bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamic Evolution and Hydrocarbon Accumulation in the Dabashan Foreland Thrust Belt, China
Authors: Jianhui ZENG , Kai GUO , Kun TIAN , Tianwu XU
Published: August 2012

There are two plays in the Dabashan foreland tectonic belt: the upper and the lower plays. The lower play experienced one sedimentary hydrodynamic stage, two burial hydrodynamic stages, two tectonic hydrodynamic stages and two infiltration hydrodynamic stages from the Sinian to the Cenozoic, while the upper play had one sedimentary hydrodynamic stage, one burial hydrodynamic stage, two tectonic hydrodynamic stages and one infiltration hydrodynamic stage from the Permian to the Cenozoic. Extensive flows of both sedimentary water, including hydrocarbons, and deep mantle fluid occurred in the Chengkou faults during collision orogeny in the Middle‐Late Triassic Indosinian orogeny, and fluid flow was complicated during intracontinental orogeny in the Middle‐Late Jurassic. In addition to these movements, infiltration and movement of meteoric water took place in the Chengkou faults, whereas in the covering‐strata decollement tectonic belt, extensive sedimentary water flow (including hydrocarbons) occurred mainly in the Zhenba and Pingba faults. During the stage of rapid uplift and exhumation from the Cretaceous to the Cenozoic, the fluid flow was characterized mainly by infiltration of meteoric water and gravity‐induced flow caused by altitude difference, whereas sedimentary water flow caused by tectonic processes was relatively less significant. Sedimentary water flow was more significant to the lower play in hydrocarbon migration and accumulation during collision orogeny in the Middle‐Late Triassic Indosinian orogeny, but its influence is relatively slight on the upper play. On one hand, hydrodynamics during intracontinental orogeny in the Middle‐Late Jurassic adjusted, reformed or oven destroyed oil reservoirs in the lower play; on the other hand, it drove large amounts of hydrocarbons to migrate laterally and vertically and is favorable for hydrocarbon accumulation. Infiltration hydrodynamics mainly adjusted and destroyed oil reservoirs from the Cretaceous to the Cenozoic.
Bicarbonate Daily Variations in a Karst River: the Carbon Sink Effect of Subaquatic Vegetation Photosynthesis
Authors: Cheng ZHANG , Jinliang WANG , Junbing PU , Jun YAN
Published: August 2012

Using the Guancun River, an underground stream‐fed river, in Rong'an County of Guangxi, China as a case study, the daily biochemical cycle was examined in this paper based on the data collected a weeklong via high resolution data logger monitoring and high‐frequency sampling. Furthermore, the loss of inorganic carbon along its flow path was estimated. Results show that chemical components of the groundwater input are quite stable, showing little change extent; while all of the chemical parameters from two downstream monitoring stations show diel variation over the monitoring period, suggesting that plant activity in the river has a strong influence on water chemistry of the river. The comparison of the input fluxes from the groundwater with the output fluxes of HCO–3 estimated at the downstream monitoring station during the high‐frequency sampling period shows a strong decrease of HCO–3, indicating that the river is losing inorganic carbon along its flow path. The loss is estimated to be about 1,152 mmol/day/m of HCO–3 which represent about 94.9 kg/day of inorganic carbon along the 1,350 m section of the Guancun River. It means that HCO–3 entering the river from karst underground stream was either consumed by plants or trapped in the authigenic calcite and thus constitutes a natural sink of carbon for the Guancun karst system.
Quantitative Zoning Assessment of Crustal Stability Along the Yunnan–Tibet Railway Line, Western China
Authors: Yongshuang ZHANG , Xin YAO , Daogong HU , Changbao GUO , Tanyu XIONG
Published: August 2012

The planned Yunnan–Tibet railway goes through the northwest of Yunnan Province and the southeast of the Tibet Autonomous Region. Because of its location near the collision belt of the Eurasian and Indian plates, complex engineering geological conditions and difficult engineering geological problems are encountered. The study is aimed at making the zoning assessment of crustal stability along the railway line so as to provide a better base for its construction, especially its line selection. For this purpose, the following seven influencing factors of crustal stability were selected and quantified by grading and scoring: active fault, seismic activity, geo‐stress field, geo‐strain field, geothermal field, geo‐hazard, and lithologic character. Of these factors, the active fault, seismic activity and geo‐hazard are the three most prominent factors influencing the railway construction. Along the railway line there are 1731703 calculation units to be divided. The zoning assessment calculation was completed by ArcGIS‐based information fusion method. The assessment results aid railway line selection and show that there are 10 stable sectors, 28 relatively stable sectors, 23 relatively unstable sectors, and 20 unstable sectors along the Yunnan–Tibet railway line.
Multi‐scale Decomposition of Co‐seismic Deformation from High Resolution DEMs: a Case Study of the 2004 Mid‐Niigata Earthquake
Authors: Yu ZHAO , Kazuo KONAGAI , Tomohiro FUJITA
Published: August 2012

