bluuebunny/crossref_metadata_2025 huggingface dataset:
Disabled children and adolescents may be outsiders in the community
Authors: Fägerskiöld A.M. , Mattsson G. Glad
Published: September 2010

FÄGERSKIÖLD A.M. & MATTSSON G. Glad (2010) Disabled children and adolescents may be outsiders in the community. International Nursing Review

Background:  Most children with neurogenic bladder and bowel dysfunctions suffer from myelomeningocele and shunted hydrocephalus. Fewer such births and better treatment have led to more children reaching adulthood. Increased knowledge about their lived experiences can direct support to help them.

Aim:  The study aims to investigate how children and adolescents aged between 10 and 18 years old with neurogenic bladder and bowel dysfunction live their everyday life.

Methods:  Hermeneutic phenomenology was appropriate to investigate the participants' experiences in depth. Thirteen qualitative interviews were analysed by coding line‐by‐line in order to find the essence and themes that underpin their responses.

Findings:  The major theme being an outsider in the community, was built upon the themes, constraint and togetherness. Constraint was caused by their need for regular clean intermittent catheterization, bowel movement, aids and assistance from others, which identified a participant as being an outsider. They were only partially outsiders because they were inside the community and they enjoyed togetherness in their everyday life from their families, peers and other significant people. They appeared to be rather unaware of their problems.

Limitations:  The wide range of participants' ages was a limitation, as these young people develop a great deal between these ages; in order to guarantee confidentiality, the participants were too few to divide into groups.

Conclusions:  These young people would be helped if supported more towards independence by people inside their circle. Today, support is usually given by personal assistants and by the use of advanced techniques. Less support is given for development towards independence. Competent health‐care professionals working together with the parents should have the opportunity to provide such valuable support.
This article has been retracted and is available online only: Religion, culture and male involvement in the use of family planning: evidence from Enugu and Katsina States of Nigeria
Authors: Ujuju C. , Anyanti J. , Adebayo S.B. , Muhammad F. , Oluigbo O. , Gofwan A.
Published: September 2010

Retraction

The following article from the International Nursing Review, ‘Religion, culture and male involvement in the use of family planning: evidence from Enugu and Katsina States of Nigeria’, by C. Ujuju, J. Anyanti, S.B. Adebayo, F. Muhammad, O. Oluigbo and A. Gofwan, published online on 6 September 2010 on Wiley Online Library (http://wileyonlinelibrary.com) has been retracted by agreement between the authors, the journal Editor in Chief, Jane J.A. Robinson and Blackwell Publishing Ltd. The retraction has been agreed as not all copyright permissions had been cleared.

Jane J.A Robinson

Editor

International Nursing Review
Biological motion preference in humans at birth: role of dynamic and configural properties
Authors: Bardi Lara , Regolin Lucia , Simion Francesca
Published: September 2010

The present study addresses the hypothesis that detection of biological motion is an intrinsic capacity of the visual system guided by a non‐species‐specific predisposition for the pattern of vertebrate movement and investigates the role of global vs. local information in biological motion detection. Two‐day‐old babies exposed to a biological motion point‐light display (depicting a walking hen) and a non‐biological motion display (a rotating rigid object) preferentially looked at the biological display (Experiment 1). A new group of newborns showed themselves to be capable of discriminating, following habituation, a biological motion display from a spatially scrambled version of it (Experiment 2). However, a third group of newborns, at their first exposure to such displays, did not show any preference between them (Experiment 3). Results confirm and extend previous comparative and developmental data, supporting an inborn predisposition to attend to biological motion in humans. This ability is presumably part of an evolutionarily ancient and non‐species‐specific system predisposing animals to preferentially attend to other animals.
Neural correlates of action observation and execution in 14‐month‐old infants: an event‐related EEG desynchronization study
Authors: Marshall Peter J. , Young Thomas , Meltzoff Andrew N.
Published: September 2010

There is increasing interest in neurobiological methods for investigating the shared representation of action perception and production in early development. We explored the extent and regional specificity of EEG desynchronization in the infant alpha frequency range (6–9 Hz) during action observation and execution in 14‐month‐old infants. Desynchronization during execution was restricted to central electrode sites, while action observation was associated with a broader desynchronization across frontal, central, and parietal regions. The finding of regional specificity in the overlap between EEG responses to action execution and observation suggests that the rhythm seen in the 6–9 Hz range over central sites in infancy shares certain properties with the adult mu rhythm. The magnitude of EEG desynchronization to action perception and production appears to be smaller for infants than for adults and older children, suggesting developmental change in this measure.
Best practice principles for community‐based obesity prevention: development, content and application
Authors: King L. , Gill T. , Allender S. , Swinburn B.
Published: September 2010

