bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental drought reduces the transfer of recently fixed plant carbon to soil microbes and alters the bacterial community composition in a mountain meadow
Authors: Fuchslueger Lucia , Bahn Michael , Fritz Karina , Hasibeder Roland , Richter Andreas
Published: October 2013

Drought affects plants and soil microorganisms, but it is still not clear how it alters the carbon (C) transfer at the plant–microbial interface. Here, we tested direct and indirect effects of drought on soil microbes and microbial turnover of recent plant‐derived C in a mountain meadow.

Microbial community composition was assessed using phospholipid fatty acids (PLFAs); the allocation of recent plant‐derived C to microbial groups was analysed by pulse‐labelling of canopy sections with 13CO2 and the subsequent tracing of the label into microbial PLFAs.

Microbial biomass was significantly higher in plots exposed to a severe experimental drought. In addition, drought induced a shift of the microbial community composition, mainly driven by an increase of Gram‐positive bacteria. Drought reduced belowground C allocation, but not the transfer of recently plant‐assimilated C to fungi, and in particular reduced tracer uptake by bacteria. This was accompanied by an increase of 13C in the extractable organic C pool during drought, which was even more pronounced after plots were mown.

We conclude that drought weakened the link between plant and bacterial, but not fungal, C turnover, and facilitated the growth of potentially slow‐growing, drought‐adapted soil microbes, such as Gram‐positive bacteria.
Improving health: structure and agency in health interventions
Authors: Choby Alexandra A. , Clark Alexander M.
Published: October 2013

Taking debates about the roles of structure and agency in health as a lens, this essay asks how Critical Realist and Feminist Intersectional approaches might inform health interventions research. Despite recognition of multiple determinants of health, health problems are often thought of as individual and interventions, in turn, target risky individual behaviours. Such approaches are rooted in a liberal model of personhood. This paper critiques enduring individualist assumptions linked to Western liberal underpinnings embedded in health interventions. It posits the need to include a robust conception of the social world in which change depends on shifting power relations, and individual agency is shaped by power as well as individual will. We propose preliminary steps for undertaking critical realist intersectional interventions research.
The nature of reality represented in high fidelity human patient simulation: philosophical perspectives and implications for nursing education
Authors: Dunnington Renee M.
Published: October 2013

Simulation technology is increasingly being used in nursing education. Previously used primarily for teaching procedural, instrumental, or critical incident types of skills, simulation is now being applied to training related to more dynamic, complex, and interpersonal human contexts. While high fidelity human patient simulators have significantly increased in authenticity, human responses have greater complexity and are qualitatively different than current technology represents. This paper examines the texture of representation by simulation. Through a tracing of historical and contemporary philosophical perspectives on simulation, the nature and limits of the reality of human health responses represented by high fidelity human patient simulation (HF‐HPS) are explored. Issues concerning nursing education are raised around the nature of reality represented in HF‐HPS. Drawing on Waks, a framework for guiding pedagogical considerations around simulation in nursing education is presented for the ultimate purpose of promoting an educative experience with simulation.
Nonlinear developmental trajectory of fear learning and memory
Authors: King Elizabeth C. , Pattwell Siobhan S. , Sun Alice , Glatt Charles E. , Lee Francis S.
Published: October 2013

The transition into and out of adolescence is a unique developmental period during which neuronal circuits are particularly susceptible to modification by experience. Adolescence is associated with an increased incidence of anxiety disorders in humans, and an estimated 75% of adults with fear‐related disorders met diagnostic criteria as children and adolescents. Conserved neural circuitry of rodents and humans has facilitated neurodevelopmental studies of behavioral and molecular processes associated with fear learning and memory that lie at the heart of many anxiety disorders. Here, we review the nonlinear developmental aspects of fear learning and memory during a transition period into and out of adolescence and provide a discussion of the molecular mechanisms that may underlie these alterations in behavior. We provide a model that may help to inform novel treatment strategies for children and adolescents with fear‐related disorders.
Formative research methods for designing culturally appropriate, integrated child nutrition and development interventions: an overview
Authors: Bentley Margaret E. , Johnson Susan L. , Wasser Heather , Creed‐Kanashiro Hilary , Shroff Monal , Fernandez Rao Sylvia , Cunningham Melissa
Published: October 2013

Nutritional and developmental insults in the first few years of life have profound public health implications, including substantial contributions to neonatal, infant, and early childhood morbidity and mortality, as well as longer term effects on cognitive development, school achievement, and worker productivity. Optimal development that can lead to the attainment of an individual's fullest potential, therefore, requires a combination of genetic capacity, adequate nutrition, psychosocial stimulation, and safe, clean physical environments. Researchers and policymakers have called for integrated child nutrition and development interventions for more than 20 years, yet there are only a handful of efficacy trials and even fewer examples of integrated interventions that have been taken to scale. While a critical component in the design of such interventions is formative research, there is a dearth of information in both the literature and policy arenas to guide this phase of the process. To move the field forward, this paper first provides an overview of formative research methods with a focus on qualitative inquiry, a description of the critical domains to be assessed (infant and young child feeding, responsive feeding, and child development), and currently available resources. Application of these methods is provided through a real‐world case study—the design of an integrated nutrition and child development efficacy trial in Andhra Pradesh, India. Recommendations for next steps are discussed, the most important of which is the need for a comprehensive set of formative guidelines for designing locally tailored, culturally appropriate, integrated interventions.
The future of tic disorder treatment
Authors: Bennett Shannon M. , Keller Alex E. , Walkup John T.
Published: October 2013