Decomposing co‐seismic deformation is an immediate need for researchers who are interested in earthquake inversion analysis and geo‐hazard mapping. However, conventional InSAR or digital elevation models (DEMs) imagery analyses only provide the displacement in the Line‐of‐Sight (LOS) direction or elevation changes. The 2004 Mid‐Niigata earthquake in Japan provides lessons on how to decompose co‐seismic deformation from two sets of DEMs. If three adjacent points undergo a rigid‐body‐translation movement, their co‐seismic deformation can be decomposed by solving simultaneous equations. Although this method has been successfully used to discuss tectonic deformations, the algorithm needed improvement and a more rigorous algorithm, including a new definition of nominal plane, DEMs comparability improvement and matrix condition check is provided. Even with these procedures, the obtained decomposed displacement often showed remarkable scatter prompting the use of the moving average method, which was used to determine both tectonic and localized displacement characteristics. A cut‐off window and a pair of band‐pass windows were selected according to the regional geology and construction activities to ease the tectonic and localized displacement calculations, respectively. The displacement field of the tectonic scale shows two major clusters of large lateral components, and coincidently major visible landslides were found mostly within them. The localized displacement helps to reveal hidden landslides in the target area. As far as the Kizawa hamlet is concerned, the obtained vectors show down‐slope movements, which are consistent with the observed traces of dislocations that were found in the Kizawa tunnel and irrigation wells. The method proposed has great potential to be applied to understanding post‐earthquake rehabilitation in other areas.
Landslide Susceptibility Mapping and Evaluation along a River Valley in China
Authors: Yanrong LI , AYDIN Adnan , Xiqiong XIANG , Nengpan JU , Jianjun ZHAO , OZBEK Ahmet
Published: August 2012

Landslide susceptibility evaluation at regional scale is commonly performed based dominantly on the analysis of geological and geomorphological conditions of historical landslide cases. The main content of this type of evaluation covers identifying key casual factors, their critical groupings and relative importance. The present study demonstrates an application of the above concept to a 90 km long segment of Jinshajiang River valley in China. Correlations of landslide occurrence with potential causative factors are derived according to interpretation of field investigation. Lithology, orientation of bedding planes, slope angle, stream action, rainfall and earthquake intensity are selectively recognized as identifiable/measurable causative factors to establish a factor domain. The membership grades, for field values of quantitative factors, to the susceptibility classes are determined based on the construction of fuzzy sets, while those for descriptive factors are assigned from a fuzzy score table. The analytic hierarchy process (AHP) is adopted for assigning weights to each individual factor. Subsequently, the evaluation is implemented in a GIS program IDRISI, where four classes of landslide susceptibility are identified and delineated in the subject area. The approach described in the present paper showed consistence with the nature and availability of data for evaluating landslide susceptibility at regional scale. The methodology presented can be effectively employed by relevant authorities to identify risky areas for dislocating major infrastructural project, and develop management strategies for land use.
Nelumbonaceae: Systematic position and species diversification revealed by the complete chloroplast genome
Authors: XUE Jian‐Hua , DONG Wen‐Pan , CHENG Tao , ZHOU Shi‐Liang
Published: August 2012

Abstract  Nelumbonaceae is a morphologically unique family of angiosperms and was traditionally placed in Nymphaeales; more recently, it was placed in Proteales based on molecular data, or in an order of its own, Nelumbonales. To determine the systematic position of the family and to date the divergence time of the family and the divergence time of its two intercontinentally disjunct species, we sequenced the entire chloroplast genome of Nelumbo lutea and most of the chloroplast genes of N. nucifera. We carried out phylogenetic and molecular dating analyses of the two species and representatives of 47 other plant families, representing the major lineages of angiosperms, using 83 plastid genes. The N. lutea genome was 163 510 bp long, with a total of 130 coding genes and an overall GC content of 38%. No significant structural differences among the genomes of N. lutea, Nymphaea alba, and Platanus occidentalis were observed. The phylogenetic relationships based on the 83 plastid genes revealed a close relationship between Nelumbonaceae and Platanaceae. The divergence times were estimated to be 109 Ma between the two families and 1.5 Ma between the two Nelumbo species. The estimated time was only slightly longer than the age of known Nelumbo fossils, suggesting morphological stasis within Nelumbonaceae. We conclude that Nelumbonaceae holds a position in or close to Proteales. We further conclude that the two species of Nelumbo diverged recently from a common ancestor and do not represent ancient relicts on different continents.
Spotted Fever Group – Rickettsiae in the Tyrols: Evidence by Seroepidemiology and PCR
Authors: Sonnleitner S. T. , Simeoni J. , Lang S. , Dobler G. , Speck S. , Zelger R. , Schennach H. , Lass‐Flörl C. , Walder G.
Published: August 2012