Best practice in obesity prevention has generally been defined in terms of ‘what’ needs to be done while neglecting ‘how’. A multifaceted definition of best practice, which combines available evidence on what actions to take, with an established process for interpreting this information in a specific community context, provides a more appropriate basis for defining the principles of best practice in community‐based obesity prevention. Based on analysis of a range of literature, a preliminary set of principles was drafted and progressively revised through further analyses of published literature and a series of consultations. The framework for best practice principles comprises: community engagement, programme design and planning, evaluation, implementation and sustainability, and governance. Specific principles were formulated within this framework. While many principles were generic, distinctive features of obesity prevention were also covered. The engagement of end‐users influenced the design of the formatting of the outputs, which represent three levels of knowledge transfer: detailed evidence summaries, guiding questions for programme planners and a briefer set of questions for simpler communication purposes. The best practice principles provide a valuable mechanism for the translation of existing evidence and experience into the decision‐making processes for planning, implementing and evaluating the complex community‐based interventions needed for successful obesity prevention.
The membrane receptors guanylyl cyclase‐A and ‐B undergo distinctive changes in post‐translational modification during brain development
Authors: Müller Dieter , Hildebrand Mirjam , Lübberstedt Jörn , Kuhn Michaela , Middendorff Ralf
Published: September 2010

J. Neurochem. (2010) 115, 1024–1034.

Temporal carbohydrate expression patterns at cell surfaces are thought to be of crucial regulatory significance during developmental processes. Hitherto, however, data on individual membrane proteins undergoing development‐associated changes in glycosylation are sparsely. Here, we show that the two natriuretic peptide receptors, guanylyl cyclase‐A (GC‐A) and GC‐B are subject to pronounced size alterations in the rat brain between postnatal day 1 and adult. Comparable size changes were not detectable for GC‐A and GC‐B in peripheral tissues and for three other membrane proteins (insulin receptor, insulin‐like growth factor‐II/mannose‐6‐phoshate receptor, neutral endopeptidase) in brain, indicating remarkable specificity. As revealed by treatments with carbohydrate‐digesting enzymes, both GC‐A and GC‐B are hyperglycosylated at N‐linked glycosylation sites in the developing brain. At postnatal day 1, the vast majority of GC‐B (but not GC‐A) molecules contain additionally an O‐linked carbohydrate modification of about 1 kDa in mass and a further modification of similar size which is resistant to enzymatic removal. The glycoforms exhibited functional activity in membrane GC assays, indicating proper folding and signaling capability. These data link recently reported roles of natriuretic peptides during brain development for the first time with specific glycosylation states of their cyclic GMP‐generating receptors.
Regulation of protein kinase C Apl II by serotonin receptors in Aplysia
Authors: Nagakura Ikue , Dunn Tyler W. , Farah Carole Abi , Heppner Andrew , Li Flora F. , Sossin Wayne S.
Published: September 2010

J. Neurochem. (2010) 115, 994–1006.

Serotonin (5‐hydroxytryptamine, 5HT) is the neurotransmitter that mediates dishabituation in Aplysia. Serotonin mediates this behavioral change through the reversal of synaptic depression in sensory neurons (SNs). However, the 5HT receptors present in SNs and in particular, the receptor important for activation of protein kinase C (PKC) have not been fully identified. Using a recent genome assembly of Aplysia, we identified new receptors from the 5HT2, 5HT4, and 5HT7 families. Using RT‐PCR from isolated SNs, we found that three 5HT receptors, 5HT1Apl(a), 5HT2Apl, and 5HT7Apl were expressed in SNs. These receptors were cloned and expressed in a heterologous system. In this system, 5HT2Apl could significantly translocate PKC Apl II in response to 5HT and this was blocked by pirenperone, a 5HT2 receptor antagonist. Surprisingly, pirenperone did not block 5HT‐mediated translocation of PKC Apl II in SNs, nor 5HT‐mediated reversal of depression. Expression of 5HT1Apl(a) in SNs or genistein, an inhibitor of tyrosine kinases inhibited both PKC translocation and reversal of depression. These results suggest a non‐canonical mechanism for the translocation of PKC Apl II in SNs.
Carbonylated proteins are eliminated during reproduction in C. elegans
Authors: Goudeau Jérôme , Aguilaniu Hugo
Published: September 2010

Oxidatively damaged proteins accumulate with age in many species (Stadtman (1992) Science257, 1220–1224). This means that damage must be reset at the time of reproduction. To visualize this resetting in the roundworm Caenorhabditis elegans, a novel immunofluorescence technique that allows the detection of carbonylated proteins in situ was developed. The application of this technique revealed that carbonylated proteins are eliminated during C. elegans reproduction. This purging occurs abruptly within the germline at the time of oocyte maturation. Surprisingly, the germline was markedly more oxidized than the surrounding somatic tissues. Because distinct mechanisms have been proposed to explain damage elimination in yeast and mice (Aguilaniu et al. (2003) Science299, 1751–1753; Hernebring et al. (2006) Proc Natl Acad Sci USA103, 7700–7705), possible common mechanisms between worms and one of these systems were tested. The results show that, unlike in yeast (Aguilaniu et al. (2003) Science299, 1751–1753; Erjavec et al. (2008) Proc Natl Acad Sci USA105, 18764–18769), the elimination of carbonylated proteins in worms does not require the presence of the longevity‐ensuring gene, SIR‐2.1. However, similar to findings in mice (Hernebring et al. (2006) Proc Natl Acad Sci USA103, 7700–7705), proteasome activity in the germline is required for the resetting of carbonylated proteins during reproduction in C. elegans. Thus, oxidatively damaged proteins are eliminated during reproduction in worms through the proteasome. This finding suggests that the resetting of damaged proteins during reproduction is conserved, therefore validating the use of C. elegans as a model to study the molecular basis of damage elimination.
Estimating a Primal Model of Regional Crop Supply in the European Union
Authors: Jansson Torbjörn , Heckelei Thomas
Published: September 2010

