bluuebunny/crossref_metadata_2025 huggingface dataset:
Malignant müllerian mixed tumor (carcinosarcoma) of the fallopian tube: an immunohistochemical study of neoplastic cells
Authors: KURODA NAOTO , MORIKI TOSHIAKI , OGURI HIROYOSHI , MAEDA NAGAMASA , TOI MAKOTO , MIYAZAKI ERIKO , HIROI MAKOTO , FUKAYA TAKAO , ENZAN HIDEAKI
Published: October 2005

The patient was a 65‐year‐old woman who complained of lower abdominal pain. Salpingo‐oophorectomy and hysterectomy were performed due to suspicion of ovarian cancer. At surgery a polypoid mass was observed in the fimbria of the left fallopian tube. Histologically, proliferation of undifferentiated neoplastic cells with marked cytological atypia predominated in the tumor. Proliferation of rhabdomyoblastic cells or spindle cells, as well as adenocarcinoma arising from the mucosa of the fallopian tube, was observed. A diagnosis of malignant müllerian mixed tumor (MMMT) was made. CD10 was expressed in adenocarcinoma, undifferentiated, spindle and rhabdomyoblastic cells. Furthermore, rhabdomyoblastic cells were positive for desmin and myoglobin. Undifferentiated and spindle neoplastic cells were focally positive for ASMA and negative for h‐caldesmon. Finally, our preliminary report suggests that MMMT of the fallopian tube may contain immature smooth muscle cells or cells with the myofibroblast‐like immunohistochemical phenotype in the undifferentiated component.
Statin‐associated myopathy with normal creatine kinase levels
Authors: TRØSEID MARIUS , HENRIKSEN OLAF A. , LINDAL SIGURD
Published: October 2005

Recent reports suggest that statins may cause myopathy with normal creatine kinase levels. We describe four related patients with statin‐associated muscle symptoms and normal creatine kinase levels. In two out of the four patients (mother and son), pathological findings on EMG suggested myopathy, and muscle biopsies showed evidence of mitochondrial pathology. A third patient (daughter) had slight myopathic findings on EMG and muscle biopsy, but not enough to be classified as pathological. In a fourth patient, there were no pathological findings. Creatine kinase levels were normal and symptoms diminished after discontinuation of drugs in all four patients. Our findings are consistent with other reports of statin‐associated myopathy with normal creatine kinase levels. An inherited vulnerability, possibly a mitochondrial pathology, might cause or aggravate symptoms in some patients.
Cloning and expression of rat fucosyltransferase VII at sites of inflammation
Authors: NIITTYMÄKI JAANA , MATTILA PIRKKO , RENKONEN RISTO
Published: October 2005

The sialyl Lewis x (NeuAcα2‐3Galβ1‐4(Fucα1‐3)GlcNAc) determinants serve as ligands in the selectin‐mediated adhesion of leukocytes to activated endothelium. The final step in the sialyl Lewis x synthesis is catalyzed by α1‐3‐fucosyltransferase, which transfers fucose to sialylated type 2 chain. We report the cloning of rat α1‐3‐fucosyltransferase gene (rFUT) isolated from rat lymph node and kidney allograft. The rFUT is expressed as two splice variants, but only the long one showed enzymatic activity towards sialylated lactosamine. Also flow cytometry analysis with the sLex mAbs indicated that the cloned rFuc‐T was a functional enzyme and a member of the Fuc‐TVII family. The rFuc‐TVII mRNA expression level was strongly enhanced during acute inflammatory reaction induced by kidney allograft rejection, which could be detected by in situ hybridization and quantitative real‐time PCR.
Acutely administered melatonin is beneficial while chronic melatonin treatment aggravates the evolution of TNBS‐induced colitis
Authors: Marquez Esther , Sánchez‐Fidalgo Susana , Calvo Juan Ramón , Lastra Catalina Alarcón la de , Motilva Virginia
Published: October 2005

Abstract:  The aim of this study was to evaluate the effects of melatonin on the inflammatory response and hydroxyproline production in an experimental acute and chronic model of trinitrobenzene sulfonic (TNBS) acid‐induced colitis in Wistar rats. In the acute model, melatonin (0.5, 1, and 2 mg/kg, i.p.) was applied 48, 24, and 1 hr prior to the induction of colitis and 24 and 48 hr after; the severity of colitis was less evident in melatonin‐treated animals with significant response in the group treated with 2 mg/kg. All doses investigated significantly reduced the myeloperoxidase activity (MPO). In the chronic studies, melatonin (1 and 2 mg/kg, i.p.) was administered daily 24 hr before hapten instillation and for 7 or 21 days after TNBS; melatonin (2 mg/kg) worsened colitis evolution in the 21‐day study with a significant increase in MPO activity and tumor necrosis factor‐alpha production with respect to TNBS group. Histological slides were in concordance with macroscopic data where areas of extensive necrosis and edema, fibrosis, and absence of regenerated epithelium were observed. Moreover, the hydroxyproline determination, used as indicator of collagen production and fibrosis, also showed a marker increase. The results obtained in this experimental model showed that short‐term administration is protective while in the long term it negatively influences evolution of inflammatory colitis; therefore, the immunostimulatory effect of melatonin in some situations when given chronically, such as during inflammatory bowel disease, might lead to negative consequences.
Melatonin as a cytoskeletal modulator: implications for cell physiology and disease
Authors: Benítez‐King Gloria
Published: October 2005