The aim of our study was to assess the occurrence of Rickettsia in the inner‐alpine valleys of the Eastern Alps and to determine the amount of seroreaction among the local human population. Ticks were investigated by PCR and the percentage of seropositives was determined among local blood donors by an in‐house immunofluorescence assay. The local cut‐off titre for screening of IgG was set at 1 : 128 with a well‐characterised low‐risk collective according to WHO‐guidelines. Positive sera were confirmed by independent re‐testing. Rickettsia is present in ticks north and south of the continental divide. Of 259 ticks investigated, 12.4% are positive for Rickettsia. Of over 1200 blood donors tested so far, 7.7% bear IgG at a titre of 1 : 128 or higher against R. helvetica. R. helvetica is present in the study area, causes immunoreaction among local residents and is associated with anamnestic erythema. Furthermore, screening with a second Spotted Fever Group Rickettsia indicates that significant parts of the Tyrolean population are exposed to a Rickettsia other than R. helvetica.
Case–control study of high‐speed exercise history ofThoroughbred andQuarterHorse racehorses that died related to a complete scapular fracture
Authors: Vallance S. A. , Entwistle R. C. , Hitchens P. L. , Gardner I. A. , Stover S. M.
Published: August 2012

Reasons for performing study:

Identification of exercise history patterns that are related to catastrophic scapular fracture will facilitate prevention of racehorse fatalities.

Objectives:

To determine if exercise patterns are associated with scapular fracture inThoroughbred (TB) andQuarterHorse (QH) racehorses.

Methods:

High‐speed exercise histories for 65TBand 26QHracehorses that had a complete scapular fracture (cases) and 2 matched control racehorses were retrospectively studied. Exercise variables were created from lifetime race and official timed workout reports. Associations between exercise variables and scapular fracture were investigated using conditional logistic regression.

Results:

Thoroughbreds with a scapular fracture had a greater number of workouts, events (combined works and races), and mean event distances thanQHs with a scapular fracture. Quarter Horses worked less frequently and accumulated distance at a lower rate thanTBs. Breed differences were not found for career race number or length, time between races or lay‐up variables for horses with ≥1 lay‐up. For both breeds, cases had fewer events, lower recent accumulated distance and fewer active days in training than controls; however, a subset ofTBcases with >10 events since lay‐up had a longer active career than controls. ForQHs that had a lay‐up, total and mean lay‐up times were greater for cases than controls. Multivariable models revealed that odds ratios (OR) of scapular fracture were greater forTBs that had not yet raced (OR= 23.19; 95% confidence interval (CI) 3.03–177.38) and lower forQHs with more events (OR= 0.71; 95% CI 0.54–0.94).

Conclusions and clinical relevance:

Racehorses that are in early high‐speed training but behind that of their training cohort should be examined for signs of scapular stress remodelling. Quarter Horses that had a prolonged lay‐up andTBs that have endured high‐speed training for a longer duration than that of their training cohort also were at greater risk.
Socioeconomic factors and childhood overweight in Europe: results from the multi‐centre IDEFICS study
Authors: Bammann K. , Gwozdz W. , Lanfer A. , Barba G. , De Henauw S. , Eiben G. , Fernandez‐Alvira J.M. , Kovács E. , Lissner L. , Moreno L.A. , Tornaritis M. , Veidebaum T. , Pigeot I. ,   the IDEFICS Consortium
Published: August 2012

What is already known about this subject

Overweight and obesity can be linked to different parental socioeconomic factors already in very young children.

In Western developed countries, the association of childhood overweight and obesity and parental socioeconomic status shows a negative gradient.

Ambiguous results have been obtained regarding the association between socioeconomic factors and childhood overweight and obesity in different countries and over time.

What this study adds

European regions show heterogeneous associations between socioeconomic factors and overweight and obesity in a multi‐centre study with highly standardized study protoco.

The strength of association between SES and overweight and obesity varies across European regions.

In our study, the SES gradient is correlated with the regional mean income and the country‐specific Human development index indicating a strong influence not only of the family but also of region and country on the overweight and obesity prevalence.

Objective

To assess the association between different macro‐ and micro‐level socioeconomic factors and childhood overweight.

Methods

Data from the IDEFICS baseline survey is used to investigate the cross‐sectional association between socioeconomic factors, like socioeconomic status (SES), and the prevalence of childhood overweight. Differences and similarities regarding this relationship in eight European regions (located in Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden) are explored. 11 994 children (50.9% boys, 49.1% girls) and their parents were included in the analyses.

Results

In five of the eight investigated regions (in Belgium, Estonia, Germany, Spain and Sweden), the prevalence of childhood overweight followed an inverse SES gradient. In the other three regions (in Cyprus, Hungary and Italy), no association between SES and childhood overweight was found. The SES‐overweight association in a region was best explained by the country‐specific human development index and the centre‐specific mean income. For the investigated association between other socioeconomic factors and overweight, no clear pattern could be found in the different regions.