This article estimates behavioural parameters of the quadratic regional supply models in the modelling system CAPRI. Using the time‐series data in the CAPRI database, we directly estimate the optimality conditions using a Bayesian highest posterior density estimator. After discarding regions with insufficient data, parameters for up to 23 crop production activities with related inputs, outputs, prices and behavioural functions are estimated for 219 regions in EU‐27. The results are systematically compared with the outcomes of other studies. For crop aggregates (e.g. cereals, oilseeds, etc.) at the national level, the estimated own price elasticities of supply are found to be in a plausible range. On a regional level and for individual crops, the picture is much more diverse. As far as we know, there is no other study of similar regional and product coverage.
Asset versus consumption poverty and poverty dynamics in rural Ethiopia
Authors: Liverpool‐Tasie Lenis Saweda O. , Winter‐Nelson Alex
Published: September 2010

Several studies have shown conceptually that assets form a more robust basis for identifying the poor than do flow variables like expenditures or income. Asset‐based poverty classification can be used to distinguish structural from stochastic poverty and can enable projection of poverty dynamics through time. Nonetheless, little work has empirically compared poverty measurement based on assets and expenditures to indicate the practical implications of the choice of poverty measure. This article uses panel data (between 1994 and 2004) from Ethiopia to generate asset‐ and expenditures‐based poverty classifications. Asset dynamics are then explored to test for the existence of multiple asset index equilibria that could constitute evidence of poverty traps. Results provide evidence of multiple equilibria and show that the asset‐based poverty classifications predict future asset and expenditures poverty status more accurately than expenditures‐based measures. The findings confirm that the asset‐based measure could be used to more carefully target poverty interventions.
An otolith microchemistry study of possible relationships between the origins of leptocephali of European eels in the Sargasso Sea and the continental destinations and relative migration success of glass eels
Authors: Martin J. , Daverat F. , Pécheyran C. , Als T. D. , Feunteun E. , Réveillac E.
Published: September 2010

Martin J, Daverat F, Pécheyran C, Als TD, Feunteun E, Réveillac E. An otolith microchemistry study of possible relationships between the origins of leptocephali of European eels in the Sargasso Sea and the continental destinations and relative migration success of glass eels. Ecology of Freshwater Fish 2010: 19: 627–637. © 2010 John Wiley & Sons A/S

Abstract –  Little is known about the extent to which Atlantic eels coming from different European rivers converge on the same spawning site. Our aim was to evaluate the spatial homogeneity of eel spawning area(s) with an otolith microchemistry approach. This work compared the elemental signatures of otolith’s core region of Anguilla anguilla leptocephali caught in the Sargasso Sea in 2007 with those of glass eels and elvers sampled in European estuaries during 2006, 2008 and 2009. Using laser ablation inductively coupled plasma mass spectrometry, the same annular ablation trajectory along the first feeding mark was applied on otoliths of glass eels, elvers and leptocephali. The concentrations of thirteen isotopes in the otoliths of glass eels/elvers did not vary among three annual cohorts collected in eleven European locations. However, otolith elemental fingerprints of leptocephali differed significantly from glass eels otolith’s signature. Although the mechanisms that regulate the differences in trace element signatures among leptocephali and glass eels/elvers are unknown, we propose that the sampled glass eels/elvers were born in a spawning site or region where favourable transport and/or feeding conditions occurred. Conversely, the leptocephali may have been sampled in a less favourable region in the Sargasso Sea, with a low probability of reaching continental growth areas.
Effectiveness of mechanical tongue cleaning on breath odour and tongue coating: a systematic review
Authors: Van der Sleen MI , Slot DE , Van Trijffel E , Winkel EG , Van der Weijden GA
Published: September 2010

To cite this article:
 
Int J Dent Hygiene 8, 2010; 258–268 DOI: 10.1111/j.1601‐5037.2010.00479.x Van der Sleen MI, Slot DE, Van Trijffel E, Winkel EG, Van der Weijden GA. Effectiveness of mechanical tongue cleaning on breath odour and tongue coating: a systematic review.

Abstract:  Background:  The objective of this review was to summarize the available evidence regarding the effects of mechanical tongue cleaning compared with no mechanical tongue cleaning on breath odour and tongue coating (TC).

Methods:  PubMed‐MEDLINE, EMBASE and Cochrane‐CENTRAL were searched to identify potentially relevant studies. The inclusion criteria included the following: randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs) conducted in humans in good general health (no systemic disorders) and a patient age of ≥17 years. For the intervention, we considered tongue cleaning [the use of a tongue scraper (TS) or tongue brush (TB)] and for the control, brushing only (B) groups. Clinical parameters such as volatile sulphur compound concentration, organoleptic scores and TC were the outcome variables of interest. Study selection, quality assessment and data extraction were carried out by two independent reviewers.

Results:  After screening of the titles and abstracts and subsequent full text reading of the potential papers, we identified five publications that met the eligibility criteria and provided seven experiments. The five studies consisted of three RCTs and two CCTs. All experiments show a positive effect of mechanical tongue cleaning in addition to toothbrushing on various parameters of oral malodour.