Abstract:  The cytoskeleton is a phylogenetically well‐preserved structure that plays a key role in cell physiology. Dynamic and differential changes in cytoskeletal organization occur in cellular processes according to the cell type and the specific function. In neurons, microtubules, microfilaments and intermediate filament (IF) rearrangements occur during axogenesis, and neurite formation which eventually differentiate into axons and dendrites to constitute synaptic patterns of connectivity. In epithelial cells, dynamic modifications occur in the three main cytoskeletal components and phosphorylation of cytoskeletal associated proteins takes place during the formation of the epithelial cell monolayer that eventually will transport water. In pathological processes such as neurodegenerative and psychiatric diseases an abnormal cytoskeletal organization occurs. Melatonin, the main product secreted by pineal gland during dark phase of the photoperiod, is capable of influencing microfilament, microtubule and IF organization by acting as a cytoskeletal modulator. In this paper we will summarize the evidence which provides the data that melatonin regulates cytoskeletal organization and we describe recent findings, which indicate that melatonin effects on microfilament rearrangements in stress fibers are involved in the mechanism by which the indole synchronizes water transport in kidney‐derived epithelial cells. In addition, we review recent data, which indicates that melatonin protects the neuro‐cytoskeletal organization from damage caused by free radicals contributing to cell survival, in addition to the already described mechanism elicited by the indole to prevent apoptosis and to scavenge free radicals. Moreover, we discuss the implications of an altered cytoskeletal organization for neurodegenerative and psychiatric illnesses and its re‐establishment by melatonin.
Two New Saponins from Lysimachia capillipes Hemsl.
Authors: TIAN Jing‐Kui , ZOU Zhong‐Mei , XU Li‐Zhen , YANG Shi‐Lin
Published: October 2005

Abstract: To investigate the saponins from whole plants of Lysimachia capillipes Hemsl., two new saponins, named capilliposide E (1) and capilliposide F (2), were isolated. The structures of the new saponins were elucidated as 3β,22α‐dihydroxy‐16α‐acetat‐28→13‐lactone‐oleanane‐3‐O‐[β‐D‐glucopyranosyl‐(1←2)‐α‐Z‐arabinpyranoyi]‐22‐O‐β‐D‐glucopyranoside (1) and 3β, 22α‐dihydroxy‐16α‐acetat‐28‐l3‐lactone‐oleanane‐3‐O‐{[β‐D‐glucopyranosy‐(l→2)‐β‐D‐glucopyranosyl‐(l→4)]‐α‐L‐arabinpyranoyl}‐22‐O‐β‐D‐glucopyranoside (2). The structures of these compounds were determined by 1D‐ and 2D‐NMR, MS techniques, and chemical methods.

(Managing editor: Wei WANG)
The anomalous flux ratio of iron K lines in NGC 3783 and its possible Cerenkov origin
Authors: Liu D. B. , Chen L. , You J. H.
Published: October 2005

When thermal relativistic electrons with an isotropic distribution of velocities move through a dense gas region, or impinge upon the surface of a cloud of dense gas, the Cerenkov effect will produce peculiar atomic or ionic emission lines, which we call ‘Cerenkov line-like radiation’. This prediction has been verified by laboratory experiments in the optical waveband. The newly recognized line emission mechanism can find wide applications in high-energy astrophysics. The first candidates are active galactic nuclei (AGNs), e.g. Seyfert 1 galaxies, for which iron Kα at ∼6.4–6.5 keV and Kβ at ≳7.0 keV with peculiar properties have been detected in observations. The traditional ‘photoelectric absorption–fluorescence line emission’ mechanism seems insufficient to explain some of the observational properties of the iron K lines. However, the Cerenkov line-like radiation mechanism provides solutions for these puzzles. In particular, the updated observed ratio of photon number fluxes of iron K lines fobsKα/fobsKβ≈ 4.0 is very difficult to understand from the prevailing fluorescence mechanism in classical physics. A solution can be obtained when the Cerenkov line mechanism is taken into consideration. If our suggestion were further supported by observations, the conventional scenario around the central supermassive black hole of an AGN would need to be modified to accommodate a more energetic, more violent and much denser environment than previously thought.
The Influence of a Firm's Cross‐Functional Orientation on Supply Chain Performance
Authors: Eng Teck‐Yong
Published: October 2005

In today's growing complexity of global networks of supply chains and hypercompetitive business environments, firms are confronted with the need to manage supply chain activities across functions and between firms. While prior research has noted the benefits of collaboration between functional areas for enhanced supply chain performance, there is not yet empirical evidence on whether an orientation toward working collectively among different functions for a firm's supply chain could influence customer satisfaction and supply chain responsiveness. A structured questionnaire was administered to U.K.‐based food service suppliers, and 112 usable mail responses were obtained. Measures supporting cross‐functional orientation (CFO) were developed using exploratory and confirmatory factor analyses, and hypotheses were tested via path analysis. The findings show that a CFO positively affects customer satisfaction and supply chain responsiveness. The length of Internet adoption was also found to play a critical role in enhancing CFO, through positive moderating relationships with customer satisfaction and supply chain responsiveness.
CFTR, chloride concentration and cell volume: could mammalian protein histidine phosphorylation play a latent role?
Authors: Treharne K. J. , Crawford R. M. , Mehta A.
Published: October 2005