Competing theories on the etiology and treatment of chronic tic disorders and Tourette syndrome have long made the search for efficacious intervention more challenging for patients and families seeking to reduce functional impairment related to tic symptoms. These symptoms were historically posited to be either psychological in origin, leading to the long tradition of psychoanalytic psychotherapy for tics, or biological in nature, particularly since the advent of successful treatments using neuroleptic medications. Current thinking about the phenomenology of tic disorders comes from growing empirical evidence as well as advances in neuroscience and genetics research and reveals a biological vulnerability that is exacerbated by physiological arousal related to environmental or interpersonal stress. This manuscript summarizes the evolution of this knowledge base and describes current best‐practice recommendations for patients, families, and clinicians.
A specific Streptococcus mutans strain aggravates non‐alcoholic fatty liver disease
Authors: Naka S , Nomura R , Takashima Y , Okawa R , Ooshima T , Nakano K
Published: October 2013

Objective

Streptococcus mutans, a major dental caries pathogen, has shown to be associated with the aggravation of cerebral hemorrhage and inflammatory bowel diseases. In this study, we evaluated the effects of S. mutans on the development of non‐alcoholic steatohepatitis (NASH) in a mouse model.

Materials and methods

Streptococcus mutans oral strain MT8148 (serotype c) and a blood isolate TW871 (k) were used. C57BL/6J mice (6 weeks old) were fed a high‐fat diet for 4 weeks; the test strains or phosphate‐buffered saline was then intravenously administered. Mice were euthanized after 8 or 12 weeks. Whole body, extirpated liver, and visceral fat weights were determined, and histopathological evaluations of the liver specimens were performed.

Results

Mice infected with TW871 showed significantly greater body and liver weights than those administered MT8148 or phosphate‐buffered saline. Histopathological analyses revealed prominent infiltration of inflammatory cells and adipocellular deposition in livers extirpated 8 weeks after an infection with TW871; fibrosis was also observed in livers extirpated after 12 weeks.

Conclusion

These results suggest that a specific strain of S. mutans could induce NASH.
Evaluation of a global algorithm for wavefront reconstruction for Shack–Hartmann wave‐front sensors and thick fundus reflectors
Authors: Liu Tao , Thibos Larry , Marin Gildas , Hernandez Martha
Published: October 2013

Purpose

Conventional aberration analysis by a Shack–Hartmann aberrometer is based on the implicit assumption that an injected probe beam reflects from a single fundus layer. In fact, the biological fundus is a thick reflector and therefore conventional analysis may produce errors of unknown magnitude. We developed a novel computational method to investigate this potential failure of conventional analysis.

Methods

The Shack–Hartmann wavefront sensor was simulated by computer software and used to recover by two methods the known wavefront aberrations expected from a population of normally‐aberrated human eyes and bi‐layer fundus reflection. The conventional method determines the centroid of each spot in the SH data image, from which wavefront slopes are computed for least‐squares fitting with derivatives of Zernike polynomials. The novel ‘global’ method iteratively adjusted the aberration coefficients derived from conventional centroid analysis until the SH image, when treated as a unitary picture, optimally matched the original data image.

Results

Both methods recovered higher order aberrations accurately and precisely, but only the global algorithm correctly recovered the defocus coefficients associated with each layer of fundus reflection. The global algorithm accurately recovered Zernike coefficients for mean defocus and bi‐layer separation with maximum error <0.1%. The global algorithm was robust for bi‐layer separation up to 2 dioptres for a typical SH wavefront sensor design. For 100 randomly generated test wavefronts with 0.7 D axial separation, the retrieved mean axial separation was 0.70 D with standard deviations (S.D.) of 0.002 D.

Conclusions

Sufficient information is contained in SH data images to measure the dioptric thickness of dual‐layer fundus reflection. The global algorithm is superior since it successfully recovered the focus value associated with both fundus layers even when their separation was too small to produce clearly separated spots, while the conventional analysis misrepresents the defocus component of the wavefront aberration as the mean defocus for the two reflectors. Our novel global algorithm is a promising method for SH data image analysis in clinical and visual optics research for human and animal eyes.
Reliability and validity of a Brief Self‐rated Scale of Health Condition with Acute Schizophrenia
Authors: Ohata Hisanori , Yotsumoto Kayano , Taira Masaru , Kochi Yoshiro , Hashimoto Takeshi
Published: October 2013

Aim

The aim of this study was to develop a new Brief Scale of Self‐rated Health Condition with Acute Schizophrenia (BsHAS) and to examine its reliability, validity and correlation to psychiatric symptoms.

