bluuebunny/crossref_metadata_2025 huggingface dataset:
Healing outcomes at implants installed in grafted sites: an experimental study in dogs
Authors: De Santis Enzo , Lang Niklaus P. , Scala Alessandro , Viganò Paolo , Salata Luiz A. , Botticelli Daniele
Published: October 2011

Aim

To evaluate the integration of implants installed using a surgical guide in augmented sites with autologous bone or deproteinized bovine bone mineral (DBBM) blocks, concomitantly with a collagen membrane.

Material and methods

Mandibular molars were extracted bilaterally in six Labrador dogs, the buccal bony wall was removed, and a box‐shaped defect was created. After 3 months, flaps were elevated, a bony graft was harvested from the ascending ramus, and secured to the lateral wall of the defect by means of screws. In the left mandibular side, a DBBM block was fixed into the defect. A resorbable membrane was applied at both sides, and the flaps were sutured. After 3 months, flaps were elevated, and a customized device was used as surgical guide to prepare the recipient sites in the interface between grafts and parent bone. One implant was installed in each side of the mandible. After 3 months, biopsies were harvested, and ground sections were prepared for histologic evaluation.

Results

One autologous bone block graft was lost before implant installation. The width of the alveolar crest at the test sites (DBBM) was 5.4 ± 1.2 mm before, 9.4 ± 1.2 mm immediately after grafting, and 9.3 ± 1 mm at implant installation. At the control sites (autologous bone), the corresponding values were: 5.2 ± 1, 9 ± 1.2, and 8.7 ± 0.9 mm, respectively. All implants installed were available for histologic evaluation (n = 5). The autologous bone grafts, rich in vessels and cells, were integrated in the parent bone, and only little non‐vital bone was found. The BIC% was 56.7 ± 15.6% and 54.2 ± 13.2% at the buccal and lingual aspects, respectively. At the test sites, the DBBM appeared to be embedded into connective tissue, and very little newly formed bone was encountered within the grafts. The BIC% was 5.8 ± 12.3% and 51.3 ± 14.2% at the buccal and lingual aspects, respectively.

Conclusions

Autologous bone blocks used to augment the alveolar bony crest horizontally allowed the complete osseointegration of implants installed after 3 months of healing. However, similar blocks of DBBM did not promote osseointegration, although the installed implants were stable owing to the osseointegration in the sites of the parent bone.
MODELING OF PREHEAT TREATMENT OPTIMIZATION APPLIED TO FRESH‐CUT “ROCHA” PEAR
Authors: ABREU MARTA , ALEGRIA CARLA , GONÇALVES ELSA M. , PINHEIRO JOAQUINA , MOLDÃO‐MARTINS MARGARIDA , EMPIS JOSÉ
Published: October 2011

Response surface methodology based on a five‐level, three‐variable central composite rotatable design was used for modeling the effects of preheat treatments on fresh‐cut “Rocha” pear quality. Studied variables were time (t: 0–150 min), temperature (T: 20–50C) and posttreatment storage time (St: 0–20 days, 5C). The quality‐affecting parameters including color, firmness, pH, soluble solid content, and total ascorbic acid content were the monitored dependent variables. Results provide reasonable estimation of the impact of preheat treatments on the quality of fresh‐cut “Rocha” pear and its shelf life. The time–temperature range of 33–41C during less than 20 min was selected as the conditions that best provided surface browning control, without impairing other studied quality parameters, with an estimated 8‐day shelf life period. The achieved kinetic changes of polyphenoloxidase, partial reduction in enzyme activity (ca. 23%) and depletion of phenolic content (ca. 11%) could be responsible for the browning control.

PRACTICAL APPLICATIONS

Minimal processing, namely cutting operations, triggers physiological reactions which limit fresh‐cut Rocha pear shelf life. Superficial browning is one of the major concerns to this industry, and new “clean” methodologies aiming at the inhibition of such reaction and maximization of the product shelf life will benefit not only from product marketability but also will respond to the consumers' demand of “chemical free” products. Heat treatments have been used to improve fresh‐cut commodities' browning resistance. The present work evaluated the use of preheat treatments against this physiological disorder during storage. Results will provide an optimized preheat treatment that grants high‐quality fresh‐cut Rocha pear with suitable shelf life.
Contrast‐enhanced ultrasonography in the differentiation of retinal detachment and vitreous membrane in dogs and cats
Authors: Labruyere J. J. , Hartley C. , Holloway A.
Published: October 2011

Objectives: To evaluate contrast‐enhanced ultrasonography (CEU) and colour Doppler imaging (CDI) for detection of persistent vascularisation in retinal detachment.

Methods: In 22 eyes, retinal detachment (n=13) and vitreous membranes (n=9) were confirmed by ophthalmological examination, during cataract surgery, by histopathology or after vitreoretinal surgery. Tentative diagnosis of retinal detachment or vitreous membrane was made using grey‐scale B‐mode ultrasonography. Assessment of retinal detachment was based on the presence or absence of vascularisation in the membranous structure using CDI and CEU.