Conclusion

The association between socioeconomic factors and childhood overweight was shown to be heterogeneous across different European regions. Further research on nationwide European data is needed to confirm the results and to identify target groups for prevention.
The appropriateness of opt‐out consent for monitoring childhood obesity in Australia
Authors: Lacy K. , Kremer P. , de Silva‐Sanigorski A. , Allender S. , Leslie E. , Jones L. , Fornaro S. , Swinburn B.
Published: August 2012

Childhood obesity monitoring is a fundamental component of obesity prevention but is poorly done in Australia. Monitoring obesity prevalence in children provides important population health data that can be used to track trends over time, identify areas at greatest risk of obesity, determine the effectiveness of interventions and policies, raise awareness and stimulate action. High participation rates are essential for effective monitoring because these provide more representative data. Passive (‘opt‐out’) consent has been shown to provide high participation rates in international childhood obesity monitoring programs and in a recent Australian federal initiative monitoring early child development. A federal initiative structured like existing child development monitoring programs, but with the authority to collect height and weight measurements using opt‐out consent, is recommended to monitor rates of childhood obesity in Australia.
Postexercise hypotension and sustained postexercise vasodilatation: what happens after we exercise?
Authors: Halliwill John R. , Buck Tahisha M. , Lacewell Alisha N. , Romero Steven A.
Published: August 2012

New findings

What is the topic for this review?

During the exercise recovery period, the combination of centrally mediated decreases in sympathetic nerve activity with a reduced signal transduction from sympathetic nerve activation into vasoconstriction, as well as local vasodilator mechanisms, contributes to the fall in arterial blood pressure seen after exercise.

What advances does it highlight?

Important findings from recent studies include the recognition that skeletal muscle afferents may play a primary role in postexercise resetting of the baroreflex via discrete receptor changes within the nucleus tractus solitarii and that sustained postexercise vasodilatation of the previously active skeletal muscle is primarily the result of histamine H1 and H2 receptor activation.

A single bout of aerobic exercise produces a postexercise hypotension associated with a sustained postexercise vasodilatation of the previously exercised muscle. Work over the last few years has determined key pathways for the obligatory components of postexercise hypotension and sustained postexercise vasodilatation and points the way to possible benefits that may result from these robust responses. During the exercise recovery period, the combination of centrally mediated decreases in sympathetic nerve activity with a reduced signal transduction from sympathetic nerve activation into vasoconstriction, as well as local vasodilator mechanisms, contributes to the fall in arterial blood pressure seen after exercise. Important findings from recent studies include the recognition that skeletal muscle afferents may play a primary role in postexercise resetting of the baroreflex via discrete receptor changes within the nucleus tractus solitarii and that sustained postexercise vasodilatation of the previously active skeletal muscle is primarily the result of histamine H1 and H2 receptor activation. Future research directions include further exploration of the potential benefits of these changes in the longer term adaptations associated with exercise training, as well as investigation of how the recovery from exercise may provide windows of opportunity for targeted interventions in patients with hypertension and diabetes.
Peripheral chemoreceptors mediate training‐induced plasticity in paraventricular nucleus pre‐autonomic oxytocinergic neurons
Authors: Cruz Josiane C. , Cavalleri Marina T. , Ceroni Alexandre , Michelini Lisete C.
Published: August 2012

New findings

What is the central question of this study?

This study addresses the role of carotid chemoreceptors in mediating exercise training‐induced plasticity in the paraventricular nucleus and changes in heart rate and blood pressure in normotensive and hypertensive rats.

What is the main finding and its importance?

The present data show that peripheral chemoreceptor afferent signalling is crucial to drive the plasticity/activity of paraventricular nucleus oxytocinergic pre‐autonomic neurons, thus mediating training‐induced resting bradycardia in normotensive and hypertensive rats and pressure reduction in hypertensive animals.

We showed previously that sino‐aortic denervation prevented training‐induced plasticity in pre‐autonomic oxytocinergic neurons and blocked the beneficial effects of training. In this study, we investigate the combined effect of training and removal of specific chemoreceptor afferents on both cardiovascular parameters and oxytocin (OT) gene and protein expression within the hypothalamic paraventricular nucleus (PVN). Wistar rats and spontaneously hypertensive rats (SHRs) underwent carotid body denervation or sham surgery and were trained or kept sedentary for 3 months. After haemodynamic measurements at rest, rats were anaesthetized for brain perfusion. Fresh (perfused with PBS) and fixed brains (perfused with 4% paraformaldehyde) were processed for PVN OT mRNA (real‐time PCR) and OT immunoreactivity within PVN subnuclei. In sham‐operated rats, training improved treadmill performance and reduced resting heart rate (Wistar, −8%; SHRs, −10%), with a reduction in blood pressure only in SHRs (−8%). Training was accompanied by increased PVN OT mRNA expression (twofold increase in sham‐operated SHRs) and peptide density in the posterior, ventromedial and dorsal cap PVN subnuclei (on average 70% increase in both strains), with significant correlations between OT content and training‐induced resting bradycardia in sham‐operated groups. Carotid body denervation did not interfere with the performance gain, abolished chemoreflex activation (without changing baroreflex control) and blocked training‐induced cardiovascular adaptations and training‐induced changes in PVN OT content in both strains. After carotid body denervation, there was no correlation between OT mRNA or OT immunoractivity and resting heart rate. The chronic absence of chemoreceptor inputs uncovers an unknown role of chemoreceptor signalling in driving the plasticity/activity of PVN oxytocinergic pre‐autonomic neurons, thus mediating training‐induced cardiovascular adaptive responses.
Influence of film thickness and deposition rate on surface quality of polyparylene coatings
Authors: Schamberger Florian , Ziegler Astrid , Franz Gerhard
Published: August 2012