Methods

We examined the reliability and validity of the BsHAS consisting of four items (physical health condition, mood, interpersonal fatigue and interest) for 199 inpatients with acute schizophrenia and compared the patients’ subjective health conditions as assessed by the BsHAS with their objective psychiatric symptoms.

Results

Cronbach's α coefficient was 0.79, indicating that the reliability of the scale was sufficient. These four items chosen from the previous studies were approved by an expert panel, which suggested that the scale has content validity. The BsHAS total score was significantly improved at discharge. However, the effect size was only −0.24. In particular, improvement was not recognized in the interpersonal fatigue item. These findings suggest that some patients weredischarged without realizing the improvement of their health condition. The patients answered all questions without subsequently showing deteriorating symptoms, suggesting that the scale can be applied to acute‐phase patients with schizophrenia. No obvious relation was recognized between the patients’ subjective health condition as assessed by the BsHAS and their objective psychiatric symptoms. This result suggests that the BsHAS can provide additional information to the objective assessment of psychiatric symptoms.

Conclusion

These results show that the BsHAS can help psychiatric professionals to know patients’ subjective health conditions, and that the longitudinal use of this scale may be useful for evaluating the degree of recovery from schizophrenia.
Contribution of baseline body mass index and leptin serum level to the prediction of early weight gain with atypical antipsychotics in schizophrenia
Authors: Cortés Benjamín , Bécker Joemir , Mories Álvarez María Teresa , Marcos Ana I. Sánchez , Molina Vicente
Published: October 2013

Aim

This study investigated whether biochemical parameters add predictive information concerning risk for weight gain associated with treatment with atypical antipsychotics (AP) to that provided by baseline weight.

Methods

Weight changes were assessed in 25 patients with schizophrenia after 3–6 months of treatment. These patients were started on AP monotherapy owing to a first psychotic episode or resumed treatment after at least a 6‐month period of abandonment. Anthropometric and biochemical data were collected and analyzed as predictors of early weight change.

Results

The baseline biochemical and anthropometric data were not significantly higher in the patients than in the healthy participants. During follow up, the patients had significant increases in body mass index and total cholesterol and apolipoprotein B level. The baseline weight and leptin level were predictive of weight gain during follow up, with an inverse association in both cases.

Conclusion

Baseline weight and leptin level may help to assess the risk of early weight gain with AP.
Effect of Laser Phototherapy on Enzymatic Activity of Salivary Glands of Hamsters Treated with 5‐Fluorouracil
Authors: Campos Luana , Nicolau José , Arana‐Chavez Victor E. , Simões Alyne
Published: October 2013

The chemotherapeutic agent 5‐Fluorouracil (5‐FU) can induce salivary gland hypofunction (SGH); however, previous studies did not reach final conclusions on the influence of this drug on glandular tissue. Thus, the aim of this study was to investigate the effect of 5‐FU on submandibular (SMs) and sublingual glands (SLs), as well as, the effect of laser phototherapy (LPT) on SGH induced by 5‐FU. Eighty‐five hamsters were divided into three groups: control (C), chemotherapy (CT) and laser (L), and the SGH was induced by two injections of 5‐FU in groups CT and L. The irradiation was performed using a diode (λ780 nm/20 mW/5 J cm−2/0.2 J and 10 s per point/spot size of 0.04 cm2) and applied daily. On the euthanasia day, SMs and SLs were removed and biochemical analyses were carried out. The lactate dehydrogenase activity was increased in group CT when compared with group C for SLs and SMs (P < 0.05). In addition, the peroxidase and catalase activities were increased and superoxide dismutase was decreased by 5‐FU (P < 0.05). However, LPT appears to be a protective mechanism against oxidative stress, tending to alter the activity of these antioxidant enzymes, suggesting LPT as a promising therapy to modulate the 5‐FU harmful effect.
Accurate Confidence Interval Estimation of Small Area Parameters Under the Fay–Herriot Model
Authors: Diao Lixia , Smith David D. , Datta Gauri Sankar , Maiti Tapabrata , Opsomer Jean D.
Published: October 2013

Small area estimation has long been a popular and important research topic due to its growing demand in public and private sectors. We consider here the basic area level model, popularly known as the Fay–Herriot model. Although much of current research is predominantly focused on second order unbiased estimation of mean squared prediction errors, we concentrate on developing confidence intervals (CIs) for the small area means that are second order correct. The corrected CI can be readily implemented, because it only requires quantities that are already estimated as part of the mean squared error estimation. We extend the approach to a CI for the difference of two small area means. The findings are illustrated with a simulation study.
Prospective analysis of intrinsic and extrinsic risk factors on the development of Achilles tendon pain in runners
Authors: Hein T. , Janssen P. , Wagner‐Fritz U. , Haupt G. , Grau S.
Published: October 2013