Results: Sensitivity, specificity, positive‐predictive value and negative‐predictive value of grey‐scale ultrasonography in differentiating retinal detachment from vitreous membrane were 92·3%, 66·6%, 80% and 85·7%. In 91% of eyes, colour Doppler assessment was unsuccessful due to the movement of the eye. Persistent vascularisation was demonstrated in all cases of retinal detachments with CEU. CEU was 100% accurate for detection and differentiation between retinal detachment and vitreous membrane.

Clinical Significance: CEU is a useful clinical tool for the diagnosis of retinal detachment and vitreous membrane in dogs and cats.
Canine hip dyslasia: the significance of the Norberg angle for healthy breeding
Authors: Comhaire F. H. , Schoonjans F. A.
Published: October 2011

Objectives: To assess the reproducibility of the Fédération Cynologique Internationale (FCI) classification over time, and between assessors and to evaluate the benefit of computer‐assisted measurement of the Norberg angle and of its percentile ranking by breed for the diagnosis of canine hip dysplasia, and for the selection of couples for breeding.

Methods: During the time period of 2006 to 2010, 5094 hip radiographs were evaluated according to the FCI rules, and 4400 have been submitted for statistical analysis. A system of computer‐assisted image analysis (Digimizer®, MedCalc Software Ltd, Mariakerke, Belgium) was used to measure the Norberg angle. The Norberg angle value of individual dogs was expressed as percentile rank by breed.

Results: The agreement between individual assessors was highly significant (P<0·001), but there were important variations over time of the ratio of classes A or B. The Norberg angle and the percentile rank accurately discriminated between dogs with or without canine hip dysplasia, with positive and negative likelihood ratios of 6·31 and 0·21, respectively, for the Norberg angle at criterion value of 102·2°, and 4·21 and 0·18 for the percentile rank at criterion value of the 25th percentile.

ClinicalSignificance: The percentile rank of the Norberg angle may be a valuable tool for breeding selection.
Traumatic urothorax in a dog: a case report
Authors: Klainbart S. , Merchav R. , Ohad D. G.
Published: October 2011

Pleural effusion caused by post‐traumatic extravasation of urine from the abdominal cavity to the pleural cavity (urothorax) is an uncommon complication following traumatic injury. To the authors' knowledge, this is the first report of a case of traumatic urothorax in a dog presented with pleural and abdominal urine effusion. Combined urothorax and uroabdomen should be included in the differentialdiagnosis list for dogs with recent trauma and a bicavitary effusion. The diagnosis can be confirmed by elevated creatinine concentrations in both effusates, compared to its serum concentration.
Is There a Right Way to Nudge? The Practice and Ethics of Choice Architecture
Authors: Selinger Evan , Whyte Kyle
Published: October 2011

Cass Sunstein and Richard Thaler’s Nudge: Improving Decisions about Health, Wealth, and Happiness presents an influential account of why ‘choice architecture’ should be used to ‘nudge’ people into making better decisions than they would otherwise make. In this essay we: (1) explain the main concepts that Thaler and Sunstein rely upon to defend their project; (2) clarify the main conceptual problems that have arisen in discussions about nudges; (3) clarify practical difficulties that can arise during nudge practice; (4) review the main ethical and political objections that have been raised against nudging; and (5) clarify why issues related to meaning can pose methodological problems for creating effective choice architecture.
Risk Assessment Tools and Racial/Ethnic Disparities in the Juvenile Justice System
Authors: Moore Lori D. , Padavic Irene
Published: October 2011

This paper addresses the possible consequences for racial and ethnic disparities of the growing reliance on risk assessment tools for sentencing in juvenile justice systems. These tools consider both legal factors (i.e. criminal history) and personal background factors (e.g. household composition, parents’ arrest history, the youth’s mental health, attitudes, school status, and current employment status) to predict the likelihood of recidivism, which then informs punishment decisions. Because they decontextualize race, the associations between race and risk factors linked to race could possibly create higher risk scores and harsher punishments for minority youth.
Nujiangia(Orchidaceae: Orchideae): A new genus from the Himalayas
Authors: JIN Xiao‐Hua , LI De‐Zhu , XIANG Xiao‐Guo , LAI Yang‐Jun , SHI Xiao‐Chun
Published: October 2011

Abstract The phylogenetic positions of the enigmatic “wildcard” taxon,Habenaria griffithii, were inferred from molecular data and morphological evidence. Morphologically,H. griffithiiis quite “isolated” inHabenaria; instead, it is close toGennaria, Diphylax, Peristylus, andPlatanthera. It can be distinguished from these four genera by its slender staminodes conspicuously longer than the anther, rostellum having two relatively long arms, lip and lateral sepals connate in the basal part, and a transverse cushion‐shaped stigma. An analysis of combined plastid and nuclear data (rbcL,matK, and internal transcribed spacer) using Bayesian and parsimony methods revealed thatH. griffithiiis closest toGennaria, a monotypic genus restricted to the western Mediterranean and Canary Islands. On this basis, a new genus,Nujiangia,is tentatively proposed to accommodate this taxon. In addition to the taxonomic treatment of this genus, the delimitation of many related genera in Orchideae is discussed.
Higher concentration local anaesthetics causing prolonged anaesthesia. Do they? A literature review and case reports
Authors: Kingon A , Sambrook P , Goss A
Published: October 2011