Polyparylene is a polymer with outstanding properties when compared to other synthetics. Therefore, chemical vapor deposition of polyparylene is making inroads in several technical fields. Even applications demanding tight requirements on coating quality, like gate dielectrics for the semiconductor industry and semipermeable layers for drug eluting implants in medical science, are coming within its purview. In this paper, the impact of film thickness and deposition rate of the polyparylene CVD process on surface parameters like roughness and pinhole density is investigated. Surface roughness and pinhole density were monitored by atomic force microscopy (AFM) measurement. Furthermore, the influence of the pinhole density on tunneling current and breakdown voltage of the deposited layers is also investigated. The results obtained are used to establish an easy method to estimate the pinhole density by electrical measurement rather than the AFM method, which is not only time consuming but also limited to small flat areas. To deposit very thin layers below a thickness of 1 μm, conventional coating techniques for polyparylene have been replaced by a completely new method that features a steep slew rate for the deposition rate. The new coating method is superior to the well-known Gorham method with respect to the temperature dependent deposition rate, which makes the coating of very thin layers impossible.
Binding and unbinding the auditory and visual streams in the McGurk effect
Authors: Nahorna Olha , Berthommier Frédéric , Schwartz Jean-Luc
Published: August 2012

Subjects presented with coherent auditory and visual streams generally fuse them into a single percept. This results in enhanced intelligibility in noise, or in visual modification of the auditory percept in the McGurk effect. It is classically considered that processing is done independently in the auditory and visual systems before interaction occurs at a certain representational stage, resulting in an integrated percept. However, some behavioral and neurophysiological data suggest the existence of a two-stage process. A first stage would involve binding together the appropriate pieces of audio and video information before fusion per se in a second stage. Then it should be possible to design experiments leading to unbinding. It is shown here that if a given McGurk stimulus is preceded by an incoherent audiovisual context, the amount of McGurk effect is largely reduced. Various kinds of incoherent contexts (acoustic syllables dubbed on video sentences or phonetic or temporal modifications of the acoustic content of a regular sequence of audiovisual syllables) can significantly reduce the McGurk effect even when they are short (less than 4 s). The data are interpreted in the framework of a two-stage “binding and fusion” model for audiovisual speech perception.
Loudness perception of low tones undergoing partial masking by higher tones in orchestral music in concert halls
Authors: Nishihara Noriko , Hidaka Takayuki
Published: August 2012

Objective acoustical parameters for halls are often measured in 1-octave bands with mid-frequencies from 125 to 4000 Hz. In reality, the frequency range of musical instruments is much wider than that, and the fundamentals of the lower notes of bass instruments are contained in 31.5 or 63 Hz bands. Overtones of fundamentals in these bands fall in 125 Hz band. This report presents subjective experiments designed to determine to what extent the overtones in 125 Hz band and higher bands influence the loudness sensation of the components in 63 Hz band. In the experiments, the 125 Hz and higher components of the musical tone are used to act as a masker against the lower component used as a maskee. The threshold of the difference between G(125 Hz) and G(lower band) that just enables one to hear the fundamental tones in the lower band is determined. Masked loudness of 63 Hz sinusoidal tone caused by partial masking noise with higher frequencies was determined based on a similar procedure to the masked loudness-matching function. The result indicates that the difference in loudness of low tone will not be noticeable even if G changed by ±2.5 to ±3 dB, at least when there are other accompanying instruments.
Conversational quality evaluation of artificial bandwidth extension of telephone speech
Authors: Pulakka Hannu , Laaksonen Laura , Yrttiaho Santeri , Myllylä Ville , Alku Paavo
Published: August 2012

Artificial bandwidth extension methods have been developed to improve the quality and intelligibility of narrowband telephone speech and to reduce the difference with wideband speech. Such methods have commonly been evaluated with objective measures or subjective listening-only tests, but conversational evaluations have been rare. This article presents a conversational evaluation of two methods for the artificial bandwidth extension of telephone speech. Bandwidth-extended narrowband speech is compared with narrowband and wideband speech in a test setting including a simulated telephone connection, realistic conversation tasks, and various background noise conditions. The responses of the subjects indicate that speech processed with one of the methods is preferred to narrowband speech in noise, but wideband speech is superior to both narrowband and bandwidth-extended speech. Bandwidth extension was found to be beneficial for telephone conversation in noisy listening conditions.
Semi-coherent time of arrival estimation using regression
Authors: Apartsin Alexander , Cooper Leon N. , Intrator Nathan
Published: August 2012

