Level variations in speech: Effect on masking release in hearing-impaired listeners

Acoustic speech is marked by time-varying changes in the amplitude envelope that may pose difficulties for hearing-impaired listeners. Removal of these variations (e.g., by the Hilbert transform) could improve speech reception for such listeners, particularly in fluctuating interference. Léger, Reed, Desloge, Swaminathan, and Braida [(2015b). J. Acoust. Soc. Am. 138, 389–403] observed that a normalized measure of masking release obtained for hearing-impaired listeners using speech processed to preserve temporal fine-structure (TFS) cues was larger than that for unprocessed or envelope-based speech. This study measured masking release for two other speech signals in which level variations were minimal: peak clipping and TFS processing of an envelope signal. Consonant identification was measured for hearing-impaired listeners in backgrounds of continuous and fluctuating speech-shaped noise. The normalized masking release obtained using speech with normal variations in overall level was substantially less than that observed using speech processed to achieve highly restricted level variations. These results suggest that the performance of hearing-impaired listeners in fluctuating noise may be improved by signal processing that leads to a decrease in stimulus level variations.National Institutes of Health (U.S.) (R01DC000117

On the nature of long-range contributions to pair interactions between charged colloids in two dimensions

We perform a detailed analysis of solutions of the inverse problem applied to experimentally measured two-dimensional radial distribution functions for highly charged latex dispersions. The experiments are carried out at high colloidal densities and under low-salt conditions. At the highest studied densities, the extracted effective pair potentials contain long-range attractive part. At the same time, we find that for the best distribution functions available the range of stability of the solutions is limited by the nearest neighbour distance between the colloidal particles. Moreover, the measured pair distribution functions can be explained by purely repulsive pair potentials contained in the stable part of the solution.Comment: 6 pages, 5 figure

Auditory and tactile gap discrimination by observers with normal and impaired hearing

Temporal processing ability for the senses of hearing and touch was examined through the measurement of gap-duration discrimination thresholds (GDDTs) employing the same low-frequency sinusoidal stimuli in both modalities. GDDTs were measured in three groups of observers (normal-hearing, hearing-impaired, and normal-hearing with simulated hearing loss) covering an age range of 21–69 yr. GDDTs for a baseline gap of 6 ms were measured for four different combinations of 100-ms leading and trailing markers (250–250, 250–400, 400–250, and 400–400 Hz). Auditory measurements were obtained for monaural presentation over headphones and tactile measurements were obtained using sinusoidal vibrations presented to the left middle finger. The auditory GDDTs of the hearing-impaired listeners, which were larger than those of the normal-hearing observers, were well-reproduced in the listeners with simulated loss. The magnitude of the GDDT was generally independent of modality and showed effects of age in both modalities. The use of different-frequency compared to same-frequency markers led to a greater deterioration in auditory GDDTs compared to tactile GDDTs and may reflect differences in bandwidth properties between the two sensory systems.National Institute on Deafness and Other Communication Disorders (U.S.) (Grant R01 DC000117

Diffusion of gold nanoclusters on graphite

We present a detailed molecular-dynamics study of the diffusion and coalescence of large (249-atom) gold clusters on graphite surfaces. The diffusivity of monoclusters is found to be comparable to that for single adatoms. Likewise, and even more important, cluster dimers are also found to diffuse at a rate which is comparable to that for adatoms and monoclusters. As a consequence, large islands formed by cluster aggregation are also expected to be mobile. Using kinetic Monte Carlo simulations, and assuming a proper scaling law for the dependence on size of the diffusivity of large clusters, we find that islands consisting of as many as 100 monoclusters should exhibit significant mobility. This result has profound implications for the morphology of cluster-assembled materials

Measurement of inclusive charged current interactions on carbon in a few-GeV neutrino beam

The SciBooNE Collaboration reports a measurement of inclusive charged current interactions of muon neutrinos on carbon with an average energy of 0.8 GeV using the Fermilab Booster Neutrino Beam. We compare our measurement with two neutrino interaction simulations: NEUT and NUANCE. The charged current interaction rates (product of flux and cross section) are extracted by fitting the muon kinematics, with a precision of 6-15% for the energy dependent and 3% for the energy integrated analyses. We also extract CC inclusive interaction cross sections from the observed rates, with a precision of 10-30% for the energy dependent and 8% for the energy integrated analyses. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. These results can be used to convert previous SciBooNE cross section ratio measurements to absolute cross section values.Comment: 21 pages, 16 figures. Accepted by Phys. Rev. D. Minor revisions to match the accepted versio

Search for Charged Current Coherent Pion Production on Carbon in a Few-GeV Neutrino Beam