Higher concentration dental local anaesthetics (3% and 4%) have become more available in Australia in recent years. Benefits claimed include a faster onset of anaesthesia and improved success with injections compared to 2% solutions. Recent reports suggest that the higher concentration carries a greater risk of prolonged anaesthesia to the mandibular and particularly the lingual nerves. The literature was reviewed and those studies which demonstrated adverse effects of different concentrations of local anaesthetics were analysed. Recent cases are presented. There is an extensive international literature which confirms increased concentration of local anaesthetic does show an increased risk, by about ×6, of prolonged anaesthesia. Five case reports illustrate the impact of this complication on patients’ quality of life. Careful consideration needs to be given before using higher concentration local anaesthetic agents for mandibular and lingual blocks as lower concentration local anaesthetics are safer. If acceptable to individual patients, avoidance of block injections or any local anaesthetic for minor restorative tasks could be encouraged given the severity of the complication. It is safe to use the higher concentration agents for infiltrations away from major nerves.
Site‐occupancy modelling as a novel framework for assessing test sensitivity and estimating wildlife disease prevalence from imperfect diagnostic tests
Authors: Lachish Shelly , Gopalaswamy Arjun M. , Knowles Sarah C. L. , Sheldon Ben C.
Published: October 2011

1. Reliable assessments of infection status and population prevalence are critical for epidemiological modelling and disease management, but can be greatly biased when disease state is determined from imperfect diagnostic tests. Available statistical methods to adjust test‐based prevalence estimates by correcting for test accuracy demand that many stringent requirements and assumptions be met (knowledge about underlying population prevalence or multiple diagnostic methods), limiting their utility for wildlife disease surveys.

2. In this paper, we present site‐occupancy modelling as a flexible approach to derive estimates of population prevalence and test sensitivity under imperfect pathogen detection without a need for restrictive requirements or assumptions. We extend the utility of the standard site‐occupancy framework for pathogen detection data by novel application of abundance‐induced heterogeneity (AIH) models (Royle & Nichols 2003) that allow test sensitivity to vary with host pathogen load or infection intensity.

3. We demonstrate the utility of this approach for wildlife disease studies by applying site‐occupancy models to a data set consisting of replicate quantitative (q)PCR diagnoses of malaria parasites (Plasmodium spp.) in blood samples from wild blue tits (Cyanistes caeruleus).

4. Model selection revealed that Plasmodium detection rates by qPCR were strongly dependent on host parasite load. Estimates of parasite detection rates revealed the qPCR assay to be highly sensitive, with accordingly, a very low probability of false negative diagnosis for the majority of infected hosts in our population and little bias in naive estimates of population prevalence, although this will be a system‐specific result.

5. Our results demonstrate the utility of a site‐occupancy approach for deriving estimates of population prevalence under imperfect pathogen detection and reveal that accounting for host variation in pathogen load allows a more accurate assessment of diagnostic test sensitivity.

6. By identifying factors that influence pathogen detection rates, and revealing optimal protocols for obtaining unbiased prevalence estimates, while minimising the probability of false negative diagnoses, we also show that this approach can enhance both diagnostic accuracy and cost‐efficiency in wildlife disease surveys.
Global and Local Elastic-Plastic Stress Analysis of Coke Drum Under Thermal-Mechanical Loadings
Authors: Ju Feng , Aumuller John , Xia Zihui , Du Plessis Pierre
Published: October 2011

Coke drums are critical equipment in the petroleum industry. The failure modes of coke drums include excessive bulging deformation and fatigue cracking. The elastic-plastic behavior of a coke drum, subjected to both thermal and mechanical loadings, is analyzed for a complete cycle of operation. The effects of multiple operational cycles and localized hot/cold spots are also investigated. It is found that yielding of the clad layer starts at the very early stage in an operating cycle and permanent deformation is caused in the first operating cycle. Plastic shakedown occurs in the clad layer under combined operating thermal and mechanical loadings. It is also found that both hot and cold spots will cause bulging of the shell and the cold spot can cause more severe deformation than the hot spot.
Hole Crack Problems in Infinite Plate Subjected to Uniform Internal Pressure
Authors: Yan Xiangqiao , Liu Baoliang
Published: October 2011

This brief deals with crack(s) emanating from a hole in infinite plate subjected to uniform internal pressure. Such a crack problem is called a hole crack problem for short. By using a hybrid displacement discontinuity method (a boundary element method) proposed recently by Yan, three hole crack problems (an elliptical hole crack problem, a rhombus hole crack problem, and a triangle hole crack problem) in infinite plate subjected to uniform internal pressure are analyzed in detail. By changing hole geometry form and hole geometry parameters and by comparing the stress intensity factors (SIFs) of the hole crack problem with those of the center crack problem, the effect of the hole geometry form and hole geometry parameters on the SIFs is revealed. It is found that a hole has a shielding and an amplifying effect on the SIFs of crack(s) emanating from the hole. The shielding and amplifying effects are varied with hole geometry form and hole geometry parameters.
Effect of Double Stratification on Free Convection in a Micropolar Fluid
Authors: Srinivasacharya D. , RamReddy Ch.
Published: October 2011