Conclusions:  This review demonstrated that mechanical approaches, such as tongue brushing or tongue scraping to clean the dorsum of the tongue, have the potential to successfully reduce breath odour and TC. However, data concerning the effect of mechanical tongue cleaning on chronic oral malodour (halitosis) are insufficient.
The effect of zinc oxide nanoparticles on the structure of the periplasmic domain of the Vibrio cholerae ToxR protein
Authors: Chatterjee Tanaya , Chakraborti Soumyananda , Joshi Prachi , Singh Surinder P , Gupta Vinay , Chakrabarti Pinak
Published: September 2010

Proteins adsorbed on nanoparticles (NPs) are being used as biosensors and in drug delivery. However, our understanding of the effect of NPs on the structure of proteins is still in a nascent state. In this work we report the unfolding behavior of the periplasmic domain of the ToxR protein (ToxRp) of Vibrio cholerae on zinc oxide (ZnO) nanoparticles with a diameter of 2.5 nm. This protein plays a crucial role in regulating the expression of several virulence factors in the pathogenesis of cholera. Thermodynamic analysis of the equilibrium of unfolding, induced both by urea and by guanidine hydrochloride (GdnHCl), and measured by fluorescence spectroscopy, revealed a two‐state process. NPs increased the susceptibility of the protein to denaturation. The midpoints of transitions for the free and the NP‐bound ToxRp in the presence of GdnHCl were 1.5 and 0.5 m respectively, whereas for urea denaturation, the values were 3.3 and 2.4 m, respectively. Far‐UV CD spectra showed a significant change in the protein conformation upon binding to ZnO NPs, which was characterized by a substantial decrease in the α‐helical content of the free protein. Isothermal titration calorimetry, used to quantify the thermodynamics of binding of ToxRp with ZnO NPs, showed an exothermic binding isotherm (ΔH = −9.8 kcal·mol−1 and ΔS = −5.17 cal·mol−1·K−1).
Expression of cholinesterases in human kidney and its variation in renal cell carcinoma types
Authors: Muñoz‐Delgado Encarnación , Montenegro María Fernanda , Campoy Francisco Javier , Moral‐Naranjo María Teresa , Cabezas‐Herrera Juan , Kovacs Gyula , Vidal Cecilio J.
Published: September 2010

Despite the aberrant expression of cholinesterases in tumours, the question of their possible contribution to tumorigenesis remains unsolved. The identification in kidney of a cholinergic system has paved the way to functional studies, but details on renal cholinesterases are still lacking. To fill the gap and to determine whether cholinesterases are abnormally expressed in renal tumours, paired pieces of normal kidney and renal cell carcinomas (RCCs) were compared for cholinesterase activity and mRNA levels. In studies with papillary RCC (pRCC), conventional RCC, chromophobe RCC, and renal oncocytoma, acetylcholinesterase activity increased in pRCC (3.92 ± 3.01 mU·mg−1, P = 0.031) and conventional RCC (2.64 ± 1.49 mU·mg−1, P = 0.047) with respect to their controls (1.52 ± 0.92 and 1.57 ± 0.44 mU·mg−1). Butyrylcholinesterase activity increased in pRCC (5.12 ± 2.61 versus 2.73 ± 1.15 mU·mg−1, P = 0.031). Glycosylphosphatidylinositol‐linked acetylcholinesterase dimers and hydrophilic butyrylcholinesterase tetramers predominated in control and cancerous kidney. Acetylcholinesterase mRNAs with exons E1c and E1e, 3′‐alternative T, H and R acetylcholinesterase mRNAs and butyrylcholinesterase mRNA were identified in kidney. The levels of acetylcholinesterase and butyrylcholinesterase mRNAs were nearly 1000‐fold lower in human kidney than in colon. Whereas kidney and renal tumours showed comparable levels of acetylcholinesterase mRNA, the content of butyrylcholinesterase mRNA was increased 10‐fold in pRCC. The presence of acetylcholinesterase and butyrylcholinesterase mRNAs in kidney supports their synthesis in the organ itself, and the prevalence of glycosylphosphatidylinositol‐anchored acetylcholinesterase explains the splicing to acetylcholinesterase‐H mRNA. The consequences of butyrylcholinesterase upregulation for pRCC growth are discussed.

Structured digital abstract

MINT‐7992181: BuChE (uniprotkb:P06276) and BuChE (uniprotkb:P06276) bind (MI:0407) by chromatography technology (MI:0091)

MINT‐7992175: AChE (uniprotkb:P22303) and AChE (uniprotkb:P22303) bind (MI:0407) by chromatography technology (MI:0091)
The cobordism group of homology cylinders
Authors: Cha Jae Choon , Friedl Stefan , Kim Taehee
Published: September 2010