Time of arrival (ToA) estimation is essential for many types of remote sensing applications including radar, sonar, and underground exploration. The standard method for ToA estimation employs a matched filter for computing the maximum likelihood estimator (MLE) for ToA. The accuracy of the MLE decreases rapidly whenever the amount of noise in a received signal rises above a certain threshold. This well-known threshold effect is unavoidable in several important applications due to various limitations on the power and the spectrum of a narrowband source pulse. A measurement performed in the presence of the threshold effect employs a receiver which operates in the semi-coherent state. Therefore, the conventional methods assuming a coherent state receiver should be adapted to the semi-coherent case. In this paper, a biosonar-inspired method for the semi-coherent ToA estimation is described. The method abandons the exploration of an echo signal by a single matched filter in favor of the analysis by multiple phase-shifted unmatched filters. Each phase-shifted unmatched filter gives rise to a biased ToA estimator. The described method uses regression for combining these estimators into a single unbiased ToA estimator that outperform the MLE in the presence of the threshold effect.
Seasonal and geographical patterns of fin whale song in the western North Atlantic Ocean
Authors: Morano Janelle L. , Salisbury Daniel P. , Rice Aaron N. , Conklin Karah L. , Falk Keri L. , Clark Christopher W.
Published: August 2012

Male fin whales, Balaenoptera physalus, produce a song consisting of 20 Hz notes at regularly spaced time intervals. Previous studies identified regional differences in fin whale internote intervals (INI), but seasonal changes within populations have not been closely examined. To understand the patterns of fin whale song in the western North Atlantic, the seasonal abundance and acoustic features of fin whale song are measured from two years of archival passive acoustic recordings at two representative locations: Massachusetts Bay and New York Bight. Fin whale 20 Hz notes are detected on 99% of recorded days. In both regions, INI varies significantly throughout the year as two distinct periods: a “short-INI” season in September–January (9.6 s) and a “long-INI” season in March–May (15.1 s). February and June–August are transitional-INI months, with higher variability. Note abundance decreases with increasing INI, where note abundance is significantly lower in April–August than in September–January. Short-INI and high note abundance correspond to the fin whale reproductive season. The temporal variability of INI may be a mechanism by which fin whale individuals encode and communicate a variety of behaviorally relevant information.
Comparison of speaking fundamental frequency in English and Mandarin
Authors: Keating Patricia , Kuo Grace
Published: August 2012

To determine if the speaking fundamental frequency (F0) profiles of English and Mandarin differ, a variety of voice samples from male and female speakers were compared. The two languages’ F0 profiles were sometimes found to differ, but these differences depended on the particular speech samples being compared. Most notably, the physiological F0 ranges of the speakers, determined from tone sweeps, hardly differed between the two languages, indicating that the English and Mandarin speakers’ voices are comparable. Their use of F0 in single-word utterances was, however, quite different, with the Mandarin speakers having higher maximums and means, and larger ranges, even when only the Mandarin high falling tone was compared with English. In contrast, for a prose passage, the two languages were more similar, differing only in the mean F0, Mandarin again being higher. The study thus contributes to the growing literature showing that languages can differ in their F0 profile, but highlights the fact that the choice of speech materials to compare can be critical.
On the estimation of dynamic mass density of random composites
Authors: Jin Congrui
Published: August 2012

The dynamic effective mass density and bulk modulus of an inhomogeneous medium at low frequency limit are discussed. Random configurations in a variety of two-dimensional physical contexts are considered. In each case, effective dynamic mass density and bulk modulus are calculated based on eigenmode matching theory. The results agree with those provided by Martin et al. [J. Acoust. Soc. Am. 128, 571–577 (2010)] obtained from effective wavenumber method.
High-frequency auditory filter shape for the Atlantic bottlenose dolphin
Authors: Lemonds David W. , Au Whitlow W. L. , Vlachos Stephanie A. , Nachtigall Paul E.
Published: August 2012

High-frequency auditory filter shapes of an Atlantic bottlenose dolphin (Tursiops truncatus) were measured using a notched noise masking source centered on pure tone signals at frequencies of 40, 60, 80 and 100 kHz. A dolphin was trained to swim into a hoop station facing the noise/signal transducer located at a distance of 2 m. The dolphin’s masked threshold was determined using an up-down staircase method as the width of the notched noise was randomly varied from 0, 0.2, 04, 0.6, and 0.8 times the test tone frequency. The masked threshold decreased as the width of the notched increased and less noise fell within the auditory filter associated with the test tone. The auditory filter shapes were approximated by fitting a roex (p,rr) function to the masked threshold results. A constant-Q value of 8.4 modeled the results within the frequency range of 40 to 100 kHz relatively well. However, between 60 and 100 kHz, the 3 dB bandwidth was relatively similar between 9.5 and 10 kHz, indicating a constant-bandwidth system in this frequency range The mean equivalent rectangular bandwidth calculated from the filter shape was approximately 16.0%, 17.0%, 13.6% and 11.3% of the tone frequencies of 40, 60, 80, and 100 kHz.
Determination of crystallographic orientation of large grain metals with surface acoustic waves
Authors: Li Wenqi , Sharples Steve D. , Smith Richard J. , Clark Matt , Somekh Michael G.
Published: August 2012