The SciBooNE Collaboration has performed a search for charged current coherent pion production from muon neutrinos scattering on carbon, \nu_\mu ^{12}C \to \mu^- ^{12}C \pi^+, with two distinct data samples. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio of charged current coherent pion production to the total charged current cross section at 0.67\times 10^{-2} at mean neutrino energy 1.1 GeV and 1.36\times 10^{-2} at mean neutrino energy 2.2 GeV.Comment: 18 pages, 16 figures, Minor revisions to match version accepted for publication in Physical Review

Pelvic adhesions and pelvic pain: opinions on cause and effect relationship and when to surgically intervene

ABSTRACT Objective In the absence of definitive data, we sought to determine the consensus on the contribution of adhesions to pelvic pain. Methods Impressions about the role of adhesion location, extent, and severity of pelvic pain, were surveyed among 13 gynaecological surgeons. They were asked whether adhesions covering specific organs to a varying extent would be likely to cause pain significant enough to require pain medication, or to lead a woman to alter her normal activities, and when they would recommend surgery to reduce pelvic pain. Results Women with dense vascular adhesions covering all of the uterus but not the bowel or adnexal structures were thought to have a 49^9% likelihood of having pelvic pain; this fell to a 34^7% and 18^5% likelihood of pain if 60% or 20%, respectively, of the uterus was involved with adhesions. Similar observations were made for adhesions involving the posterior cul-de-sac and large bowel. However, adhesions involving the anterior cul-de-sac were thought to be less likely to cause pain. Women with total involvement of both tubes and ovaries with dense, vascularadhesionswerethoughttobe60^9%likelytohavepelvicpain;reduction in extent of adhesions to 50% or 25% reduced the prediction of pain to 38^5% and 21^3%, respectively. In contrast, filmy adhesions to both tubes and ovaries, were thought to cause pain in 46^9%, 26^5%, and 13^3% of women, respectively, according to extent. Half the surgeons said they would recommend surgery for patients with pain and dense adhesions involving 15% of both tubes and ovaries; 10 recommended surgery if it was known that adhesions involved 100% of bothovariesandtubes.Surgeonswereonlyslightlylesslikelytorecommendsurgery for pain relief for adhesions involving either both tubes or both ovaries or for pain associated with unilateral tubal and ovarian adhesions. For bilateral tube and ovary adhesions, surgery was equally likely to be recommended for relief of pain when adhesions were cohesive and dense; for adhesions which were filmy, surgery was less likely to be recommended. For dense adhesions involving 20%, 40%, 60%, and 80% of the uterine surface, surgery was recommended by 42%, 58%, 83% and 92% of surgeons, respectively. Posterior cul-de-sac involvement resulted in recommendation of surgery by 50%, 83%, 92%, and 100% of surgeons, respectively; however, for corresponding amounts of anterior cul-de-sac adhesions, surgery was recommended by only 17%, 33%, 67%, and 75% of surgeons. Conclusions (1) Adhesions are frequently considered to be a cause of pelvic pain; (2) the likelihood of discomfort is related to location, extent, and to a lesser degree, the severity of adhesions, and (3) adhesiolysis is thought to provide the potential for pain relief

World squid fisheries

Peer reviewedPublisher PD

The ANTARES Optical Beacon System

ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.

Violent Relaxation, Phase Mixing, and Gravitational Landau Damping

This paper proposes a geometric interpretation of flows generated by the collisionless Boltzmann equation (CBE), focusing on the coarse-grained approach towards equilibrium. The CBE is a noncanonical Hamiltonian system with the distribution function f the fundamental dynamical variable, the mean field energy H[f] playing the role of the Hamiltonian and the natural arena of physics being the infinite-dimensional phase space of distribution functions. Every time-independent equilibrium f_0 is an energy extremal with respect to all perturbations that preserve the constraints associated with Liouville's Theorem, local energy minima corresponding to linearly stable equilibria. If an initial f(t=0) is sufficiently close to some linearly stable lower energy f_0, its evolution involves linear phase space oscillations about f_0 which, in many cases, would be expected to exhibit linear Landau damping. If f(t=0) is far from any stable extremal, the flow will be more complicated but, in general, one would anticipate that the evolution involves nonlinear oscillations about some lower energy f_0. In this picture, the coarse-grained approach towards equilibrium usually termed violent relaxation is interpreted as nonlinear Landau damping. The evolution of a generic initial f(t=0) involves a coherent initial excitation, not necessarily small, being converted into incoherent motion associated with nonlinear oscillations about some equilibrium f_0 which, in general, will exhibit destructive interference.Comment: 19 pages, LaTeX, no macros, no figure