There are currently no generally accepted, consistent results that clearly characterize factors causing Achilles tendon pain (AT) in runners. Therefore, we carried out a prospective study to evaluate the multifactorial influence of clinical, biomechanical (isometric strength measurements and three‐dimensional kinematics) and training‐related risk factors on the development of AT. Two hundred sixty‐nine uninjured runners were recruited and underwent an initial examination. One hundred forty‐two subjects completed their participation by submitting training information on a weekly basis over a maximal period of 1 year. Forty‐five subjects developed an overuse injury, with 10 runners suffering from AT. In an uninjured state, AT runners already demonstrated decreased knee flexor strength and abnormal lower leg kinematics (sagittal knee and ankle joint) compared with a matched control group. A relationship between years of running experience or previous overuse injuries and the development of new symptoms could not be established. The interrelationship of biomechanical and training‐specific variables on the generation of AT is evident. A combination of alterations in lower leg kinematics and higher impacts caused by fast training sessions might lead to excessive stress on the Achilles tendon during weight bearing and thus to AT in recreational runners.
Family planning in Guinea: a need for better public commitment
Authors: Delamou Alexandre , Koivogui Akoi , Dubourg Dominique , Delvaux Thérèse
Published: October 2013

Objective

To describe the evolution of family planning (FP) in Guinea and to identify strengths, weaknesses, opportunities and threats of the current FP programme.

Methods

Descriptive study of the evolution of FP in Guinea between 1992 and 2010. First, national laws as well as health policies and strategic plans related to reproductive health and family planning were reviewed. Second, FP indicators were extracted from the Guinean Demographic and Health Surveys (1992, 1999 and 2005). Third, FP services, sources of supply and data on FP funding were analysed.

Results

Laws, policies and strategic plans in Guinea are supportive of FP programme and services. Public and private actors are not sufficiently coordinated. The general government expenditure on health has remained stable at 6–7% between 2005 and 2011 despite a doubling of total expenditures on health, and contraceptives are supplied by foreign aid. Modern contraceptive prevalence slightly increased from 1.5% in 1992 to 6.8% in 2005 among women aged 15–49.

Conclusion

A stronger national engagement in favour of repositioning FP should result in improved government funding of the FP programme and the promotion of long‐acting and permanent methods.
Viral Subversion of Nucleocytoplasmic Trafficking
Authors: Yarbrough Melanie L. , Mata Miguel A. , Sakthivel Ramanavelan , Fontoura Beatriz M. A.
Published: October 2013

Trafficking of proteins and RNA into and out of the nucleus occurs through the nuclear pore complex (NPC). Because of its critical function in many cellular processes, the NPC and transport factors are common targets of several viruses that disrupt key constituents of the machinery to facilitate viral replication. Many viruses such as poliovirus and severe acute respiratory syndrome (SARS) virus inhibit protein import into the nucleus, whereas viruses such as influenza A virus target and disrupt host mRNA nuclear export. Current evidence indicates that these viruses may employ such strategies to avert the host immune response. Conversely, many viruses co‐opt nucleocytoplasmic trafficking to facilitate transport of viral RNAs. As viral proteins interact with key regulators of the host nuclear transport machinery, viruses have served as invaluable tools of discovery that led to the identification of novel constituents of nuclear transport pathways. This review explores the importance of nucleocytoplasmic trafficking to viral pathogenesis as these studies revealed new antiviral therapeutic strategies and exposed previously unknown cellular mechanisms. Further understanding of nuclear transport pathways will determine whether such therapeutics will be useful treatments for important human pathogens.
Numerical Modeling of Flow Through Phloem Considering Active Loading
Authors: Jackie Sze Tsun-kay , Liu Jin , Dutta Prashanta
Published: October 2013

Transport through phloem is of significant interest in engineering applications, including self-powered microfluidic pumps. In this paper we present a phloem model, combining protein level mechanics with cellular level fluid transport. Fluid flow and sucrose transport through a petiole sieve tube are simulated using the Nernst–Planck, Navier–Stokes, and continuity equations. The governing equations are solved, using the finite volume method with collocated storage, for dynamically calculated boundary conditions. A sieve tube cell structure consisting of sieve plates is included in a two dimensional model by computational cell blocking. Sucrose transport is incorporated as a boundary condition through a six-state model, bringing in active loading mechanisms, taking into consideration their physical plant properties. The effects of reaction rates and leaf sucrose concentration are investigated to understand the transport mechanism in petiole sieve tubes. The numerical results show that increasing forward reactions of the proton sucrose transporter significantly promotes the pumping ability. A lower leaf sieve sucrose concentration results in a lower wall inflow velocity, but yields a higher inflow of water due to the active loading mechanism. The overall effect is a higher outflow velocity for the lower leaf sieve sucrose concentration because the increase in inflow velocity outweighs the wall velocity. This new phloem model provides new insights on mechanisms which are potentially useful for fluidic pumping in self-powered microfluidic pumps.
Sediment Transport Calculation Considering Laminar and Turbulent Resistance Forces Caused by Infiltration/Exfiltration and Its Application to Tsunami-Induced Local Scouring
Authors: Nakamura Tomoaki , Mizutani Norimi
Published: October 2013