This paper analyzes the flow and heat and mass transfer characteristics of the free convection on a vertical plate with uniform and constant heat and mass fluxes in a doubly stratified micropolar fluid. The nonlinear governing equations and their associated boundary conditions are initially cast into dimensionless forms by pseudosimilarity variables. The resulting system of equations is then solved numerically using the Keller-box method. The numerical results are compared and found to be in good agreement with previously published results on special cases of the problem. The obtained results are displayed graphically to illustrate the effect of the micropolar and stratification parameters on the dimensionless velocity, microrotation, wall temperature, and wall concentration. The numerical values of the skin friction, wall couple stress, and heat and mass transfer rates for different values of governing parameters are also tabulated.
Leveling Intermittent Renewable Energy Production Through Biomass Gasification-Based Hybrid Systems
Authors: Dean Jered , Braun Robert , Penev Michael , Kinchin Christopher , Muñoz David
Published: October 2011

The increased use of intermittent renewable power in the United States is forcing utilities to manage increasingly complex supply and demand interactions. This paper evaluates biomass pathways for hydrogen production and how they can be integrated with renewable resources to improve the efficiency, reliability, dispatchability, and cost of other renewable technologies. Two hybrid concepts were analyzed that involve coproduction of gaseous hydrogen and electric power from thermochemical biorefineries. Both of the concepts analyzed share the basic idea of combining intermittent wind-generated electricity with a biomass gasification plant. The systems were studied in detail for process feasibility and economic performance. The best performing system was estimated to produce hydrogen at a cost of $1.67/kg. The proposed hybrid systems seek to either fill energy shortfalls by supplying hydrogen to a peaking natural gas turbine or to absorb excess renewable power during low-demand hours. Direct leveling of intermittent renewable electricity production was proposed utilizing either an indirectly heated biomass gasifier or a directly heated biomass gasifier. The indirect gasification concepts studied were found to be cost competitive in cases where value is placed on controlling carbon emissions. A carbon tax in the range of $26–40 per metric ton of CO2 equivalent (CO2e) emission makes the systems studied cost competitive with steam methane reforming (SMR) to produce hydrogen. The direct gasification concept studied replaces the air separation unit (ASU) with an electrolyzer bank and is unlikely to be cost competitive due to high capital costs. Based on a direct replacement of the ASU with electrolyzers, hydrogen can be produced for $0.27 premium per kilogram. Additionally, if a nonrenewable, grid-mix electricity is used, the hybrid system is found to be a net CO2e emitter.
Experiments on stress dependent borehole acoustic waves
Authors: Hsu Chaur-Jian , Kane Michael R. , Winkler Kenneth , Wang Canyun , Linton Johnson David
Published: October 2011

In the laboratory setup, a borehole traverses a dry sandstone formation, which is subjected to a controlled uniaxial stress in the direction perpendicular to the borehole axis. Measurements are made in a single loading-unloading stress cycle from zero to 10 MPa and then back down to zero stress. The applied stress and the presence of the borehole induce anisotropy in the bulk of the material and stress concentration around the borehole, both azimuthally and radially. Acoustic waves are generated and detected in the water-filled borehole, including compressional and shear headwaves, as well as modes of monopole, dipole, quadrupole, and higher order azimuthal symmetries. The linear and non-linear elastic parameters of the formation material are independently quantified, and utilized in conjunction with elastic theories to predict the characteristics of various borehole waves at zero and finite stress conditions. For example, an analytic theory is developed which is successfully used to estimate the changes of monopole tube mode at low frequency resulted from uniaxial stress, utilizing the measured material third order elasticity parameters. Comparisons between various measurements as well as that between experiments and theories are also presented.
Evidence of across-channel processing for spectral-ripple discrimination in cochlear implant listeners
Authors: Ho Won Jong , Jones Gary L. , Drennan Ward R. , Jameyson Elyse M. , Rubinstein Jay T.
Published: October 2011

Spectral-ripple discrimination has been used widely for psychoacoustical studies in normal-hearing, hearing-impaired, and cochlear implant listeners. The present study investigated the perceptual mechanism for spectral-ripple discrimination in cochlear implant listeners. The main goal of this study was to determine whether cochlear implant listeners use a local intensity cue or global spectral shape for spectral-ripple discrimination. The effect of electrode separation on spectral-ripple discrimination was also evaluated. Results showed that it is highly unlikely that cochlear implant listeners depend on a local intensity cue for spectral-ripple discrimination. A phenomenological model of spectral-ripple discrimination, as an “ideal observer,” showed that a perceptual mechanism based on discrimination of a single intensity difference cannot account for performance of cochlear implant listeners. Spectral modulation depth and electrode separation were found to significantly affect spectral-ripple discrimination. The evidence supports the hypothesis that spectral-ripple discrimination involves integrating information from multiple channels.
Source parameters of echolocation clicks from wild bottlenose dolphins (Tursiops aduncusandTursiops truncatus)
Authors: Wahlberg Magnus , Jensen Frants H. , Aguilar Soto Natacha , Beedholm Kristian , Bejder Lars , Oliveira Cláudia , Rasmussen Marianne , Simon Malene , Villadsgaard Anne , Madsen Peter T.
Published: October 2011