A considerable body of evidence indicates that the intracellular chloride concentration ([Cl−]i) is an important regulatory signal in epithelial ion transport. [Cl−]i regulates the open channel probability of sodium and chloride channels, the rate of chloride channel recycling to the apical membrane, cell volume homeostasis, the activity of sodium‐coupled chloride entry pathways and G‐protein activity. Cell volume goes awry in epithelial cells bearing mutant forms of the cystic fibrosis (CF) transmembrane conductance regulator protein (CFTR); however, the pathways that mediate this [Cl−]i effect at the apical membrane of polarized epithelia are unknown. Recently, we proposed a mechanism for the transduction of in vitro chloride concentration into a phosphorylation signal to proteins within the apical membrane of respiratory epithelia. Our studies show that an apically enriched plasma membrane fraction from a variety of species, including sheep, human and mouse airway, contains at least two membrane‐bound protein kinases which exhibit a number of novel properties. Firstly, the phosphate is located on histidine residues within different families of proteins; one kinase(s) utilizes GTP rather than ATP as a phosphate donor and each kinase has its own unique profile of membrane protein phosphorylation (which itself varies with anion species). Secondly, both kinases mediate Cl−‐dependent phosphorylation of an apical membrane protein around the established physiological values for [Cl−]i in airway epithelial cells (∼40 mm); associated phosphatases also alter the net phosphoprotein profile of the apical membrane. These findings are reviewed and their potential roles explored in relation to the pathogenesis of CF using the control of cell volume as a model for disrupted cellular function in CF‐affected epithelia.
Statistical Model of Extreme Shear
Authors: Larsen Gunner Chr. , Hansen Kurt S.
Published: October 2005

In order to continue cost-optimization of modern large wind turbines, it is important to continuously increase the knowledge of wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function (PDF) of turbulence driven short-term extreme wind shear events, conditioned on the mean wind speed, for an arbitrary recurrence period. The model is based on an asymptotic expansion, and only a few and easily accessible parameters are needed as input. The model of the extreme PDF is supplemented by a model that, on a statistically consistent basis, describes the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of full-scale measurements recorded with a high sampling rate. The measurements have been extracted from ”Database on Wind Characteristics” (http:∕∕www.winddata.com∕), and they refer to a site characterized by a flat homogeneous terrain. The comparison has been conducted for three different mean wind speeds in the range of 15-19m∕s, and model predictions and experimental results are consistent, given the inevitable uncertainties associated with the model as well as with the extreme value data analysis.
Postbuckling Analysis of a Wind Turbine Blade Substructure
Authors: Hermann Thomas M. , Mamarthupatti Dharmaraj , Locke James E.
Published: October 2005

Postbuckling analysis of composite laminates representative of wind turbine blade substructures, utilizing the commercial finite element software ANSYS, is presented in this paper. The procedure was validated against an existing postbuckling analysis. Three shell element formulations, SHELL91, SHELL99, and SHELL181, were examined. It was found that the SHELL181 element with reduced integration should be used to avoid shear locking. The validated procedure was used to examine the variation of the buckling behavior, including postbuckling, with lamination schedule of a laminate representative of a wind turbine blade shear web. This analysis was correlated with data from a static test. A 100% postbuckling reserve in a composite structure representative of a shear web was quantified through test and analysis. The buckling behavior of the shear web was improved by modifying the lamination schedule to increase the web bending stiffness. Modifications that improved the buckling load of the structure did not always equate to improvements in the postbuckling reserve.
Effects of aging on dynamic bulk moduli of several elastomers
Authors: Burns J. , Dubbelday P. S. , Ting R. Y.
Published: October 2005

Samples of natural rubber, butyl rubber, neoprene, and polyurethane were aged for a total of 24 months at room temperature in seawater. The dynamic bulk modulus was measured for each sample at intervals during the 2-yr aging period. Age-induced changes in the dynamic bulk moduli were relatively small in all cases, but there were distinct differences among the various types of elastomers tested. In general, aging effects appear considerably more pronounced for shear and Young's moduli than for bulk moduli. Possible reasons for this are discussed.
Viscoelastic constants for pressure release materials
Authors: Caille Gary , Jarzynski Jacek , Rogers Peter , Woodruff George W.
Published: October 2005

A comparison of experimentally and theoretically determined viscoelastic constants for closed cell neoprene rubber and corprene is presented. Both of these materials have air concentrations of greater than 50% by volume and exhibit large acoustic attenuation. The longitudinal sound speed is approximately 150 m/s for the closed cell neoprene rubber and 340 m/s for the corprene. The experimental constants determined are the complex Young's modulus and complex plane-wave modulus in the frequency range of 500 to 5000 Hz. Standard experimental techniques for measurement of these moduli are used. The experimental data are corrected for multiple internal reflections by use of the complex cepstrum signal processing technique. The theoretical predictions are based on multiple scattering models and quasistatic mean elastic field models. [Work supported, in part, by ONR Code 1125A.]
Surface waves in viscoelastic fluid
Authors: Jones H. W. , Kwan H. W. , Yeatman E.
Published: October 2005

