Urgency is a Non-monotonic Function of Pulse Rate

Magnitude estimation was used to assess the experience of urgency in pulse-train stimuli (pulsed white noise) ranging from 3.13 to 200 Hz. At low pulse rates, pulses were easily resolved. At high pulse rates, pulses fused together leading to a tonal sensation with a clear pitch level. Urgency ratings followed a nonmonotonic (polynomial) function with local maxima at 17.68 and 200 Hz. The same stimuli were also used in response time and pitch scaling experiments. Response times were negatively correlated with urgency ratings. Pitch scaling results indicated that urgency of pulse trains is mediated by the perceptual constructs of speed and pitch

Speech Disruption During Delayed Auditory Feedback with Simultaneous Visual Feedback

Delayed auditory feedback (DAF) regarding speech can cause dysfluency. The purpose of this study was to explore whether providing visual feedback in addition to DAF would ameliorate speech disruption. Speakers repeated sentences and heard their auditory feedback delayed with and without simultaneous visual feedback. DAF led to increased sentence durations and an increased number of speech disruptions. Although visual feedback did not reduce DAF effects on duration, a promising but nonsignificant trend was observed for fewer speech disruptions when visual feedback was provided. This trend was significant in speakers who were overall less affected by DAF. The results suggest the possibility that speakers strategically use alternative sources of feedback

Learning to Produce Speech with an Altered Vocal Tract: The Role of Auditory Feedback

Modifying the vocal tract alters a speaker’s previously learned acoustic–articulatory relationship. This study investigated the contribution of auditory feedback to the process of adapting to vocal-tract modifications. Subjects said the word /tɑs/ while wearing a dental prosthesis that extended the length of their maxillary incisor teeth. The prosthesis affected /s/ productions and the subjects were asked to learn to produce ‘‘normal’’ /s/’s. They alternately received normal auditory feedback and noise that masked their natural feedback during productions. Acoustic analysis of the speakers’ /s/ productions showed that the distribution of energy across the spectra moved toward that of normal, unperturbed production with increased experience with the prosthesis. However, the acoustic analysis did not show any significant differences in learning dependent on auditory feedback. By contrast, when naive listeners were asked to rate the quality of the speakers’ utterances, productions made when auditory feedback was available were evaluated to be closer to the subjects’ normal productions than when feedback was masked. The perceptual analysis showed that speakers were able to use auditory information to partially compensate for the vocal-tract modification. Furthermore, utterances produced during the masked conditions also improved over a session, demonstrating that the compensatory articulations were learned and available after auditory feedback was removed

Perceptual Calibration of F0 Production: Evidence from Feedback Perturbation

Hearing one’s own speech is important for language learning and maintenance of accurate articulation. For example, people with postlinguistically acquired deafness often show a gradual deterioration of many aspects of speech production. In this manuscript, data are presented that address the role played by acoustic feedback in the control of voice fundamental frequency (F0). Eighteen subjects produced vowels under a control ~normal F0 feedback! and two experimental conditions: F0 shifted up and F0 shifted down. In each experimental condition subjects produced vowels during a training period in which their F0 was slowly shifted without their awareness. Following this exposure to transformed F0, their acoustic feedback was returned to normal. Two effects were observed. Subjects compensated for the change in F0 and showed negative aftereffects. When F0 feedback was returned to normal, the subjects modified their produced F0 in the opposite direction to the shift. The results suggest that fundamental frequency is controlled using auditory feedback and with reference to an internal pitch representation. This is consistent with current work on internal models of speech motor control

Kinetic resolution of racemic {alpha}-olefins with ansa-zirconocene polymerization catalysts: Enantiomorphic site vs. chain end control

Copolymerization of racemic {alpha}-olefins with ethylene and propylene was carried out in the presence of enantiopure C1-symmetric ansa metallocene, {1,2-(SiMe2)2({eta}5-C5H-3,5-(CHMe2)2)({eta}5-C5H3)}ZrCl2 to probe the effect of the polymer chain end on enantioselection for the R- or S-{alpha}-olefin during the kinetic resolution by polymerization catalysis. Copolymerizations with ethylene revealed that the polymer chain end is an important factor in the enantioselection of the reaction and that for homopolymerization, chain end control generally works cooperatively with enantiomorphic site control. Results from propylene copolymerizations suggested that chain end control arising from a methyl group at the beta carbon along the main chain can drastically affect selectivity, but its importance as a stereo-directing element depends on the identity of the olefin

CHARACTER ASSESSMENT, GENUS LEVEL BOUNDARIES, AND PHYLOGENETIC ANALYSES OF THE FAMILY RHACOPHORIDAE:: A REVIEW AND PRESENT DAY STATUS

The first comprehensive phylogenetic analysis of the family Rhacophoridae was conducted by Liem (1970) scoring 81 species for 36 morphological characters. Channing (1989), in a reanalysis of Liem’s study, produced a phylogenetic hypothesis different from that of Liem. We compared the two studies and produced a third phylogenetic hypothesis based on the same characters. We also present the synapomorphic characters from Liem that define the major clades and each genus within the family. Finally, we summarize intergeneric relationships within the family as hypothesized by other studies, and the family’s current status as it relates to other ranoid families