A sediment transport calculation was proposed, which consistently considered the influence of laminar and turbulent resistance forces caused by infiltration/exfiltration. From a comparison of the nondimensional bed–load sediment transport rate, it was found to be essential to consider both laminar and turbulent resistance forces when formulating the influence of infiltration/exfiltration in sediment transport calculations. A three-dimensional coupled fluid–structure–sediment interaction model was improved using the proposed sediment transport calculation, and applied to tsunami-induced local scouring around an inland structure. Numerical results showed that consideration of infiltration/exfiltration improved the computational accuracy of the prediction of a scour hole formed around the seaward edge of the structure, and accordingly the improved model could capture the evolution of the scour hole with sufficient accuracy. This suggests that the improved model should be a useful tool for assessing tsunami-induced local scouring.
Visualization methods of direct and early reflection sounds in small enclosures
Authors: Koga Chiaki , Omoto Akira , Ikeda Atsuro , Nakahara Masataka , Tanaka Natsu , Nakagawa Hiroshi
Published: October 2013

Many parameters exist for evaluating large sound fields such as concert halls. However, it is difficult to apply those parameters for evaluation of a small room such as a recording studio because of their different sound fields. Widely useful common parameters have not been established. Moreover, early reflections are important in small rooms for determining spatial acoustic impressions. Therefore, various methods that visualize spatial acoustic information obtained by early reflection in rooms are proposed. For this study, sound fields (a music studio and a filmmaking studio) were measured using three kinds of different techniques: instantaneous intensity, mean intensity, and a sphere-baffled microphone array. This report compares the information of sound source directions obtained using these methods. Results show that every method can estimate the position of sound sources and important reflections with high accuracy. In the future, we shall propose a method that visualizes spatial acoustic information more precisely by combining the methods and establishing acoustic parameters that are available for evaluating and designing small rooms.
A consideration of the measurement time interval for obtaining a reliable equivalent level of noise from expressway
Authors: Maruyama Mitsunobu , Sone Toshio
Published: October 2013

The level of road traffic noise LAeq,T greatly depends on the maximum level during the measurement time interval tau, and the maximum level often appears at the moment when two consecutive heavy vehicles pass through the point adjacent to the observation point. A mathematical model is proposed for simulating the variation in traffic noise, especially from the point of heavy vehicles with passing. The mean time interval between a pair of two consecutive heavy vehicles with the minimum allowable distance is obtained from time-series data and the mean recurrence time hij which can be calculated from the transition matrix P[pij]. The comparative study is made among the numbers of heavy vehicles from 25 to 300 [vehicles/hour] in traffic flow and the observation distances of 40 to 200 m from the road. The result shows that the measurement time interval required for the acquisition of reliable data is three to four times as long as tau or hij.
New developments in transient elastography
Authors: Fink Mathias , Tanter Mickael , Sinkus Ralph , Montaldo Gabriel
Published: October 2013

An ultra-high-rate ultrasonic scanner has been developed that can give 5000 ultrasonic images per second of the body. With such a high frame rate, the propagation of transient shear waves can be followed, and from the spatio-temporal evolution of the displacement fields, various inversion algorithms allow us to recover the shear modulus map. A discussion on the various inversion algorithms will be presented. In order to obtain unbiased shear elasticity map, different configurations of shear sources induced by radiation pressure of focused transducer arrays are used. Both 2-D and 3-D imaging can obtained with this technique. In vitro and in vivo results on breast will be presented that demonstrate the interest of elasticity imaging with transient elastography.
Spectral characteristics of breast vibro-acoustography images
Authors: Alizad Azra , Whaley Dana H. , Urban Mathew , Kinnick Randall R. , Greenleaf James F. , Fatemi Mostafa
Published: October 2013

Vibro-acoustography image is a function of the dynamic characteristics of the object at the vibration (difference) frequency (df). The dynamic characteristic of tissue is closely related to pathology. Therefore, it is important to evaluate image features versus df. Here, the influence of df on breast vibro-acoustography images is studied by scanning human breast at various df values ranging from 20 to 90 kHz. The subjects were chosen from a group of volunteers with different breast abnormalities. Images were compared subjectively to study image features and the appearances of breast lesions versus df. It is demonstrated that having a collection of images of the same tissue at different df values generally provides a better perception of the tissue structure and improves lesion identification. In most cases, higher df resulted in a higher signal-to-noise ratio and thus a higher image quality. Finally, a frequency-compounded images was obtained by calculating the weighted sum of images at different df values. It is demonstrated that image compounding normally improves visualization of breast tissue and abnormalities. [Work supported by NIH Grant EB-00535 and Grant BCTR0504550 from the Susan G. Komen Breast Cancer Foundation. Disclosure: Parts of the techniques used here are patented by MF and JFG.]
Dynamic radiation force of acoustic waves on solid elastic spheres
Authors: Silva Glauber T.
Published: October 2013