Viscoelastic fluids will, in principle, propagate Lamb and Rayleigh waves. In these circumstances, the shear modulus is frequency dependent in both its real and imaginary parts; therefore, it might be expected that some unusual effects will occur. In this paper, the propagation of such waves by reference to the viscoelastic properties of crude oil is described. Numerical calculations showing the properties of these waves under a range of conditions are presented.
Numerical modeling techniques in underwater acoustics
Authors: Etter Paul C.
Published: October 2005

A summary of available underwater acoustic modeling techniques is presented, emphasizing those computer-implemented codes applicable principally to research in support of naval sonar design and operation. This comprehensive summary addresses three major classes of models: propagation loss, noise, and reverberation. Fifty propagation loss models are categorized according to five theoretical derivatives of the wave equation: ray theory, multipath expansion, normal mode, fast field, and parabolic approximation; further distinctions are made between range-independent and range-dependent solutions. Fourteen noise models are divided into the categories of ambient noise and beam-noise statistics; models in the latter category are further segregated according to analytic and simulation approaches. Fourteen reverberation/active sonar models are jointly described in addition to two multiple-component model operating systems; the reverberation models are distinguished according to cell and point scattering formulations. Supporting open-literature citations are provided to identify principal investigators and institutions. This summary affords a convenient baseline against which to define future developmental efforts in such areas as hybrid, 3-D, broadband, stochastic, shallow-water, and under-ice acoustic modeling.
Derivation of higher-order parabolic equations which include density variations
Authors: Knightly George H. , St. Mary Donald F.
Published: October 2005

Several approaches to the derivation of parabolic equations are explored, which include general density functions, starting from the acoustic wave equation in two and three dimensions. In particular, higher-order (wide angle) parabolic equations are presented. Also presented are finite-difference discretizations of the equations that (1) attempt to alleviate the need for special consideration of the “continuity conditions” when one fluid medium interfaces with another, and (2) specifically take into consideration such interfaces. Mathematical comparisons are made between these two approaches.
A full wave solution for propagation in horizontally stratified elastic media with full forward and backscatter
Authors: Haddad Ziad
Published: October 2005

A numerically efficient procedure for finding complete solutions to wave propagation problems in elastic media whose parameters depend on depth only, but where one of the interfaces (e.g., water/air) is allowed to vary (under some restrictions) with range, is derived from the method recently proposed by H. Schmidt and F. Jensen. This extension applies to the case where the depth at an interface expressed as a function of range is a sum of sinusoids. The roughness imposes energy coupling equations that must be satisfied by sets of wavenumber components of the pressure field, grouped according to the wavelengths of the sinusoids. The importance of the coupling depends on the amplitudes of the sinusoids, and accounts for al nonevanescent forward and backscattering. Plane-wave reflection coefficient calculations using this method agree with exact computations based on work by R. Holford [J. Acoust. Soc. Am. 70, 1116–1128 (1981)]. This procedure is further extended to allow the rough interface, say, the free surface, to move (under some restriction) with time, thus allowing a rapid complete solution of the wave equation including full Doppler effects.
Nearfield calculations from elongated objects and a comparison with the farfield form function
Authors: Werby M. F. , Norton Guy , Gaunaurd G.
Published: October 2005

It is usual to examine farfield form functions when examining scattering from submerged objects. In this study, what happens when one examines the bistatic angular distributions in the very nearfield for elongated spheroids was determined. The distance from the field is then progressively moved from the object in multiples of the semimajor axis until the results agree with the farfield form function. It is found that this does not occur until one is a distance greater than 20 times the largest diameter from the object. When one is close to the object, the calculations reflect the fact that a shadow is cast on the observer and, therefore, the pattern is rather broad close up and it narrows as one progressively moves from the object. This last effect can be obtained using a simple geometrical expression that agrees with the theoretical calculations.
Scattering from an ellipsoid submerged in the ocean
Authors: Collins Michael D. , Werby Michael F.
Published: October 2005

A time periodic source and an ellipsoid are submerged in a stratified ocean several kilometers apart. The method of matched asymptotics is used to derive an approximate expression for the field scattered from the ellipsoid. The matched asymptotics solution consists of an inner solution valid near the scatterer and an outer solution valid away from the scatterer. The two parts of the solution are matched in the region in which they are both valid. The resulting solution is composed of solutions to problems existing models can handle. The asymptotic limit applied to arrive at the result requires that the scatterer is small relative to the depth of the ocean and is away from the ocean surface and bottom. However, the method should be sufficiently robust to allow these assumptions to be relaxed greatly. This method is only weakly dependent on frequency; the frequency must be on the order of 10 Hz or greater. [Work supported by ONR and NORDA.]
Acoustic levitation at high temperatures in the microgravity of space
Authors: Rey Charles A. , Merkley Dennis R. , Hammarlund Gregory R. , Danley Thomas J.
Published: October 2005

