance by modification of that boundary condition without changing any other operating parameters (e.g., heater power). We will report heat transfer measurements made in a calorimeter at several input thermal power levels, with and without the presence of the thermoacoustic oscillations. [Work supported by the U.S. Department of Energy.]
Acoustic characteristics of a flexible sound generator based on thermoacoustic effect
Authors: Sugimoto Takehiro , Nakajima Yoshiki
Published: May 2013

A flexible sound generator based on the thermoacoustic effect was proposed for use with thin and flexible devices. The sound generator was composed of three thin films made of aluminum, polyimide, and graphite. The aluminum functions as an electrode for heat radiation, the polyimide as a heat insulator, and the graphite as a heat sink. Thickness of each layer is 50 nm, 75 μm, and 40 μm, respectively. The area of the electrode is 100 mm × 4 mm. The proposed sound generator was modeled considering several boundary conditions and using the heat conduction equation. Then, radiated sound was analytically described as a function of the input signal’s frequency. Experimental measurement was carried out and the frequency response calculated by the model agreed with the measurement result. An experimental study was conducted on the relationship between the fundamental response and the harmonic distortion. Surface vibration was observed with the laser Doppler velocimeter. The observation revealed that the proposed device is a vibration-free sound generator. Detailed comparison between the calculation and the measurement will be discussed in the presentation.
Calculating guitar sound radiation by forward-propagating measured forced-oscillation patterns
Authors: Richter Jan , Münster Malte , Bader Rolf
Published: May 2013

The radiation patterns of 32 guitars are investigated. Therefore, the top and back plates are measured using a 121-microphone array, back-propagating the recorded sound field onto the guitar top and back plates. Both, the eigenvalues and the forced oscillation patterns are measured, the latter by plucking the guitar strings for all possible notes. For each note, the forced-oscillation radiation pattern is calculated for 20 partials up to 4 kHz. These radiation patterns are then forward-propagated into the surrounding space around the guitar. Considerable differences appear between the different guitars within the same frequency region in terms of shape and intensity. Also, for similar frequencies, different patterns may appear, depending on the string and note played.
Measuring the haptic behavior of an acoustic guitar as perceived by the player by means of a vibrating actuator
Authors: Giordano Marcello , Wanderley Marcelo M.
Published: May 2013

Two sets of recordings of the vibration produced by plucking the fifth and the second string of an acoustic guitar were acquired using an accelerometer secured to the neck of the instrument. Vibrations from both sets could be reproduced using a recoil-type vibrating actuator attached at the neck of the guitar. In one of the sets, salient spectral features of the original recordings were altered. We performed a preliminary study involving nine volunteer participants, blindfolded and artificially deafened using earplugs and loud white noise played through headphones. They were asked to discriminate, by holding the neck of the instrument with their left hand, between “fake” (i.e., actuator-produced) or real vibrations, produced by the experimenter plucking either string two or five. Our aim was to assess if any of the spectral features altered in the second set of recordings increased the recognition rate of actuator-produced vibrations as being “fake.” These features, if present, would then be likely to carry crucial information and should be therefore modeled with extreme care in the simulation of the haptic behavior of the instrument. Results show that, at least for string five, we were capable of identifying one feature (a peak in the vibration spectrum located at 548 Hz), which, if altered, made the recognition rate as “fake” rise, statistically significantly, from 55% to 89%.
Characterization of bridge motions on the violin using polymer sensor technology
Authors: Gidion Gunnar , Gerhard Reimund
Published: May 2013

Recent developments in minimally invasive polymer-film sensors permit the in-situ detection of mechanical vibrations in musical instruments without significantly disturbing the acoustics of the instrument. As an example, we present measurements of vibrations of a violin between the feet of the bridge and the top plate. To this end, calibrated fluoropolymer-film sensors were matched to the geometry of the bridge feet. The forces exerted on the top plate by either bridge foot can be measured separately during excitation of a string with the bow. The differences in amplitude and phase between bass and treble foot vibrations exhibit the distinctly asymmetrical nature of bridge motions, which of course also depend on the string and the note that are being played, respectively. In comparison with the simultaneously detected string vibrations and the radiated sound, the filter characteristics of the bridge are clearly identified in the spectral representation. As the bridge is also the main agent for the coupling from the body to the string, it is suggested that the observed variations in bridge motion are closely connected to the fact that the playability of a violin changes sometimes quite drastically from note to note.