The present study concerns the dynamic radiation force on solid elastic spheres exerted by a plane wave with two frequencies (bichromatic wave) considering the nonlinearity of the fluid. Our approach is based on solving the wave scattering for the sphere in the quasilinear approximation within the preshock wave range. The dynamic radiation force is then obtained by integrating the component of the momentum flux tensor at the difference of the primary frequencies over the boundary of the sphere. Effects of the fluid nonlinearity play a major role in dynamic radiation force, leading it to a regime of parametric amplification. The developed theory is used to calculate the dynamic radiation force on three different solid spheres (aluminum, silver, and tungsten). The obtained spectrum of dynamic radiation force presents resonances with larger amplitude and better shape than those exhibited in static radiation force. Applications of the results to some elasticity imaging techniques based on dynamic radiation force will be presented.
Ultrasonic measurement of displacement distribution inside an object caused by dual acoustic radiation force for evaluation of muscular relax property due to acupuncture therapy
Authors: Odagiri Yoshitaka , Hasegawa Hideyuki , Kanai Hiroshi
Published: October 2013

Many studies have been carried out on the measurement of mechanical properties of tissues by applying an ultrasound-induced acoustic radiation force. To assess mechanical properties, strain of an object must be generated. However, one radiation force is not sufficient because it also causes translational motion when the object is much harder than surrounding medium. In this study, two cyclic radiation forces are applied to a muscle phantom from two opposite horizontal directions so that the object is cyclically compressed in the horizontal direction. As a result, the object is vertically expanded due to the incompressibility. The resultant vertical displacement is measured using ultrasound. Two concave ultrasonic transducers for actuation were both driven by sums of two continuous sinusoidal signals at two slightly different frequencies of 1 MHz and (1M+5) Hz. Displacement, which fluctuates at 5 Hz, was measured by the ultrasonic phased tracking method proposed by our group. Results indicated that the surface of the phantom was cyclically actuated with an amplitude of a tenth of a few micrometers, which well coincided with that measured with laser vibrometer. In addition, upward and downward displacements at the surface and deeper region were found during the increase phase of radiation forces. Such displacements correspond to the horizontal compression.
Micromachined microphones with diffraction-based optical interferometric readout
Authors: Degertekin F. Levent , Hall Neal A. , Bicen Baris
Published: October 2013

A diffraction-based optical method for integrated interferometric detection of micromachined microphone diaphragm displacement is described. With multichip optoelectronics integration, this approach yields highly sensitive optical microphones in mm-cube volumes. Since the microphone sensitivity does not depend on capacitance, this method changes the paradigm for the backplate and gap structure design. As a result, one can use millimeter size diaphragms to achieve wide frequency response and low thermal mechanical noise levels characteristic of precision measurement microphones. Furthermore, the electrical port of the device, which is freed by optical detection, is used for electrostatic actuation of the microphone diaphragm to tune microphone sensitivity and to generate self-characterization signals. Prototype optical microphone structures have been fabricated using Sandia National Laboratories’ silicon based SwIFT-LiteTM process. Measurements on these diaphragms show an A-weighted diaphragm displacement noise of 2.4 pm and flat electrostatic response up to 20 kHz. These results indicate the feasibility of realizing measurement microphones with 1.5-mm-diam diaphragms, 15-dBA internal noise, and 40-kHz bandwidth. Application of the detection method in a bio-inspired directional microphone for hearing aids is also discussed. [Work partially supported by NIH Grant 5R01DC005762-03, Sensing and Processing for Hearing Aids.]
Piezoelectret microphones: A new and promising group of transducers
Authors: Sessler Gerhard M. , Hillenbrand Joachim
Published: October 2013

Piezoelectret microphones, first described a few years ago, are transducers based on the strong longitudinal piezoelectric effect of charged cellular polymers. Such microphones have recently been improved in two respects: Firstly, an expansion process was used to increase the piezoelectric d33 coefficients of cellular polypropylene (PP) films in the audio frequency range up to 600 pC/N and, secondly, stacking of several films was applied to increase the microphone sensitivity. Transducers with six films now show open-circuit sensitivities of up to 15 mV/Pa, comparable to that of electret microphones. Other characteristics of piezoelectret microphones are their low equivalent noise level of about 26 dB(A) and the very small total harmonic distortion of less than 0.1% at 140 dB SPL. The piezoelectric activity of the PP films and the microphone sensitivities are stable at room temperature but start to decay above 50°C. Recently, directional piezoelectret microphones with various directional characteristics have been designed. Major advantages of piezoelectret microphones are their simple design, their low harmonic distortion, and their wide frequency range extending into the ultrasonic region.
Expansion of frequency range for piezoelectric loudspeakers by new transducer construction
Authors: Ohga Juro
Published: October 2013