Acoustic levitation of a small specimen is obtained in the energy well produced by a single axis arrangement consisting of a sound source and a small acoustic reflector. At high temperatures, the acoustic forces are generally insufficient to levitate a specimen except in the microgravity environment available in space. A single axis acoustic levitator (SAAL) has been built to levitate a specimen inside a high-temperature furnace where it may be heated, melted, cooled, and solidified while being positioned without physical contact. The acoustic field configuration in such a containerless processing device has been analyzed and the expected levitation or positioning forces are calculated for the specific case of the NASA-SAAL experimental hardware as flown on the Space Shuttle on the STS-61A mission. This experiment successfully levitated and processed three samples at temperatures from 600 °C to 1550 °C. Experimental data are presented and the results compared with those predicted. [Work supported by NASA.]
Eigenfrequencies of axisymmetric cavities: Numerical calculations
Authors: Woodling Arthur E. , Mehl James B.
Published: October 2005

The eigenfrequencies of axisymmetric, hard-walled acoustic cavity resonators have been calculated by using an integral-equation representation of the Helmholtz equation with Neumann boundary conditions. For axisymmetric shapes, the integral equation is one-dimensional. Numerical results have been obtained for a perfect sphere, and for slightly deformed spheres, and for cylinders with an internal sphere on axis. The results for slightly deformed spheres are in close agreement with the predictions of boundary-shape perturbation theory, from which they typically differ by less than 6 parts in 106. The results for cylinders with internal spheres are in excellent agreement with measurements [M. Barmatz et al., J. Acoust. Soc. Am. 73, 725–732 (1983)].
Stress-induced anisotropy in sediment acoustics
Authors: Stoll R. D.
Published: October 2005

A model to describe seismic wave propagation in both dry and water-saturated particulate materials is derived on the basis of the response of a regular array of like elastic spheres. The theories of Hertz and Mindlin are used to model the normal and tangential compliances at the intergranular contacts, and the overall response of the array is found to be governed by a set of nonlinear differential equations. These equations are integrated over a particular stress history that simulates the normal buildup and relief of geostatic stress (overburden pressure) in nature. Wave velocities are evaluated at various stages during this stress history and the response is found to be anisotropic with respect to both P and S wave velocities. In order to simulate the response of marine sediments, the effects of water saturation are investigated by using the compliances calculated for the dry skeletal frame in conjunction with the Biot theory. Finally, the predictions of the model are compared with recent laboratory experiments and found to be in general agreement. [Work supported by ONR, Code 1125 OA.]
Quantitative characterization of degree of coarticulation in CV tokens
Authors: Cohn Abigail C.
Published: October 2005

Languages are often assumed to show greater or lesser degrees of coarticulation [P. Ladefoged, in Papers in Linguistics and Phonetics in Memory of Pierre Delattre, edited by A. Waldman (Mouton, The Hague, 1972), pp. 273–286], yet no quantitative measure exists for characterizing degree of coarticulation. In this study, the development of a metric for degree of influence of a vowel on a preceding stop consonant has been undertaken. For each language in the study, LPC spectra were made at the burst onset of initial stops followed by a vowel. Templates were made of these spectra when the vowel was /a/. The stop spectra with other vowels were tested against these templates to determine a percent fit. Languages differ in their percent fit; a low percent fit indicates that vowels have a great effect on preceding consonants and a high percent fit indicates that they do not. Kana, a language of Nigeria which gives the auditory impression of having a high degree of coarticulation, is being compared to other languages including Russian, a language with secondary articulations. [Work supported by NSF.]
Electromagnetic basis of acoustic perception. II. Physical mechanisms
Authors: Clark John G.
Published: October 2005

A study of physical parameters leads to the conclusion that the human skull, with brain tissue included, is a cavity that will support electromagnetic standing wave fields in the frequency range between 200 MHz and 3 GHz. This frequency range coincides with allowable transitions in the rotational energy states of integral proteins that are embedded in nerve membranes. This frequency overlap permits the integral proteins to couple energy between propagating action potentials and standing electromagnetic fields within the skull. This is a crucial physical mechanism in a full theory of brain functioning which accords standing EM fields a central role in acoustic perception. All physical mechanisms will be discussed and related to biological structures in the brain. A key prediction of the theory is that the frequency of the lowest EM standing wave mode for any individual can be predicted simply with knowledge of the cephalic index. Recent measurements made on seven individuals confirm the theory. [Work sponsored by Mentec, Inc.]
Determination of ocean bottom sound-speed profiles using a modal inverse technique in a range-dependent shallow water environment
Authors: Frisk George V. , Lynch James F. , Rajah Subramaniam D.
Published: October 2005