The Indian Ocean and Atlantic bottlenose dolphins (Tursiops aduncus and Tursiops truncatus) are among the best studied echolocating toothed whales. However, almost all echolocation studies on bottlenose dolphins have been made with captive animals, and the echolocation signals of free-ranging animals have not been quantified. Here, biosonar source parameters from wild T. aduncus and T. truncatus were measured with linear three- and four-hydrophone arrays in four geographic locations. The two species had similar source parameters, with source levels of 177–228 dB re 1 μPa peak to peak, click durations of 8–72 μs, centroid frequencies of 33–109 kHz and rms bandwidths between 23 and 54 kHz. T. aduncus clicks had a higher frequency emphasis than T. truncatus. The transmission directionality index was up to 3 dB higher for T. aduncus (29 dB) as compared to T. truncatus (26 dB). The high directionality of T. aduncus does not appear to be only a physical consequence of a higher frequency emphasis in clicks, but may also be caused by differences in the internal properties of the sound production system.
The feasibility of pulse compression by nonlinear effective bandwidth extension
Authors: Clement Gregory T. , Nomura Hideyuki , Kamakura Tomoo
Published: October 2011

Chirp-encoded excitation has been utilized for increased signal-to-noise ratio (SNR) in both linear and harmonic imaging. In either case, it is necessary to isolate the relevant frequency band to avoid artifacts. In contrast, the present study isolates and then combines the fundamental and the higher harmonics, treating them as a single, extended bandwidth. Pulse-inverted sum and difference signals are first used to isolate even and odd harmonics. Matched filters specific to the source geometry and the transmit signal are then separately applied to each harmonic band. Verification experiments are performed using up to the third harmonic resulting from an underwater chirp excitation. Analysis of signal peaks after scattering from a series of steel and nylon wires indicates increased compression using the extended bandwidth, as compared to well-established methods for fundamental and second harmonic chirp compression. Using third harmonic bands, a mean pulse width of 56% relative to fundamental compression and 48% relative to second harmonic compression was observed. Further optimization of the compression by altering the transmission indicated 17% additional reduction in the pulse width and a 47% increase in peak-to-sidelobe ratio. Overall, results establish the feasibility of extended bandwidth signal compression for simultaneously increasing SNR and signal resolution.
Temperature dependent ultrasonic characterization of biological media
Authors: Ghoshal Goutam , Luchies Adam C. , Blue James P. , Oelze Michael L.
Published: October 2011

Quantitative ultrasound (QUS) is an imaging technique that can be used to quantify tissue microstructure giving rise to scattered ultrasound. Other ultrasonic properties, e.g., sound speed and attenuation, of tissues have been estimated versus temperature elevation and found to have a dependence with temperature. Therefore, it is hypothesized that QUS parameters may be sensitive to changes in tissue microstructure due to temperature elevation. Ultrasonic backscatter experiments were performed on tissue-mimicking phantoms and freshly excised rabbit and beef liver samples. The phantoms were made of agar and contained either mouse mammary carcinoma cells (4T1) or chinese hamster ovary cells (CHO) as scatterers. All scatterers were uniformly distributed spatially at random throughout the phantoms. All the samples were scanned using a 20-MHz single-element f/3 transducer. Quantitative ultrasound parameters were estimated from the samples versus increases in temperature from 37 °C to 50 °C in 1 °C increments. Two QUS parameters were estimated from the backscatter coefficient [effective scatterer diameter (ESD) and effective acoustic concentration (EAC)] using a spherical Gaussian scattering model. Significant increases in ESD and decreases in EAC of 20%–40% were observed in the samples over the range of temperatures examined. The results of this study indicate that QUS parameters are sensitive to changes in temperature.
Tonal vocalizations in the red wolf (Canis rufus): Potential functions of nonlinear sound production
Authors: Schneider Jennifer N. , Anderson Rita E.
Published: October 2011

The purpose of this study is to further understanding of the function of nonlinear vocalizations in red wolves (Canis rufus) by examining the acoustic, structural, and contextual characteristics of nonlinear sounds as compared to linear sounds. Video recordings of captive wolves from a breeding facility were analyzed. The acoustic nature of sound units was consistent with that of other social canids. The sound units included high-frequency squeaks (2600–9500 Hz) and low-frequency wuhs (160–1600 Hz) occurring either as separate units or in combination as nonlinear units (squeak-wuh frequency jumps, biphonations, squeaks with sidebands) and frequency jumps within squeaks. These low-amplitude sounds occurred in trains of 1–30 units that were classified as squeak vocalizations (49%), wuh vocalizations (19%), and nonlinear vocalizations (any combination including one or more nonlinear units, 32%). Nonlinear vocalizations transitioned directionally from high-frequency units to mixed-frequency units which has implications for the study of sound production and function. Wolves squeaked most often when oriented toward others, implying a solicitation function, while wuh vocalizations were more common during social interactions. Nonlinear vocalizations occurred most often during penmate-play or when oriented toward neighbors, indicating that nonlinear sound production may signal an increase in arousal.
A cautionary note on the use of the adaptive up–down method
Authors: García-Pérez Miguel A.
Published: October 2011