Although simple construction of piezoelectric loudspeakers engenders various merits, expansion of its working frequency range to the very low region is difficult because the mechanically stiff characteristics of conventional piezoelectric ceramic diaphragms prevent their large amplitude operation. This paper proposes two sorts of new piezoelectric loudspeaker construction that are suitable for low-frequency signal radiation. One idea is the use of a tuck-shape diaphragm by a PVDF polymer film bimorph. It has large surface area with a very low resonant frequency. Resonant frequencies and sensitivity frequency characteristics are examined, and control methods of local diaphragm bending are discussed. The other idea is the use of continuous revolution of a piezoelectric ultrasonic motor. It produces a completely controlled large output force because its output mechanical impedance is much greater than that of any conventional transducer or motor. An ultrasonic motor, whose stator is connected to a direct-radiator loudspeaker cone by a rod and whose rotor is burdened by a heavy metal ring, rotates with a constant velocity. Modulation of the velocity by using an audio signal imparts a driving force to the diaphragm because the heavy ring tends to keep a constant velocity. Experimental models suggest that this construction is useful.
Modal array signal processing using circular microphone arrays applied to acoustic source detection and localization problems
Authors: Teutsch Heinz , Kellermann Walter
Published: October 2013

Many applications of acoustic signal processing rely on estimates of several parameters present in the observed acoustic scene such as the number and location of acoustic sources. These parameters have been traditionally estimated by means of classical array signal processing (CASP) algorithms using microphone arrays. Algorithms for parameter estimation solely based on the paradigm of CASP often suffer from the narrowband assumption underlying the signal model. This restriction limits their usability when wideband signals, such as speech, are present in the wave field under observation. We investigate the parameter estimation problem by applying the notion of wave field decomposition using baffled circular microphone arrays. The obtained wave field representation is used as the basis for ‘‘modal array signal processing algorithms.’’ It is shown that by applying the notion of modal array signal processing, novel algorithms can be derived that have the potential to unambiguously detect and localize multiple simultaneously active wideband sources in the array’s full field-of-view. Performance evaluations by means of simulations, measurements, and real-time case studies are presented.
Development of multichannel optical sensor and visualization of vibration distribution
Authors: Hasegawa Jun , Kobayashi Kenji
Published: October 2013

A multi-channel optical sensor system was developed to measure vibrations simultaneously with high spatial resolution. As sensor elements, optical displacement sensor units were developed not to disturb the natural vibration. Each sensor unit, which consists of the optical fiber bundle and focusing lens, can detect the displacement of the object as the variation of the reflected light power. The sensor unit has a displacement resolution of 10 nm, a dynamic range of more than 90 dB, and a frequency band width of up to 80 kHz. Up to 64 sensor units can be arrayed as one sensor head, which realizes the simultaneous measurement of vibration distribution with the high spatial resolution of 4 mm. A calibrating function under the measurement circumstances was developed. Under calibration mode, the sensor array head is moved by a linear actuator, while the vibration of the object is stopped. Thus the calibrated data of each sensor unit can be obtained for the displacement magnitude. Measured vibration distributions can be monitored as the three-dimensional animations. With the system developed, several actuators for vibratory micro-injection were measured, and the system could reveal their detailed vibration distributions and could detect the existence of a failure portion of some actuator.
Best practices for auditory alarm design in space applications
Authors: Begault Durand , Godfroy Martine
Published: October 2013

This presentation reviews current knowledge in the design of auditory caution and warning signals, and sets criteria for development of ‘‘best practices’’ for designing new signals for NASA’s Crew Exploration Vehicle (CEV) and other future spacecraft, as well as for extra-vehicular operations. A design approach is presented that is based upon cross-disciplinary examination of psychoacoustic research, human factors experience, aerospace practices, and acoustical engineering requirements. Existing alarms currently in use with the NASA Space Shuttle flight deck are analyzed and then alternative designs are proposed that are compliant with ISO 7731 (‘‘Danger signals for work places Auditory Danger Signals’’) and that correspond to suggested methods in the literature to insure discrimination and audibility. Parallel analyses are shown for a sampling of medical equipment used in surgical, periop, and ICU contexts. Future development of auditory sonification techniques into the design of alarms will allow auditory signals to be extremely subtle, yet extremely useful in subtly indicating trends or root causes of failures. [Work funded by NASA’s Space Human Factors Engineering Project.]
Without low-pass filter for the 1-bit digital amplifier
Authors: Masuda Kiyoshi , Yamasaki Yoshio
Published: October 2013

SHARP collaborated with Waseda University from 1990 for 1-bit digital technology. SHARP had started to receive an order for the 1-bit digital amplifier ‘‘SM-SX100’’ on 20 August 1999. Until today, we have introduced the 1-bit digital amplifier for audio, flat panel TV (LCD TV), and PC. These 1-bit amplifiers provided low-pass filter for the final stage, which is provided after 1-bit digital switching. We have to achieve more good sound and reduce deterioration of this low-pass filter. We have introduced new 1-bit digital amplifier without this low-pass filter beginning this April. This means we controlled the 1-bit digital signal to directly operate the speaker. We have proved a better effect for sound to compare the new 1-bit digital amplifier with the PWM switching amplifier, the A-class amplifier and the 1-bit digital amplifier with low-pass filter. If we do not measure any improvement for this new 1-bit digital amplifier, it has large radiation noise. We had achieved a reduction to the limit level of FCC, Denanhou, etc.
Perceptual acoustics of consonance and disssonance in multitimbral triads
Authors: Kendall Roger , Vassilakis Pantelis
Published: October 2013