Garoufalidis and Levine introduced the homology cobordism group of homology cylinders over a surface. This group can be regarded as an enlargement of the mapping class group. Using torsion invariants, we show that the abelianization of this group is infinitely generated provided that the first Betti number of the surface is positive. In particular, this shows that the group is not perfect. This answers questions of Garoufalidis and Levine, and Goda and Sakasai. Furthermore, we show that the abelianization of the group has infinite rank for the case that the surface has more than one boundary component. These results also hold for the homology cylinder analogue of the Torelli group.
Wafer-scale epitaxial graphene growth on the Si-face of hexagonal SiC (0001) for high frequency transistors
Authors: Dimitrakopoulos Christos , Lin Yu-Ming , Grill Alfred , Farmer Damon B. , Freitag Marcus , Sun Yanning , Han Shu-Jen , Chen Zhihong , Jenkins Keith A. , Zhu Yu , Liu Zihong , McArdle Timothy J. , Ott John A. , Wisnieff Robert , Avouris Phaedon
Published: September 2010

Up to two layers of epitaxial graphene have been grown on the Si-face of 2 in. SiC wafers exhibiting room-temperature Hall mobilities up to 2750 cm2 V−1 s−1, measured from ungated, large, 160×200 μm2 Hall bars, and up to 4000 cm2 V−1 s−1, from top-gated, small, 1×1.5 μm2 Hall bars. The growth process involved a combination of a cleaning step of the SiC in a Si-containing gas, followed by an annealing step in argon for epitaxial graphene formation. The structure and morphology of this graphene has been characterized using atomic force microscopy, high resolution transmission electron microscopy, and Raman spectroscopy. Furthermore, top-gated radio frequency field-effect transistors (rf-FETs) with a peak cutoff frequency fT of 100 GHz for a gate length of 240 nm were fabricated using epitaxial graphene grown on the Si-face of SiC that exhibited Hall mobilities up to 1450 cm2 V−1 s−1 from ungated Hall bars and 1575 cm2 V−1 s−1 from top-gated ones. This is by far the highest cutoff frequency measured from any kind of graphene.
Radioisotope-powered ion gauge with super high stability, long life, and large sensitivity range from ultrahigh vacuum to high pressure
Authors: Lu Yuerui , Lal Amit
Published: September 2010

The authors report the radioisotope-powered ion gauge (RPIG) using the safe, low activity, planar radioactive N63i beta thin-film source as the cold cathode. RPIG has both high stability and long lifetime with N63i half-life of 100.1 years. The authors experimentally demonstrate an ultrahigh sensor dynamic range, from high vacuum (10−6 Torr) to high pressure (103 Torr), which is the largest sensitivity range among all the reported pressure sensors. With high source stability independent of temperature, and its self-powered nature, RPIG is a promising candidate for pressure measurement, which needs extreme low temperature or high temperature, in microsystems where power consumption and system complexity need to be minimized.
Numerical analysis of biosonar beamforming mechanisms and strategies in bats
Authors: Müller Rolf
Published: September 2010

Beamforming is critical to the function of most sonar systems. The conspicuous noseleaf and pinna shapes in bats suggest that beamforming mechanisms based on diffraction of the outgoing and incoming ultrasonic waves play a major role in bat biosonar. Numerical methods can be used to investigate the relationships between baffle geometry, acoustic mechanisms, and resulting beampatterns. Key advantages of numerical approaches are: efficient, high-resolution estimation of beampatterns, spatially dense predictions of near-field amplitudes, and the malleability of the underlying shape representations. A numerical approach that combines near-field predictions based on a finite-element formulation for harmonic solutions to the Helmholtz equation with a free-field projection based on the Kirchhoff integral to obtain estimates of the far-field beampattern is reviewed. This method has been used to predict physical beamforming mechanisms such as frequency-dependent beamforming with half-open resonance cavities in the noseleaf of horseshoe bats and beam narrowing through extension of the pinna aperture with skin folds in false vampire bats. The fine structure of biosonar beampatterns is discussed for the case of the Chinese noctule and methods for assessing the spatial information conveyed by beampatterns are demonstrated for the brown long-eared bat.
The acoustic field on the forehead of echolocating Atlantic bottlenose dolphins (Tursiops truncatus)
Authors: Au Whitlow W. L. , Houser Dorian S. , Finneran James J. , Lee Wu-Jung , Talmadge Lois A. , Moore Patrick W.
Published: September 2010

Arrays of up to six broadband suction cup hydrophones were placed on the forehead of two bottlenose dolphins to determine the location where the beam axis emerges and to examine how signals in the acoustic near-field relate to signals in the far-field. Four different array geometries were used; a linear one with hydrophones arranged along the midline of the forehead, and two around the front of the melon at 1.4 and 4.2 cm above the rostrum insertion, and one across the melon in certain locations not measured by other configurations. The beam axis was found to be close to the midline of the melon, approximately 5.4 cm above the rostrum insert for both animals. The signal path coincided with the low-density, low-velocity core of the melon; however, the data suggest that the signals are focused mainly by the air sacs. Slight asymmetry in the signals were found with higher amplitudes on the right side of the forehead. Although the signal waveform measured on the melon appeared distorted, when they are mathematically summed in the far-field, taking into account the relative time of arrival of the signals, the resultant waveform matched that measured by the hydrophone located at 1 m.
A model for the dynamics of ultrasound contrast agents in vivo
Authors: Qin Shengping , Ferrara Katherine W.
Published: September 2010