A modal inverse technique for determining ocean bottom sound-speed profiles is applied to experimental data obtained in a range-dependent shallow water environment. The method consists of towing a cw source away from moored receivers to obtain a well-sampled measurement of the complex pressure versus range. The Hankel transform of the measured field then yields the depth-dependent Green's function versus horizontal wavenumber, which contains distinct peaks at the modal eigenvalues. The eigenvalues are used as input data to a perturbative inverse scheme that generates the sound-speed profile of the bottom. Data at 140 and 220 Hz were obtained in May 1984 in Nantucket Sound, MA in an area where the depth changed abruptly at about the midpoint of the experimental track. An associated change in bottom properties was assumed, and the concept of local modal eigenvalues yielding local geoacoustic parameters was then used to determine separate models for the two regions. Excellent agreement between the pressure fields computed for this range-dependent model using adiabatic mode theory and the experimentally measured fields is demonstrated.
Model and data comparison for bottom backscattering
Authors: Jackson Darrell R. , Briggs Kevin B.
Published: October 2005

Acoustic and geoacoustic data from two sites have been compared with a model [D. R. Jackson et al., J. Acoust. Soc. Am. 79, 1410–1422 (1986)] for bottom backscattering strength at high frequencies. At one site, the sediment was a fine sand with prominent, directional ripples. At the other site, the sediment was a mixture of clay, sand, and shell. The geoacoustic data were used to obtain values for the following model input parameters: sediment sound speed, sediment mass density, and the power spectrum for bottom microrelief. The model also requires a sediment volume scattering parameter, which was obtained by fitting backscattering data. The model generally gave good descriptions of the level and grazing angle dependence of the backscattering strength, and the results indicate that roughness scattering was dominant at the sandy site, while sediment volume scattering was dominant at the sandy site. At the sandy site, the microrelief spectrum showed appreciable anisotropy and an unusually rapid falloff with increasing spatial frequency. For this site, the backscattering model overestimated both the degree of anisotropy (none was observed) and the level of scattering at the highest frequencies. [Work supported by ONT and NORDA.]
High-resolution acoustic bottom roughness measurement in support of bottom echo interaction modeling
Authors: Dammann W. P. , Lauter C. A.
Published: October 2005

A high-resolution acoustic bottom profiler using an extremely narrow-beam, 3-MHz echo sounder was developed at the Ocean Acoustic Division of NOAA/AOML. The device was used to measure bottom roughness over a range of scales from less than 1 cm to several meters. Roughness measurements were made in the lower Chesapeake Bay area over mud, fine to medium grain sand, and course grain sand. The data produced were used to appraise the performance of an acoustic echo formation model that predicts the effects of marine bottom characteristics on a reflected acoustic pulse envelope. Major aspects of the design and use of the system, procedures for processing generated data, and examples of processed output are presented.
Modeled effects of seafloor anisotropy using the facet-ensemble method and comparison with Red Sea data
Authors: Schreiner Henry F.
Published: October 2005

Bathymetric measurements, as well as a knowledge of the formation processes involved in shaping the ocean bottom, have indicated a strong anisotropy in bottom roughness over much of the world's oceans [C. G. Fox and D. E. Hayes, Rev. Geophys. 23, 1–48 (1985)]. This anisotropy can be approximated by a ridge or trough or a series of ridges and troughs. The facet-ensemble method computes the three-dimensional complex acoustic pressure from a signal that has been scattered and reflected from this kind of surface [W. A. Kinney et al., J. Acoust. Soc. Am. 75, 183–194 (1983)]. The model has been adapted to a side-scanning sonar of frequency 3.5 kHz and horizontal and vertical beam widths of 10° and 30°, respectively. The computation is driven by a 100-ms source and sampled at a rate of 128/s. Comparisons are made with experimental data from the highly lineated Red Sea Channel. A one-to-one correspondence between the features on the echo track and the modeled results is observed. [Work supported by Office of Naval Technology.]
Active control of vibrations using externally excited piezoceramic devices
Authors: Bao X. Q. , Varadan V. K. , Varadan V. V.
Published: October 2005

The design and function of piezoceramic devices containing either one (unimorph) or two (bimorph) piezoceramic disks are described. The function of these devices is to null the transmitted displacement field or both the transmitted and reflected displacement fields when a displacement or pressure field is impressed on one side of the device. Such a device can be used to actively control vibrations of a given frequency by suitably adjusting the voltages that can be applied to one or both the disks. For the unimorph device, fairly wideband conditions of zero transmission can be achieved. For the bimorph device, voltages to the two disks are independently controlled so as to achieve simultaneously the desired conditions of zero reflection and transmission. One or both voltage sources may drain energy from the system. In each case the equivalent electric circuit can be modeled so that the current-voltage characteristics of the device can be calculated and plotted. The piezoceramics are composite in construction containing a piezoelectric phase dispersed in a nonpiezoelectric phase so that the device has the needed mechanical and electromechanical coupling coefficients.
Source models for fricative consonants
Authors: Shadle Christine H.
Published: October 2005