Most studies of consonance and dissonance assume a singular spectrum for the constituent intervals of a dyad. Recently, the principal author conducted experiments evaluating triads consisting of digitally mixed combinations drawn from the MUMS single-note natural-instrument recordings. Results indicated that the main effect of ratings for consonance and dissonance correlated well with studies using artificial signals. However, interaction effects suggested perceptual differences related to the timbral differences across combinations. The present experiment evaluates perceptual and acoustical variables of the ten possible triadic combinations created with C4 as the lower and the ten with C5 as the upper notes. UCLA wind ensemble performers on oboe, flute, and clarinet, combinations designed to span timbral space, were digitally recorded. Analyses include perceptual ratings of consonance and dissonance, similarity, as well as acoustical analysis of roughness using a recently developed model. Since natural performances of any type vary in fundamental frequency, additional experiments will employ emulated oboe, flute, and clarinet (using the Kontakt Silver synthesizer in Sibelius 4) as well as purely synthetic stimuli, in order to ascertain the relationship of time-variant spectral properties to consonance, dissonance, and perceived similarity.
Further spectral correlations of timbral adjectives used by musicians
Authors: Disley Alastair C. , Howard David M. , Hunt Andrew D.
Published: October 2013

As part of a project to develop a synthesis interface which nontechnical musicians should find intuitive, the adjectives musicians use to describe timbre have been studied in a large-scale listening test covering the timbre space of Western orchestral instruments. These were refined in previous work by the authors (A. C. Disley et al. ‘‘Spectral correlations of timbral adjectives used by musicians,’’ J. Acoust. Soc. Am. 119, 3333, (2006)] to a set of ten words which had good common understanding and discrimination between the samples (bright, clear, dull, gentle, harsh, nasal, percussive, ringing, thin, and warm). To help explore potential relationships between these adjectives and spectral features, 20 listeners participated in a further listening experiment, comparing samples in pairs to produce dissimilarity data. Multidimensional scaling produced dimensions which were compared with a large number of spectral and time-domain analyses of the stimuli, suggesting a number of significantly correlated spectral cues with some of the adjectives. These results are compared with previous studies by the authors and others, showing both similarities and differences, suggesting that collective consideration of timbral adjectives is more likely to result in simultaneously applicable theories of acoustic correlates than individual consideration of words.
Measurements of the impact sound of golf clubs and risk of hearing impairment
Authors: Kurakata Kenji
Published: October 2013

The ball-impact sounds of golf clubs with metal heads and of a club with a wood head were measured to investigate their different acoustic properties. Hitting was executed using either a swing machine or a human player. Results of these analyses showed that the metal-head clubs generated sounds around 100 dB (LpA,Fmax). This level was 5–15 dB higher than that of the wood-head club. The sounds of the metal-head clubs had greater power in the high-frequency region of 4 kHz and above compared to the wood-head club, which particularly increased the overall sound levels. These results suggest that it would be desirable to develop a metal head with pleasant sound qualities, keeping the sound level lower to minimize hearing damage. Some of these measurement data were published in Japanese in a previous paper [K. Kurakata, J. INCE/J 26, 60–63 (2002)].
Sleep disturbance caused by shooting sounds
Authors: Vos Joos
Published: October 2013

In the present study relations between the sound level of shooting sounds and the probability of behaviorally confirmed noise-induced awakening reactions were determined. The sounds were presented by means of loudspeakers in the bedrooms of 30 volunteers. The shooting sounds had been produced by a small and a medium-large firearm, and the stimuli consisted of individual bangs or volleys of ten isolated or partly overlapping impulses. Aircraft sound was included as a reference source. The sounds were presented during a 6-h period that started 75 min after the beginning of the sleeping period. The time period between the various stimuli varied between 12 and 18 min, with a mean of 15 min. To cope with at least a relevant portion of habituation effects, each subject participated in 18 nights to be completed within 4 weeks. Preliminary results are presented both for the awakening reactions described above, and for various other dependent variables collected with the help of an actimeter or determined by means of subjective rating scales. [Work supported by the Dutch Ministry of Defense.]
Sports acoustics: Using sound from resonant shells, vibrating cylinders, strumming shafts, and water impact to evaluate athletic performance
Authors: Browning David G. , Scheifele Peter M.
Published: October 2013

The sound from equipment used and/or specific acts during athletic competition, such as hitting a baseball with an aluminum bat, carries beyond the playing field and can provide a nonobtrusive method to evaluate athletic performance—such as where on the bat the ball was hit. Standardized equipment guarantees repeatability, for example, every volleyball resonates at the same frequency. Each major sport can have unique noise interference which in some circumstances can be overwhelming, and the distance from the sound source can vary significantly during a game. Still, it will be shown that useful performance information can be obtained under realistic conditions for at least the following sports: volleyball, softball, baseball, golf, swimming and diving, soccer, and football.