Up–down staircases with equal sizes for the steps up and down are widely used to estimate detection and discrimination thresholds in psychoacoustics, but the conventional average-of-reversals estimator does not converge on its presumed percent point in Yes–No tasks or in two-alternative forced-choice detection tasks. The particular percent point of convergence is partly determined by the relative size of the steps with respect to the spread (inverse of slope) of the underlying psychometric function. In particular, threshold is increasingly underestimated as the spread of the psychometric function decreases. This characteristic may have serious consequences when thresholds estimated via up–down staircases are compared across conditions in which the spread of the psychometric function varies, because then these thresholds do not represent comparable measures of performance. This paper documents the misbehavior of the average-of-reversals estimator under up–down rules and types of forced-choice task that are in common use in psychoacoustics but which have not been studied before in simulations. It is also shown that a relatively simple modification of the up–down design (namely, using steps up and down of different size and in a certain ratio depending only on the task and the up–down rule being used) stabilizes the performance of these staircases.
Data completion method for the characterization of sound sources
Authors: Langrenne Christophe , Garcia Alexandre
Published: October 2011

This paper presents a different approach to solve the inverse acoustic problem. This problem is an “ill-posed” problem since the solution is very sensitive to measurement precision. A classical way to solve this problem consists in inversing a propagation operator which relates structure quantities (acoustic pressures or gradients) to near-field quantities (acoustic pressures or gradients). This can be achieved by using near-field acoustical holography (NAH) in separable coordinate systems. In order to overcome this limitation, the inverse boundary element method (IBEM) can be implemented to recover all acoustic quantities in a three-dimensional space and on an arbitrary three-dimensional source surface. In this paper, the data completion method (DCM) is developed: the acoustic gradients and pressures are known on a surface surrounding the source, but are unknown on its structure. The solution is given by the resolution of the Helmholtz formulation applied on the empty domain between the two boundaries made by the measurements quantities and the structure of the source. The conventional method applies directly the integral formulation for the empty domain. Another way of solving this Helmholtz formulation can be achieved by splitting it in two well-posed subproblems in a Steklov-Poincaré’s formulation. The data completion method allows one to solve the problem with acoustic perturbations due to sources on the exterior domain, or due to a confined domain, without altering the results.
Development of a contact call in black-capped chickadees (Poecile atricapillus) hand-reared in different acoustic environments
Authors: Guillette Lauren M. , Bloomfield Laurie L. , Batty Emily R. , Dawson Michael R. W. , Sturdy Christopher B.
Published: October 2011

The tseet contact call, common to black-capped (Poecile atricapillus) and mountain chickadees (P. gambeli), is the most frequently produced vocalization of each species. Previous work has characterized the tseet call of black-capped and mountain chickadees from different geographic locations in terms of nine acoustic features. In the current study, using similar methods, the tseet call of black-capped chickadees that were hand reared with either conspecifics, heterospecifics (mountain chickadees), or in isolation from adult chickadees are described. Analysis of call features examined which acoustic features were most affected by rearing environment, and revealed that starting frequency and the slope of the descending portion of the tseet call differed between black-capped chickadees reared with either conspecific or heterospecific adults. Birds reared in isolation from adults differed from the other hand-reared groups on almost every acoustic feature. Chickadee tseet calls are more individualized when they are reared with adult conspecifics or heterospecifics compared to chickadees that are reared in isolation from adults. The current results suggest a role of learning in this commonly used contact call.
Experimental study of the influence of low frequency flow modulation on the whistling behavior of a corrugated pipe
Authors: Kristiansen Ulf R. , Mattei Pierre-Olivier , Pinhede Cedric , Amielh Muriel
Published: October 2011

It is well known that airflow in a corrugated pipe can excite whistling at the frequencies of the pipe’s longitudinal acoustic modes. This short contribution reports on the results of experiments where a low frequency, oscillating flow with velocity magnitudes of the same order as the airflow has been added. Depending on the oscillation strength, it has been found that this flow may silence the pipe or move the whistling to higher harmonics. It is also shown that the low frequency oscillation itself may excite higher frequency whistling sounds in the pipe.
Ambient noise in large rivers (L)
Authors: Vračar Miodrag S. , Mijić Miomir
Published: October 2011

This paper presents the results of hydroacoustic noise research in three large European rivers: the Danube, the Sava, and the Tisa. Noise in these rivers was observed during a period of ten years, which includes all annual variation in hydrological and meteorological conditions (flow rate, speed of flow, wind speed, etc.). Noise spectra are characterized by wide maximums at frequencies between 20 and 30 Hz, and relatively constant slope toward higher frequencies. Spectral level of noise changes in time in relatively wide limits. At low frequencies, below 100 Hz, the dynamics of noise level is correlated with the dynamics of water flow and speed. At higher frequencies, noise spectra are mostly influenced by human activities on river and on riverbanks. The influence of wind on noise in rivers is complex due to the annual variation of river surface. The influence of wind is less pronounced than in oceans, seas, and lakes.
Scattering of a spherical wave by a small sphere: An elementary solution
Authors: Godin Oleg A.
Published: October 2011