Source parameters for models of fricative consonants were derived from experiments using mechanical models having the profile of midsagittal x rays given in Fant [Acoustic Theory of Speech Production (Mouton, The Hague, 1970)]. By positioning a pressure probe at several points along the wall of each model's tract, it was shown that sound-generation characteristics of fricatives such as /s, ∫/ differ fundamentally from those of ç, x/ with regard to source location, source spectrum level at low frequencies, and the relationship between source spectrum amplitude and mean volume velocity. In both cases, sound is generated when turbulent air strikes relatively rigid boundaries. The angle of the boundary with respect to the flow of air is the significant factor in this case. For /s, ∫/, the obstacle is at right angles, for/ç, x/, the “obstacle,” the tract wall, is nearly parallel to the flow. Implications for vocal tract models will be discussed. [Work supported by a Hunt Fellowship awarded by the Acoustical Society, and a grant awarded by the North Atlantic Treaty Organization in 1984.]
Stress effects on stop consonant closure and release gestures
Authors: Tiede Mark K.
Published: October 2005

This study seeks to characterize the articulatory kinematics of stop consonant gestures in contrasting environments, with the aim of incorporating the results into the gesture-based approach to synthesis under development at Haskins. The CVCVC tokens drawn from the Bell x-ray micro-beam corpus have been examined, representing combinations of stress, vowel, and consonant type spoken in isolation by a female speaker of English. Measurements were taken from peaks of the vertical component of pellet displacement and velocity corresponding to consonant closure and release gestures, using the lower lip pellet for labials and the tongue root pellet for velars. The ANOVA results show that stress affects consonant gesture duration independently of coproduced vowel type, but interacts significantly with consonant type, possibly because velars compete with coproduced vowels for control of the tongue. Results also showed different results for consonant duration depending on whether the gesture occurred in the first or final syllable, which is consistent with previous studies of prepausal lengthening [D. H. Klatt, J. Phonet. 3, 129–140 (1975)]. [Work supported by NSF Grant BNS-8520709.]
Generating intonational support for discourse
Authors: Davis James Raymond
Published: October 2005

Proper intonation can make a spoken message more intelligible by marking information as old or new and communicating the hierarchical structure of information. Use of intonational variation is especially feasible in a system that synthesizes speech from an abstract representation (instead of from text) because the program already knows the structure of the information to be conveyed. This paper presents a schema for assigning pitch range and choosing pitch accents. The schema draws upon work on discourse [B. J. Grosz and C. L. Sidner, Comput. Linguist. 12, 175–204 (1986)] and on intonational meaning [J. Hirschberg and J. Pierrehumbert, Proc. 24th Meet. Assoc. Comput. Ling., 136–144 (1986)]. The model has been tested with a program which generates spoken directions for driving in Cambridge [J. Davis, Proc. Am. Voice I/O Soc.(1986)].
Acoustic phonetic features of young children's potential homophones
Authors: Allen George D. , Loeb Diane Frome , Swanson Lori , Leonard Laurence B. , Schwartz Richard G.
Published: October 2005

Homophones are different words that sound alike, e.g., “bear” and “bare.” Since young children can often hear differences they cannot speak, they may produce homophones for words they know to be different. Thus, for example, a child may hear that “bike” and “bite” are different, but if s/he cannot yet produce word-final consonants, s/he may utter both as /bai/. Two questions presently under investigation are: (1) Do young children actively seek to include or exclude such potential homophones in their early vocabulary? (2) Do children faced with such potential homophones produce subtle, subphonemic differences between them? This paper reports the results of a study aimed at answering the second of these two questions. Nine 20-month-old normally developing, English-speaking children's utterances were tape recorded for acoustic analysis. These utterances were produced in situations in which homophones were likely to result from (a) reduction of initial consonant clusters, (b) stopping of initial fricatives, or (c) deletion of final consonants. Although it is hypothesized that the most likely sources of subphonemic differentiation would be VOT [for type (a) and (b) pairs] and vowel duration [for type (c)], F0 and formant frequencies were also measured and detailed auditory phonetic analyses were performed. Results from these analyses will be discussed in terms of individual and group patterns of differentiation between potentially homophonous word pairs. [Work supported, in part, by NIH.]
Some experiments in ultrasonic pulse shaping
Authors: Lewis D. Kent , Cook Bill D.
Published: October 2005

Consider a pulse/echo ultrasonic system where the ultrasound is reflected from a large parallel reflector. Control of the shape of the output electrical signal out of this system is attempted by shaping the electronic pulse initially applied to a transducer. Analysis shows that transduction, both generation and reception, and propagation each involve differentiation. Instead of having the goal to be a unipolar pulse, the desired waveform has been chosen to be a third derivative of a Gaussian function. Initially, a Gaussian-shaped pulse is sent into the system, and it is determined by signal processing, what modifications of the driving waveform are to be made, and then this newly shaped pulse is sent to the transducer. The output is then very close to our desired third derivative of a Gaussian. Integration of the output signal three times yields a unipolar pulse of Gaussian shape with very small kurtosis.
Application of acousto-optic light modulation to the laser generation of ultrasound
Authors: Jarzynski Jacek , Berthelot Yves H.
Published: October 2005