A previously described laser ultrasonic technique known as spatially resolved acoustic spectroscopy (SRAS) can be used to image surface microstructure, using the local surface acoustic wave (SAW) velocity as a contrast mechanism. It is shown here that measuring the SAW velocity in multiple directions can be used to determine the crystallographic orientation of grains. The orientations are determined by fitting experimentally measured velocities to theoretical velocities. Using this technique the orientations of 12 nickel and 3 aluminum single crystal samples have been measured, and these are compared with x-ray Laue backreflection (LBR) measurements with good agreement. The root mean square difference between SRAS and LBR measurements in terms of an R-value is less than 4.1°. The influence of systematic errors in the SAW velocity determination due to instrument miscalibration, which affects the accurate determination of the planes, is discussed. SRAS has great potential for complementary measurements or even for replacing established orientation determination and imaging techniques.
Enhancing the emergence rate of coherent wavefronts from ocean ambient noise correlations using spatio-temporal filters
Authors: Leroy Charlotte , Lani Shane , Sabra Karim G. , Hodgkiss William S. , Kuperman W. A. , Roux Philippe
Published: August 2012

Extracting coherent wavefronts between passive receivers using cross-correlations of ambient noise (CAN) provides a means for monitoring the seismoacoustic environment without using active sources. However, using cross-correlations between single receivers can require a long recording time in order to extract stable coherent arrivals from CAN. This becomes an issue if the propagation medium fluctuates significantly during the recording period. To address this issue, this article presents a general spatio-temporal filtering procedure to enhance the emergence rate for coherent wavefronts extracted from time-averaged ambient noise correlations between two spatially separated arrays. The robustness of this array-based CAN technique is investigated using ambient shipping noise recorded over 24 h in the frequency band [250–850 Hz] on two vertical line arrays deployed 143 m apart in shallow water (depth 20 m). Experimental results confirm that the array-based CAN technique can significantly reduce the recording duration (e.g., from 22 h to 30 min) required for extracting coherent wavefronts of sufficient amplitude (e.g., 20 dB over residual temporal fluctations) when compared to conventional CAN implementations between single pairs of hydrophones. These improvements of the CAN technique could benefit the development of noise-based ocean monitoring applications such as passive acoustic tomography.
Sound transmission of cavity walls due to structure borne transmission via point and line connections
Authors: Davy John L.
Published: August 2012

The author has published equations for predicting the air borne sound transmission of double leaf cavity walls due to the structure borne sound transmission across the air cavity via (possibly resilient) line connections, but has never published the full derivation of these equations. The author also derived equations for the case when the connections are rigid point connections but has never used them or published them or their derivations. This paper will present the full derivation of the author’s theory of the air borne sound transmission of double leaf cavity walls due to the structure borne sound transmission across the air cavity via point or line connections which are modeled as four pole networks. The theoretical results will be compared with experimental results on wooden stud cavity walls from the National Research Council of Canada because the screw spacing is given for these results. This enables connections via studs and screws to be modeled as point connections and avoids the need to make any assumptions about the compliance of the equivalent point or line connections.
Pitch-interval discrimination and musical expertise: Is the semitone a perceptual boundary?
Authors: Zarate Jean Mary , Ritson Caroline R. , Poeppel David
Published: August 2012

The ability to discriminate pitch changes (or intervals) is foundational for speech and music. In an auditory psychophysical experiment, musicians and non-musicians were tested with fixed- and roving-pitch discrimination tasks to investigate the effects of musical expertise on interval discrimination. The tasks were administered parametrically to assess performance across varying pitch distances between intervals. Both groups showed improvements in fixed-pitch interval discrimination as a function of increasing interval difference. Only musicians showed better roving-pitch interval discrimination as interval differences increased, suggesting that this task was too demanding for non-musicians. Musicians had better interval discrimination than non-musicians across most interval differences in both tasks. Interestingly, musicians exhibited improved interval discrimination starting at interval differences of 100 cents (a semitone in Western music), whereas non-musicians showed enhanced discrimination at interval differences exceeding 125 cents. Although exposure to Western music and speech may help establish a basic interval-discrimination threshold between 100 and 200 cents (intervals that occur often in Western languages and music), musical training presumably enhances auditory processing and reduces this threshold to a semitone. As musical expertise does not decrease this threshold beyond 100 cents, the semitone may represent a musical training-induced intervallic limit to acoustic processing.
A maximum-likelihood procedure for estimating psychometric functions: Thresholds, slopes, and lapses of attention
Authors: Shen Yi , Richards Virginia M.
Published: August 2012