Wave scattering by objects that are small compared to the wavelength (Rayleigh scattering) is usually studied for plane incident waves. However, knowledge of the full Green’s function of the problem becomes necessary when the separation of scatterers from either an interface or each other is comparable to the scatterers’ dimensions. Here, an elementary analytic solution is derived for diffraction of a spherical sound wave by a small, soft sphere. The approximate solution is obtained from asymptotic expansions of an exact solution, holds everywhere outside the sphere, and reduces to classical results due to Kelvin and Rayleigh in appropriate special cases.
A causal and fractional all-frequency wave equation for lossy media
Authors: Holm Sverre , Näsholm Sven Peter
Published: October 2011

This work presents a lossy partial differential acoustic wave equation including fractional derivative terms. It is derived from first principles of physics (mass and momentum conservation) and an equation of state given by the fractional Zener stress-strain constitutive relation. For a derivative order α in the fractional Zener relation, the resulting absorption αk obeys frequency power-laws as αk ∝ ω1+α in a low-frequency regime, αk ∝ ω1–α/2 in an intermediate-frequency regime, and αk ∝ ω1–α in a high-frequency regime. The value α = 1 corresponds to the case of a single relaxation process. The wave equation is causal for all frequencies. In addition the sound speed does not diverge as the frequency approaches infinity. This is an improvement over a previously published wave equation building on the fractional Kelvin–Voigt constitutive relation.
Intelligibility of reverberant noisy speech with ideal binary masking
Authors: Roman Nicoleta , Woodruff John
Published: October 2011

For a mixture of target speech and noise in anechoic conditions, the ideal binary mask is defined as follows: It selects the time-frequency units where target energy exceeds noise energy by a certain local threshold and cancels the other units. In this study, the definition of the ideal binary mask is extended to reverberant conditions. Given the division between early and late reflections in terms of speech intelligibility, three ideal binary masks can be defined: an ideal binary mask that uses the direct path of the target as the desired signal, an ideal binary mask that uses the direct path and early reflections of the target as the desired signal, and an ideal binary mask that uses the reverberant target as the desired signal. The effects of these ideal binary mask definitions on speech intelligibility are compared across two types of interference: speech shaped noise and concurrent female speech. As suggested by psychoacoustical studies, the ideal binary mask based on the direct path and early reflections of target speech outperforms the other masks as reverberation time increases and produces substantial reductions in terms of speech reception threshold for normal hearing listeners.
Beamforming using compressive sensing
Authors: Edelmann Geoffrey F. , Gaumond Charles F.
Published: October 2011

Compressive sensing (CS) is compared with conventional beamforming using horizontal beamforming of at-sea, towed-array data. They are compared qualitatively using bearing time records and quantitatively using signal-to-interference ratio. Qualitatively, CS exhibits lower levels of background interference than conventional beamforming. Furthermore, bearing time records show increasing, but tolerable, levels of background interference when the number of elements is decreased. For the full array, CS generates signal-to-interference ratio of 12 dB, but conventional beamforming only 8 dB. The superiority of CS over conventional beamforming is much more pronounced with undersampling.
Calibration of otoacoustic emission probe microphones
Authors: Rasetshwane Daniel M. , Neely Stephen T.
Published: October 2011

Recently, investigators of otoacoustic emissions (OAEs) have shown interest in measuring OAEs to frequencies higher than 10 kHz. Most commercial instruments used to measure OAEs do not specify the microphone frequency response at higher frequencies, nor does their typically integrated design make it convenient to measure it. OAE probes manufactured by Etymotic Research have reasonably constant microphone sensitivity up to about 10 kHz and allow direct access to both the sound sources and microphone preamplifier output. A detailed procedure for calibrating the Etymotic Research OAE probe microphone to extend its usable frequency range to frequencies up to 20 kHz is described.
Automatic speech recognition using articulatory features from subject-independent acoustic-to-articulatory inversion
Authors: Ghosh Prasanta Kumar , Narayanan Shrikanth
Published: October 2011

An automatic speech recognition approach is presented which uses articulatory features estimated by a subject-independent acoustic-to-articulatory inversion. The inversion allows estimation of articulatory features from any talker’s speech acoustics using only an exemplary subject’s articulatory-to-acoustic map. Results are reported on a broad class phonetic classification experiment on speech from English talkers using data from three distinct English talkers as exemplars for inversion. Results indicate that the inclusion of the articulatory information improves classification accuracy but the improvement is more significant when the speaking style of the exemplar and the talker are matched compared to when they are mismatched.
LOCATION DYNAMICS OF FOREIGN BANKING IN SHANGHAI FROM 1990 TO 2009
Authors: FENG XIAOBING , KIM BEOM JUN
Published: October 2011

This study examined the determinants of foreign bank location decisions in Shanghai markets over the period of 1990 to 2009. The growing foreign presence in Shanghai was found to be related to two different policy regimes: Pudong development area foreign enterprise clustering period after China opened Pudong, and "deposit-loan-match principle" implementing period after China joined WTO. The current location pattern was found to be correlated to deposit potential in each district. It is evident that the foreign bank location decisions were influenced by those of domestic banks while the reverse did not hold. These findings provide a valuable platform for theoretical modeling and further analysis.
STOCK MARKET DIFFERENCES IN CORRELATION-BASED WEIGHTED NETWORK
Authors: YOUN JANGHYUK , LEE JUNGHOON , CHANG WOOJIN
Published: October 2011