When a laser beam passes through an acousto-optic Bragg modulator operated at constant frequency, one observes the splitting of the laser beam into several directions at angles proportional to the input frequency of the Bragg cell. Consequently, scanning of a laser beam can be achieved purely electronically by applying an FM chirped signal to a Bragg modulator. A scanning rate of about 4 mm/μs has been observed at a distance of 3 m from a Bragg cell modulated between 35 and 40 MHz in a 4-μs interval with a 1-W cw argon-ion laser source. Such a scanning technique can be used to enhance the thermal generation of ultrasonic waves in a sample illuminated with a laser beam by scanning the laser beam at a velocity that matches precisely the wave velocity in the sample. Another improvement under investigation is to use multimode optical fibers in order not only to increase the range of scanning velocities, but also to control precisely the light distribution on the surface of the sample. This noncontact method of laser generation of ultrasonic waves may find some applications in nondestructive testing.
Reliability of individual differences in lipreading
Authors: Demorest Marilyn E. , Bernstein Lynne E. , Eberhardt Silvio P.
Published: October 2005

Evaluation of the benefits of sensory aids requires stimulus materials whose psychometric characteristics are known. Generalizability theory was applied to data from two experiments to estimate measurement error arising from different materials, different talkers, and practice. Stimulus materials consisted of CID sentences and CV nonsense syllables produced by a male and a female talker and stored on video laserdisk. In experiment I, 104 normal-hearing subjects lipread the CID sentences in a single test session. Results indicate that there are substantial individual differences in lipreading performance among subjects, but that there are also systematic differences among sentences and among talkers that must be taken into account in interpreting test performance. In experiment II, 15 normal-hearing subjects who participated in an intensive training protocol involving vibrotactile supplements to lipreading were given pre- and posttests on the CID sentences and on the CV syllables. Individual differences in performance on sentences were highly stable over the training period, suggesting relatively uniform improvements due to training. Reliability over time was lower for the CV syllables and correlations between the CV and sentence materials were weak both at the pretest and posttest. [Work supported by NIH.]
Tone generation by impingement on plates by supersonic jets at various over-pressures
Authors: Powell Alan
Published: October 2005

Sonic jets at “moderate” over-pressure impinging on normal, flat, rigid plates generate intense principal tones by two distinct mechanisms [see J. Acoust. Soc. Am. Suppl. I 81, S96 (1987)]. For small plates d/D<2, (d = plate diam, D = nozzle diam) a local “feedback” occurs in the subsonic region between the stand-off shock wave and the plate, akin to that in the Hartmann air-jet generator when operated at the same pressure, with λ/D≅4(λ = acoustic wavelength). For large plates (d/D>2) an edgetone-like acoustic feedback to the nozzle occurs through the ambient atmosphere external to the jet and λ/D≅2. The unstable shock wave is excited from the downstream and upstream sides, respectively. Secondary tones also arise, occurring instead of the principal tone. Some have λ/D≅1, and are directly related to the large plate tones, even for small plates, while others are also closely related to the edgetone-like tones, but are of slightly longer wavelength. This classification enables a rational analysis and interpretation to be made of data in the sparse literature, including those for supersonic jets and jets at “high” over-pressures, and “very high” over-pressures, in which case the tone mechanisms appear to merge, with λ/D>4.
Further studies on pimel absorbers
Authors: Sridhara B. S. , Crocker Malcolm J.
Published: October 2005

Panel absorbers are very useful in reducing the noise propagated in pipes and ducts in applications where reactive mufflers cannot be used. A panel absorber is made of a rectangular panel backed by an air gap. It is believed that this is the first time detailed studies have been made on the applications of panel absorbers in pipes and ducts. Governing differential equations are derived considering the lumped and distributed spring mass systems. The ordinary and partial differential equations are solved and the expressions for the natural frequencies and the admittance of the panel absorber are obtained. Equations for the insertion loss and the transmission loss of the panel absorber are derived. Ten different types of aluminum panel absorbers have been designed, fabricated, and tested in the Sound and Vibration Laboratory at Auburn University. Panel absorber parameters such as panel thickness, panel edge support(boundary) conditions, panel absorber mounting, and panel dimensions were considered during the experiments. The location of the panel absorber along the length of the pipe was also examined. The experimental results are very encouraging. Insertion loss of the first panel absorber was 2.8 dB, whereas the insertion loss of the latest panel absorber with all the improvements is 18 dB.
A modal approach to Arctic noise modeling with implied vertical coherence
Authors: Williams R. B.
Published: October 2005

Analytic formulas of the modal attenuation coefficients appropriate for deep Arctic under-ice conditions, and modal energy partitioning of ambient noise sources are proposed. These functions can be used, together with various assumed spatial and temporal distribution functions to calculate various statistical ambient noise functions, such as vertical coherence. Vertical noise data between 15 and 50 Hz have been analyzed for model comparison, using a bandwidth of about 5 Hz. These data show that the vertical coherence usually has a sin x/x dependence, with the first zero crossing at one wavelength. Sometimes, however, zero crossing lengths of more than two wavelengths are observed. Longer correlation lengths are consistent with much of the noise energy radiating from a small region, although other interpretations are possible. Initial simple model calculations show agreement with the data. A strong nearby source of noise will cause the correlation to lengthen, while several more distant sources support the one wavelength zero crossing result. Initial sensitivity calculations, however, show that the vertical coherence function by itself is not a good validator of the model functions. Other statistics will be sought to further examine model validity. [Work supported by NORDA and NOSC 6.2 Arctic programs.]