Green [J. Acoust. Soc. Am. 87, 2662–2674 (1990)] suggested an efficient, maximum-likelihood-based approach for adaptively estimating thresholds. Such procedures determine the signal strength on each trial by first identifying the most likely psychometric functions among the pre-proposed alternatives based on responses from previous trials, and then finding the signal strength at the “sweet point” on that most likely function. The sweet point is the point on the psychometric function that is associated with the minimum expected variance. Here, that procedure is extended to reduce poor estimates that result from lapses in attention. The sweet points for the threshold, slope, and lapse parameters of a transformed logistic psychometric function are derived. In addition, alternative stimulus placement algorithms are considered. The result is a relatively fast and robust estimation of a three-parameter psychometric function.
Computation of dynamic seismic responses to viscous fluid of digitized three-dimensional Berea sandstones with a coupled finite-difference method
Authors: Zhang Yang , Toksöz M. Nafi
Published: August 2012

The seismic response of saturated porous rocks is studied numerically using microtomographic images of three-dimensional digitized Berea sandstones. A stress-strain calculation is employed to compute the velocities and attenuations of rock samples whose sizes are much smaller than the seismic wavelength of interest. To compensate for the contributions of small cracks lost in the imaging process to the total velocity and attenuation, a hybrid method is developed to recover the crack distribution, in which the differential effective medium theory, the Kuster-Toksöz model, and a modified squirt-flow model are utilized in a two-step Monte Carlo inversion. In the inversion, the velocities of P- and S-waves measured for the dry and water-saturated cases, and the measured attenuation of P-waves for different fluids are used. By using such a hybrid method, both the velocities of saturated porous rocks and the attenuations are predicted accurately when compared to laboratory data. The hybrid method is a practical way to model numerically the seismic properties of saturated porous rocks until very high resolution digital data are available. Cracks lost in the imaging process are critical for accurately predicting velocities and attenuations of saturated porous rocks.
The hearing threshold of a harbor porpoise (Phocoena phocoena) for impulsive sounds (L)
Authors: Kastelein Ronald A. , Gransier Robin , Hoek Lean , de Jong Christ A. F.
Published: August 2012

The distance at which harbor porpoises can hear underwater detonation sounds is unknown, but depends, among other factors, on the hearing threshold of the species for impulsive sounds. Therefore, the underwater hearing threshold of a young harbor porpoise for an impulsive sound, designed to mimic a detonation pulse, was quantified by using a psychophysical technique. The synthetic exponential pulse with a 5 ms time constant was produced and transmitted by an underwater projector in a pool. The resulting underwater sound, though modified by the response of the projection system and by the pool, exhibited the characteristic features of detonation sounds: A zero to peak sound pressure level of at least 30 dB (re 1 s−1) higher than the sound exposure level, and a short duration (34 ms). The animal’s 50% detection threshold for this impulsive sound occurred at a received unweighted broadband sound exposure level of 60 dB re 1 μPa2s. It is shown that the porpoise’s audiogram for short-duration tonal signals [Kastelein et al., J. Acoust. Soc. Am. 128, 3211–3222 (2010)] can be used to estimate its hearing threshold for impulsive sounds.
Finite element analysis of the dynamic behavior of a laminated windscreen with frequency dependent viscoelastic core
Authors: Bouayed Kaïss , Hamdi Mohamed-Ali
Published: August 2012

This paper presents numerical and experimental validation of results obtained by a shell finite element, which has been developed for modeling of the dynamic behavior of sandwich multilayered structures with a viscoelastic core. The proposed shell finite element is very easy to implement in existing finite element solvers, since it uses only the displacements as degrees of freedom at external faces and at inter-layer interfaces. The displacement field is linearly interpolated in the thickness direction of each layer, and analytical integration is made in the thickness direction in order to avoid meshing of each sandwich layer by solid elements. Only the two dimensional mid-surface of reference is meshed, facilitating the mesh generation task. A simplified modal approach using a real modal basis is also proposed to efficiently calculate the dynamic response of the sandwich structure. The proposed method reduces the memory size and computing time and takes into account the frequency-dependence of the polymer core mechanical properties. Results obtained by the proposed element in conjunction with the simplified modal method have been numerically and experimentally validated by comparison to results obtained by commercial software codes (MSC/nastran and ESI/rayon-vtm), and to measurements done on automobile windscreens.
A superdirective array of phase shift sources
Authors: Simón Gálvez Marcos F. , Elliott Stephen J. , Cheer Jordan
Published: August 2012

A superdirective array of audio drivers is described, which is compact compared with the acoustic wavelength over some of its frequency range. In order to minimize the overall sound power output, and hence reduce the excitation of the reverberant field when used in an enclosed space, the individual drivers are made directional by using phase shift enclosures. The motivating application for the array is the enhancement of sound from a television, in a particular region of space, to aid hearing impaired listeners. The design is initially investigated, using free-field simulations, by comparing the performance of 8 monopoles, 8 phase shift loudspeakers, and a double array of 16 monopoles, with a contrast maximization formulation. The construction and testing of an array of 8 drivers is then discussed, together with its measured response in an anechoic environment. The result of using acoustic contrast maximization is then compared with a least squares formulation, which demonstrates that the performance of the least squares solution can be made similar to that given by acoustic contrast maximization in this application, with a suitable choice of the target field.