Spectral Response of the Pulsationally-Induced Shocks in the Atmosphere of BW Vulpeculae

The star BW Vul excites an extremely strong radial pulsation that grows in its envelope and is responsible for visible shock features in the continuum flux and spectral line profiles emerging in the atmosphere At two phases separated by 0.8 cycles. Material propelled upwards in the atmosphere from the shock returns to the lower photosphere where it creates a second shock just before the start of the next cycle. We have obtained three nights of echelle data for this star over about 5 pulsation cycles (P = 0.201 days) in order to evaluate the effects of on a number of important lines in the spectrum, including the HeI 5875A and 6678A lines. These data were supplemented by archival high-dispersion IUE (UV) data from 1994. A comparison of profiles of the two HeI lines during the peak of the infall activity suggests that differences in the development of the blue wing at this time are due to heating and short-lived formations of an optically thin layer above the atmospheric region compressed by the infall. This discovery and the well-known decreases in equivalent widths of the CII 6578-83A doublet at the two shock phases, suggests that shock flattens the temperature gradient and produces heating in heating the upper atmosphere. Except for absorptions in the blue wings of the UV resonance lines, we find no evidence for sequential shock delays arriving at various regions of line formation of the photosphere (a "Van Hoof effect"). Phase lags cited by some former observers may be false indicators arising from varying degrees of desaturation of multiple lines, such as for the red HeI lines. In addition, an apparent lag in the equivalent width curve of lines arising from less excited atomic levels could instead be caused by post-shock cooling, followed by a rebound shock.Comment: 12 pages in Latex/MNRAS format, 9 eps-format figure

Acceleration of Wound Healing with High Voltage, Monophasic, Pulsed Current

The purpose of this study was to determine whether high voltage electrical stimulation accelerates the rate of healing of dermal ulcers. Sixteen patients with stage IV decubitus ulcers, ranging in age from 20 to 89 years, participated in the study. The patients were assigned randomly to either a Treatment Group (n = 9) or a Control Group (n = 7). Patients in the Treatment Group received daily electrical stimulation from a commercial high voltage generator. Patients in the Control Group had the electrodes applied daily but received no stimulation. The ulcers of patients in the Treatment Group healed at a mean rate of 44.8% a week and healed 100% over a mean period of 7.3 weeks. The ulcers of patients in the Control Group increased in area an average of 11.6% a week and increased 28.9% over a mean period of 7.4 weeks. The results of this study suggest that high voltage stimulation accelerates the healing rate of stage IV decubitus ulcers in human subjects

Postemergence Broadleaf Weed Control in Barley

Experiments were conducted from 1981-1983 to determine the efficacy and phytotoxicity of postemergence herbicides used to control broadleaf weeds in spring-planted barley. The following herbicides were evaluated: MCPA amine (0.37, 0.75, 1.5 lb/A, active ingredient), 2,4-D amine (0.25, 0.5, 1 lb/A), bromoxynil (0.21, 0.43, 0.86 lb/A), and metribuzin (0.11, 0.21, 0.43, 0.86 lb/A). In 1982 and 1983, three additional herbicides were included: dinoseb (0.25, 0.5, 1 Ib/A), dicamba (0.09, 0.18, 0.36 lb/A), and chlorsulfuron (0.04, 0.07, 0.14 lb/A). Weed control was determined through measurements of weed biomass in each herbicide and control plot. Phytotoxicity was measured by barley yield and test weight in all years, and additionally by germination of seed produced in 1982. None of the herbicides except dicamba in 1982 significantly reduced the yield or test weights of barley below that of the control. Common lambsquarters was the only weed present in 1981 and 1982. Bromoxynil and metribuzin provided both early-and late-season control MCPA, 2,4-D, and j dinoseb took longer to control common lambsquarters but provided adequate control by midseason. Dicamba did not control common lambsquarters as well as the other herbicides. In 1983, prostrate knotweed was also present at the study site. None of the herbicides significantly reduced the number of prostrate knotweed below that of the control Germination of 'Galt' barley was not \, affected by treating parent plants with any of the herbicides tested. The following barley varieties were screened for susceptibility to metribuzin injury in 1982: Galt, Lidal, Weal, Otal, Datal, Eero, Paavo, Otra, and Klondike. Only 'Klondike' was highly sensitive to metribuzin

Face- and Cell-Averaged Nodal-Gradient Approach to Cell-Centered Finite-Volume Method on Mixed Grids

In this paper, the averaged nodal-gradient approach previously developed for triangular grids is extended to mixed triangular-quadrilateral grids. It is shown that the face- averaged approach leads to deteriorated iterative convergence on quadrilateral grids. To develop a convergent solver, we consider cell-averaging instead of face-averaging for quadri- lateral cells. We show that the cell-averaged approach leads to a convergent solver and can be efficiently combined with the face-averaged approach on mixed grids. The method is demonstrated for various inviscid and viscous problems from low to high Mach numbers on two-dimensional mixed grids