The Rayleigh-Plesset (RP) equation for a clean gas bubble in an incompressible and infinite liquid has previously been applied to approximately simulate the behavior of ultrasound contrast agents (UCA) in vivo, and extended RP equations have been proposed to account for the effects of the UCA shell or surrounding soft tissue. These models produce results that are consistent with experimental measurements for low acoustic pressure scenarios. For applications of UCAs in therapeutic medicine, the transmitted acoustic pulse can have a peak negative pressure (PNP) up to a few megapascals, resulting in discrepancies between measurements and predictions using these extended RP equations. Here, a model was developed to describe the dynamics of UCAs in vivo while taking account of the effects of liquid compressibility, the shell and the surrounding tissue. Liquid compressibility is approximated to first order and the shell is treated either as a Voigt viscoelastic solid or a Newtonian viscous liquid. Finite deformation of the shell and tissue is derived. Dynamics of UCAs with a shell of lipid, polymer, albumin and liquid are investigated for typical therapeutic ultrasound pulses. The effects of liquid compressibility and shell and tissue parameters are analyzed.
Stereotypic vocalizations in harvest mice (Reithrodontomys): Harmonic structure contains prominent and distinctive audible, ultrasonic, and non-linear elements
Authors: Miller Jacqueline R. , Engstrom Mark D.
Published: September 2010

Reports of audible vocalizations are rare in adult muroid rodents, animals generally very small in body size and under strong predation pressure. By contrast, communication using high, often ultrasonic vocal frequencies is relatively common. There are anecdotal reports of audible vocalizations for some harvest mice (genus Reithrodontomys), however none have been recorded or analyzed. Several species of harvest mice are studied, representing the subgenera Reithrodontomys (R. fulvescens, R. sumichrasti) and Aporodon (R. creper, R. mexicanus, R. spp.), as part of a larger phylogenetic analysis of stereotypical vocal communication. Only R. mexicanus produced stereotyped vocalizations on a regular basis. Acoustic signals of R. mexicanus contain prominent harmonics bridging both the audible and ultrasonic range, with evidence of non-linear distribution of energy within and between notes of an individual call. Harmonic emphasis varies, making the carrier frequency difficult to locate. These Reithrodontomys vocalizations are compared with members of their phylogenetic sister group Onychomys+Peromyscus, genera whose stereotypic calls exclusively occupy the audible or ultrasonic spectrum, respectively. It is hypothesized that the stereotypic signals of harvest mice represent announcement calls. Given the number of anecdotal reports of stereotyped 1, 2, and 3-note calls among Reithrodontomys species, further interspecific comparisons are warranted.
Noise prediction of a subsonic turbulent round jet using the lattice-Boltzmann method
Authors: Lew Phoi-Tack , Mongeau Luc , Lyrintzis Anastasios
Published: September 2010

The lattice-Boltzmann method (LBM) was used to study the far-field noise generated from a Mach, Mj=0.4, unheated turbulent axisymmetric jet. A commercial code based on the LBM kernel was used to simulate the turbulent flow exhausting from a pipe which is 10 jet radii in length. Near-field flow results such as jet centerline velocity decay rates and turbulence intensities were in agreement with experimental results and results from comparable LES studies. The predicted far field sound pressure levels were within 2 dB from published experimental results. Weak unphysical tones were present at high frequency in the computed radiated sound pressure spectra. These tones are believed to be due to spurious sound wave reflections at boundaries between regions of varying voxel resolution. These “VR tones” did not appear to bias the underlying broadband noise spectrum, and they did not affect the overall levels significantly. The LBM appears to be a viable approach, comparable in accuracy to large eddy simulations, for the problem considered. The main advantages of this approach over Navier–Stokes based finite difference schemes may be a reduced computational cost, ease of including the nozzle in the computational domain, and ease of investigating nozzles with complex shapes.
Evaluation of feedback reduction techniques in hearing aids based on physical performance measures
Authors: Spriet Ann , Moonen Marc , Wouters Jan
Published: September 2010

This paper presents a physical evaluation of four feedback cancellation techniques in commercial hearing aids and two implementations of a recently developed feedback cancellation algorithm. Based on physical measures for detecting instability, oscillations and distortion, three performance aspects were measured: 1) the added stable gain compared to the hearing aid operating without feedback reduction for white noise as well as for spectrally colored input signals in two static acoustic conditions, 2) the amount of feedback, oscillations and distortion at gain values below the maximum stable gain, 3) the ability to track feedback path changes. Added stable gains between 3 dB and 26 dB were identified. Five of the six techniques achieve worse feedback reduction for a tonal opera input signal than for a speech input signal. Preventing the feedback canceller to drift away from an initial feedback path measurement results in improved performance for tonal signals at the expense of a worse feedback reduction in the acoustic conditions that differ from the condition for which the initialization was performed, as well as a worse tracking of feedback path changes. Repeated measures indicated that the reproducibility of the test set-up is crucial, in particular when the hearing aid operates close to instability.
Analyzing phonetic confusions using formal concept analysis
Authors: Peláez-Moreno C. , García-Moral A. I. , Valverde-Albacete F. J.
Published: September 2010

