Consequence Of Overlap Research Articles

Potential Causes and Consequences of Overlap in Talk between Speakers with Parkinson’s Disease and Their Familiar Conversation Partners

Parkinson's disease (PD) can cause both motor speech and cognitive deficits, with those affected perceiving a negative effect on their everyday experiences of communication. One specific concern reported by people with PD is that people "talk over" them. Psychosocial reactions to communication changes in PD are highly individualized and do not correlate strongly with measures of disease severity. With the aim of developing a better understanding of the individual's everyday experience of being talked over, this study uses Conversation Analysis to examine videoed instances of naturally occurring overlapping talk. Two phenomena emerge. First, aspects of speech specific to PD can cause overlap, which in turn leads to the need for repair. Second, opportunities to repair disordered talk, further compromised in terms of intelligibility by overlap, are often not followed up. This leads to the deletion of PD turns at talk and therefore reduced participation in conversations. The implications of these phenomena for both client well-being and clinical interventions are discussed.

A new nonhydrolyzable affinity label Rp‐cGMPS‐BDB targets the cGMP binding site of human platelet PDE3A

Inhibitors of PDE3A, milrinone and cilostazol, interact with amino acids involved in cGMP binding. cGMP inhibits PDE3A. However the residues involved in cGMP binding in PDE3A are not completely categorized. We synthesized a nonhydrolyzable reactive cGMP analog, Rp-guanosine-3′,5′-cyclic-S-(4-bromo-2,3-dioxobutyl)monophosphorothioate, Rp-cGMPS-BDB with the goal to probe the cGMP site. Rp-cGMPS-BDB irreversibly inactivates PDE3A in a time-dependent fashion with KI = 43.4 ± 7.2 μM and kmax = 0.007 ± 0.0006 min−1. To identify the target site of Rp-cGMPS-BDB, nonhydrolyzable substrate and inhibitor analogs, and products were added prior to the inactivation of PDE3A by Rp-cGMPS-BDB. NAD, which is neither a substrate nor an inhibitor of PDE3A, does not protect against its inactivation by Rp-cGMPS-BDB. The effectiveness of protectants in decreasing the rate of inactivation by Rp-cGMPS-BDB is: Rp-cGMPS (Kd = 72 μM) > Sp-cGMPS (124), Sp-cAMPS (182) > GMP (1517), Rp-cAMPS (3762), AMP (4370 μM). Kinetic results from protection by Rp-cGMPS, Sp-cGMPS and Sp-cAMPS suggest that inactivation of PDE3A by Rp-cGMPS-BDB is a consequence of overlap between cAMP and cGMP binding sites but favors the cGMP site. The docking model of PDE3A-Rp-cGMPS-BDB shows that Rp-cGMPS-BDB is within the active site of PDE3A. Rp-cGMPS-BDB has proven to be an effective active site-directed affinity label for PDE3A with potential for other cGMP PDEs. Supported by PA/DE AHA grant 026439U, NIH grant HL-64943 and NSF grant MCB97-28202.

The perceptual consequences of overlap in /s/ and /∫/ productions within a talker

A primary issue in speech perception is the apparent lack of invariance between the acoustic information in a signal and the listeners perception. Different intended phonemes may be produced with identical acoustic values. Previously, we examined fricative centroids and frication peaks for over 100 utterances beginning with /s/ and /∫/ from each of 20 different speakers, and found substantial overlap across talkers. In the present study, we examine the effect of this overlap on perception. Listeners in a phoneme identification task heard natural productions of /s/ and /∫/ syllables from speakers with either little or great overlap between categories. Although labeling accuracy was near ceiling, effects were found in listeners’ reaction times. Listeners needed more time to interpret the speech of talkers who had substantial overlap in their fricative centroids, even when these talkers showed no overlap in their frication peaks. Listeners also had slower reaction times for talkers with overlap in their frication peaks, but not their centroids. This suggests that category overlap has measureable consequences to perception, and that peaks and centroids are sensitive to different aspects of the speech signal, both of which are perceptually impotant to listeners. [Work supported by NIDCD Grant R01-DC00219 to SUNY at Buffalo.]

Converging sources of evidence for dissecting articulatory movements into core gestures

Explaining and modeling the process of coarticulation is one of the central tasks of speech research. At the same time, the literature on the temporal extent of anticipatory coarticulation has been characterized by conflicting findings. In this paper, we bring together data from a number of different articulatory studies to argue that many of these inconsistencies can be resolved by careful comparison between minimally contrastive contexts. In particular, we examine reports of “one-” and “two-stage” coarticulatory patterns, and suggest that the occurrence of these patterns can be accounted for by factoring in the effects of neighboring segments and suprasegmental variables such as speaking rate. Our conclusions support the coproduction view of coarticulation as the consequence of overlap between spatio-temporally stable, context-independent gestures.

Derivative infrared spectroscopy of cotton cellulose

AbstractA new technique of derivative infrared spectroscopy for the study of polymer structure with special reference to cotton cellulose is described. Absorption spectra of cotton cellulose are compared with second deravative spectra. In case of absorption spectra, while determining the wavelength and intensity of a given absorption, in many cases, difficulties arise due to the presence of an interfering band which, as a consequence of overlap, prevents the determination of the above properties. Derivative spectroscopy provides valuable information on structural properties of cellulose. It yields spectra gradient, which facilitates the separation of overlapping absorption bands to resolve and detect absorptions; neither were unresolvable as a consequence either of multiple bands overlap or of low intensity. Hence, the measured wavelength in the second derivative spectra are more precise than the absorption spectra. For fine structural studies of cellulose, derivative spectra may provide more useful information as the absorption bands are more clearly defined.