We examined the sector dynamics of Korean stock market in relation to the market volatility. The daily price data of 360 stocks for 5019 trading days (from January, 1990 to August, 2008) in Korean stock market are used. We performed the weighted network analysis and employed four measures: the average, the variance, the intensity, and the coherence of network weights (absolute values of stock return correlations) to investigate the network structure of Korean stock market. We performed regression analysis using the four measures in the seven major industry sectors and the market (seven sectors combined). We found that the average, the intensity, and the coherence of sector (subnetwork) weights increase as market becomes volatile. Except for the "Financials" sector, the variance of sector weights also grows as market volatility increases. Based on the four measures, we can categorize "Financials," "Information Technology" and "Industrials" sectors into one group, and "Materials" and "Consumer Discretionary" sectors into another group. We investigated the distributions of intrasector and intersector weights for each sector and found the differences in "Financials" sector are most distinct.
LEVERAGING SOFTWARE REUSE WITH KNOWLEDGE MANAGEMENT IN SOFTWARE DEVELOPMENT
Authors: PANAGIOTOU DIMITRIS , MENTZAS GREGORIS
Published: October 2011

Managing knowledge in software development is very important, since software development is a human and knowledge intensive activity. The main asset of a software organization consists of its intellectual capital. In this paper we propose KnowBench, a novel knowledge management system that integrates into the daily software development process and can be used for capturing knowledge and experience as soon as it is generated by providing lightweight tools based on Semantic Web technologies. This approach supports developers during the software development process to produce better quality software. The goal of KnowBench is to support the whole knowledge management process when developers design and implement software by supporting identification, acquisition, development, distribution, preservation, and use of knowledge — the building blocks of a knowledge management system.
A COMPARATIVE STUDY OF META/PARA SUBSTITUTION EFFECTS ON THE HYDROGEN-BONDED COMPLEX OF ANILINE-H2O: OBSERVATIONS FROM COMPUTATION
Authors: TAN YING , ZHU LIJUAN , XIAO XIUCHAN , HE SHUHUA , GUO YANZHI , WEN ZHINING , LI MENGLONG , PU XUEMEI , TIAN ANMIN
Published: October 2011

Compared with para-substitution, substituent effects ( R = NH 2, OH , CH 3, F , Cl , H , SiH 3, CHO , CN , NO 2) of meta-position effects on hydrogen-bonded complex of aniline with one water molecule are studied at B3LYP/6-311++G(d,p) level of theory. The differences in hydrogen bonding and some properties associated with the H -bond (such as bond length, vibrational frequency, binding energies, p K a values of aniline derivatives) are discussed between meta and para substitutions. Natural bond orbital (NBO) and atoms in molecules (AIM) analysis are applied to investigate the physical origin of the differences. The results show that the differences are mainly attributed to the variations in electron delocalization from amino group to phenyl ring (reflected by [Formula: see text] interaction) induced by substituents.
DISSIPATIVE PARTICLE DYNAMICS SIMULATION STUDY ON CONTROLLING MOLECULAR WEIGHT DISTRIBUTION IN EMULSION POLYMERIZATION
Authors: ZHANG JING-MING , LI HUI , LIU HONG , SUN CHIA-CHUNG
Published: October 2011

The controlling factors on molecular weight distribution in emulsion polymerization are investigated using dissipative particle dynamics simulations. The propagation and bi-radical termination kinetic steps are taken into account in the simulations by coupling a Monte Carlo type reaction model. We find that monomer concentration can be very efficient on controlling molecular weight distribution and plays a decisive role on the formation of high molecular weight polymers. Increasing initiator concentration can effectively reduce the polymer molecular weight while increasing the polydispersity index. Moreover, increasing polymerization rate can slightly narrow the molecular weight distribution. We also find that, by suitably tuning the surfactant chain length, it may be possible to obtain an optimal molecular weight distribution in emulsion polymerization.
THEORETICAL STUDY ON PHOTOINDUCED INTRAMOLECULAR CHARGE TRANSFER IN A NOVEL ORGANIC SENSITIZER C201
Authors: ZHOU FENGJIE , ZHANG YAPING , CAO SHUO , DING YONG , LIU SHASHA
Published: October 2011

A new organic dye (C201) composed of triarylamine unit as electron donor and anchoring unit as electron acceptor, was theoretically investigated by quantum chemical methods. We optimized the geometry of C201 with density functional theory (DFT) at B3LYP/6-311G (d) level. Densities of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), as well as the energies are listed. The excited states of the dye molecules C201 were calculated by time dependent-DFT (TD-DFT) method. Two main visible bands at 572 nm and 407 nm were mainly attributed to the electronic transition from HOMO→LUMO and HOMO-1→LUMO, respectively. 3D cube representations including transition density (TD) and charge difference density (CDD) directly visualized the character of intramolecular charge transfer of C201. The orientation and strength of transition dipole moment were showed visually using TD. Furthermore, we illustrate the orientation and results of the intramolecular charge transfer by CDD.