Confusion matrices have been used as a tool for the analysis of speech perception or human speech recognition (HSR) for decades. However, they are rarely employed in automatic speech recognition (ASR) mainly due to the lack of a systematic procedure for their exploration. The generalization of formal concept analysis employed in this paper provides a conceptual interpretation of confusion matrices that enables the analysis of the structure of confusions for both human and machine performances. Generalized formal concept analysis transforms confusion matrices into ordered lattices of confusion events, supporting classic results in HSR that identify a hierarchy of virtual articulatory-acoustic channels. Translating this technique into ASR, a detailed map of the relationships among the speech units employed in the system can be traced to make different sources of confusions apparent: the influence of the lexicon, segmentation errors, dialectal variations or limitations of the feature extraction procedures, among others.
Diffraction from the edge of a thin elastic half plane and implications for panel measurements
Authors: Smith John D.
Published: September 2010

Solutions for the diffraction of a plane wave from the edge of a semi-infinite, thin elastic plate are presented. A thin plate formulation that takes into account the coupling into both symmetric and antisymmetric waves on the plate is used. The symmetric contributions are found to be small for steel in water but can be significant for plastic plates. Expansions in terms of the fluid loading parameter are used in the far field of the edge to explore the effect of the diffraction from a single edge on transmission measurements. Examples for steel and polymethylmethacrylate in water are presented.
Masking release and the contribution of obstruent consonants on speech recognition in noise by cochlear implant users
Authors: Li Ning , Loizou Philipos C.
Published: September 2010

Cochlear implant (CI) users are unable to receive masking release and the reasons are unclear. The present study examines the hypothesis that when listening to speech in fluctuating maskers, CI users cannot fuse the pieces of the message over temporal gaps because they are not able to perceive reliably the information carried by obstruent consonants (e.g., stops). To test this hypothesis, CI users were presented with sentences containing clean obstruent segments, but corrupted sonorant segments (e.g., vowels). Results indicated that CI users received masking release at low signal-to-noise ratio levels. Experiment 2 assessed the contribution of acoustic landmarks alone by presenting to CI users noise-corrupted stimuli which had clearly marked vowel/consonant boundaries, but lacking clean obstruent consonant information. These stimuli were created using noise-corrupted envelopes processed using logarithmic compression during sonorant segments and a weakly-compressive mapping function during obstruent segments. Results indicated that the use of segment-dependent compression yielded significant improvements in intelligibility, but no masking release. The results from these experiments suggest that in order for CI users to receive masking release, it is necessary to perceive reliably not only the presence and location of acoustic landmarks (i.e., vowel/consonant boundaries) but also the information carried by obstruent consonants.
Experimental demonstration of the utility of pressure sensitivity kernels in time-reversal
Authors: Raghukumar Kaustubha , Cornuelle Bruce D. , Hodgkiss William S. , Kuperman William A.
Published: September 2010

Pressure sensitivity kernels were recently applied to time-reversal acoustics in an attempt to explain the enhanced stability of the time-reversal focal spot [Raghukumar et al., J. Acoust. Soc. Am. 124, 98–112 (2008)]. The theoretical framework developed was also used to derive optimized source functions, closely related to the inverse filter. The use of these optimized source functions results in an inverse filter-like focal spot which is more robust to medium sound speed fluctuations than both time-reversal and the inverse filter. In this paper the theory is applied to experimental data gathered during the Focused Acoustic Fields experiment, conducted in 2005, north of Elba Island in Italy. Sensitivity kernels are calculated using a range-independent sound-speed profile, for a geometry identical to that used in the experiment, and path sensitivities are identified with observed arrivals. The validity of the kernels in tracking time-evolving Green’s functions is studied, along with limitations that result from a linearized analysis. An internal wave model is used to generate an ensemble of sound speed profiles, which are then used along with the calculated sensitivity kernels to derive optimized source functions. Focal spots obtained using the observed Green’s functions with these optimized source functions are then compared to those obtained using time-reversal and the inverse-filter. It is shown that these functions are able to provide a focal spot superior to time-reversal while being more robust to sound speed fluctuations than the inverse filter or time-reversal.
Language-specific realizations of syllable structure and vowel-to-vowel coarticulation
Authors: Mok P. K. Peggy
Published: September 2010

This paper investigates the effects of syllable structure on vowel-to-vowel (V-to-V) coarticulation using Thai and English data. Languages differ in syllable complexity and their realizations of syllable structure. It was hypothesized that languages with complex syllable structure (English) would allow more V-to-V coarticulation than languages with simple syllable structure (Thai). Onset and coda consonants are different acoustically, articulatorily, typologically and perceptually. Onsets are generally ‘stronger’ and more stable than codas because they are longer, louder, and involve tighter articulatory constrictions. It was hypothesized that closed syllables (that end in a consonant C, i.e., VC#V) would allow more V-to-V coarticulation than open syllables (V#CV). /C1V1#C2V2/ and /C1V1C2#V2t/ sequences were recorded from six native speakers in Thai and six in English. First and second formant frequencies were measured. Results show that English allows more V-to-V coarticulation than Thai regardless of the intervocalic duration and vowel quality difference, but open and closed syllables only affect V-to-V coarticulation minimally. In addition to syllable structure, other possible factors contributing to the language difference in V-to-V coarticulation are discussed.
Phase-coherent communications without explicit phase tracking
Authors: Song H. C. , Hodgkiss W. S. , van Walree P. A.
Published: September 2010

Phase-coherent communications typically requires a reliable phase-tracking algorithm. An initial phase estimate with training symbols allows a receiver to compensate for a motion-induced Doppler shift. Following the training period, however, explicit phase tracking can be avoided in time reversal communications that has been implemented on a block-by-block basis to accommodate time-varying channels. This is accomplished by a smaller block size and adaptive channel estimation using previously detected symbols on a symbol-by-symbol basis. The proposed time reversal approach without explicit phase tracking is demonstrated using experimental data (12–20 kHz) in shallow water.
The psychomechanics of simulated sound sources: Material properties of impacted thin plates
Authors: McAdams Stephen , Roussarie Vincent , Chaigne Antoine , Giordano Bruno L.
Published: September 2010

Sounds convey information about the materials composing an object. Stimuli were synthesized using a computer model of impacted plates that varied their material properties: viscoelastic and thermoelastic damping and wave velocity (related to elasticity and mass density). The range of damping properties represented a continuum between materials with predominant viscoelastic and thermoelastic damping (glass and aluminum, respectively). The perceptual structure of the sounds was inferred from multidimensional scaling of dissimilarity judgments and from their categorization as glass or aluminum. Dissimilarity ratings revealed dimensions that were closely related to mechanical properties: a wave-velocity-related dimension associated with pitch and a damping-related dimension associated with timbre and duration. When asked to categorize sounds, however, listeners ignored the cues related to wave velocity and focused on cues related to damping. In both dissimilarity-rating and identification experiments, the results were independent of the material of the mallet striking the plate (rubber or wood). Listeners thus appear to select acoustical information that is reliable for a given perceptual task. Because the frequency changes responsible for detecting changes in wave velocity can also be due to changes in geometry, they are not as reliable for material identification as are damping cues.
Prosodic predictors of upcoming positive or negative content in spoken messages
Authors: Swerts Marc , Hirschberg Julia
Published: September 2010

This article examines potential prosodic predictors of emotional speech in utterances perceived as conveying that good or bad news is about to be delivered. Speakers were asked to call an experimental confederate to inform her about whether or not she had been given a job she had applied for. A perception study was then performed in which initial fragments of the recorded utterances, not containing any explicit lexical cues to emotional content, were presented to listeners who had to rate whether good or bad news would follow the utterance. The utterances were then examined to discover acoustic and prosodic features that distinguished between good and bad news. It was found that speakers in the production study were not simply reflecting their own positive or negative mood during the experiment, but rather appeared to be influenced by the valence of the positive or negative message they were preparing to deliver. Positive and negative utterances appeared to be judged differently with respect to a number of perceived attributes of the speakers’ voices (like sounding hesitant or nervous). These attributes correlated with a number of automatically obtained acoustic features.
Production of French vowels by American-English learners of French: Language experience, consonantal context, and the perception-production relationship
Authors: Levy Erika S. , Law Franzo F.
Published: September 2010

Second-language (L2) speech perception studies have demonstrated effects of language background and consonantal context on categorization and discrimination of vowels. The present study examined the effects of language experience and consonantal context on the production of Parisian French (PF) vowels by American English (AE) learners of French. Native AE speakers repeated PF vowels /i-y-u-œ-a/ in bilabial /bVp/ and alveolar /dVt/ contexts embedded in the phrase /raCVCa/. Three AE groups participated: speakers without French experience (NoExp), speakers with formal French experience (ModExp), and speakers with formal-plus-immersion experience (HiExp). Production accuracy was assessed by native PF listeners’ judgments and by acoustic analysis. PF listeners identified L2 learners’ productions more accurately when the learners had extensive language experience, although /y-u-œ/ by even HiExp speakers were frequently misidentified. A consonantal context effect was evident, including /u/ produced by ModExp misidentified more often in alveolar context than in bilabial, and /y/ misidentified more often in bilabial than in alveolar context, suggesting cross-language transfer of coarticulatory rules. Overall, groups distinguished front rounded /y/ from /u/ in production, but often in a non-native manner, e.g., producing /y/ as /uj/. Examination of perceptual data from the same individuals revealed a modest, yet complex, perception-production link for L2 vowels.
A micro-machined piezoelectric flexural-mode hydrophone with air backing: Benefit of air backing for enhancing sensitivity
Authors: Lee Haksue , Choi Sungjoon , Moon Wonkyu
Published: September 2010

A micro-machined underwater acoustic receiver that utilizes the flexural vibration mode of a silicon thin plate and piezoelectric transduction material was investigated. In particular, air was used as the backing material for the hydrophone in order to improve sensitivity in the audible frequency range. To evaluate the effects of air backing on receiving sensitivity, a transduction model incorporating mechanical/electrical/acoustical design parameters was used in designing a piezoelectric micro-machined hydrophone. The sensitivity and displacement responses of the sensor were simulated using the model for air backing and water backing cases, and the benefit of using air backing to enhance sensitivity was confirmed. The micro-machined piezoelectric transducer was fabricated, assembled in the shape of a hydrophone, and tested to ascertain its characteristics as an underwater sensor. These characteristics, such as frequency response and sensitivity, were measured and compared with the simulated results.