Search

Insulin clearance is an integral component of insulin metabolism. Yet, little is known about separate contribution of hepatic and extrahepatic insulin clearance in type 2 diabetes and in high-risk populations, such as women who experienced gestational diabetes mellitus (pGDM). A model-based method was recently proposed to assess both contributions from 3-hour insulin-modified intravenous glucose tolerance test (IM-IVGTT); the aim of this study was to assess the reliability of short (1 hour) IM-IVGTT in the application of such model-based method and to evaluate the role of the two contributions in determining insulin clearance in pGDM. A total of 115 pGDM women and 41 who remained healthy during pregnancy (CNT) were analyzed early postpartum and underwent a 3-hour IMIVGTT. Peripheral insulin clearance (CL P ), hepatic fractional extraction (FE L ) and extrahepatic distribution volume (V P ) were estimated by performing a best-fit procedure on insulin IMIVGTT data considering firstly the overall 3-hour duration and then limiting data to 1 hour. Results showed no significant difference in parameter values between the 3-hour and the 1-hour IM-IVGTT. Comparison between pGDM and CNT (1-hour) showed no significant difference in CL p (0.23 [0.29] vs. 0.27 [0.43] L·min -1 ; p=0.64), FE L (50.2 [15.1] vs. 50.9 [11.7] %; p=0.63) and V P (2.01 [2.99] vs. 2.70 [4.00] L; p=0.92). In conclusion, short IM-IVGTT provides a reliable assessment of hepatic and extrahepatic insulin clearance through such model-based method. Its application to the study of pGDM women showed no alteration in hepatic and extrahepatic contributions with respect to women who had a healthy pregnancy.Clinical Relevance- This study proves the reliability of short (1 hour) IM-IVGTT to assess hepatic and extrahepatic insulin clearance in women who experienced gestational diabetes.

The relationship between prosody and perceived affect involves multiple variables. This paper explores the interplay of three: voice quality, f 0 contour, and the hearer's language background. Perception tests were conducted with speakers of Irish English, Russian, Spanish, and Japanese using three types of synthetic stimuli: (1) stimuli varied in voice quality, (2) stimuli of uniform (modal) voice quality incorporating affect-related f 0 contours, and (3) stimuli combining specific non-modal voice qualities with the affect-related f 0 contours of (2). The participants rated the stimuli for the presence/strength of affective colouring on six bipolar scales, e.g., happy-sad . The results suggest that stimuli incorporating non-modal voice qualities, with or without f 0 variation, are generally more effective in affect cueing than stimuli varying only in f 0 . Along with similarities in the affective responses across these languages, many points of divergence were found, both in terms of the range and strength of affective responses overall and in terms of specific stimulus-to-affect associations. The f 0 contour may play a more important role, and tense voice a lesser role in affect signalling in Japanese and Spanish than in Irish English and Russian. The greatest cross-language differences emerged for the affects intimate, formal , stressed , and relaxed.

In emotional speech research, it has been suggested that loudness, along with other prosodic features, may be an important cue in communicating high activation affects. In earlier studies, we found different voice quality stimuli to be consistently associated with certain affective states. In these stimuli, as in typical human productions, the different voice qualities entailed differences in loudness. To examine the extent to which the loudness differences among these voice qualities might influence the affective coloring they impart, two experiments were conducted with the synthesized stimuli, in which loudness was systematically manipulated. Experiment 1 used stimuli with distinct voice quality features including intrinsic loudness variations and stimuli where voice quality (modal voice) was kept constant, but loudness was modified to match the non-modal qualities. If loudness is the principal determinant in affect cueing for different voice qualities, there should be little or no difference in the responses to the two sets of stimuli. In Experiment 2, the stimuli included distinct voice quality features but all had equal loudness to test the hypothesis that equalizing the perceived loudness of different voice quality stimuli will have relatively little impact on affective ratings. The results suggest that loudness variation on its own is relatively ineffective whereas variation in voice quality is essential to the expression of affect. In Experiment 1, stimuli incorporating distinct voice quality features consistently obtained higher ratings than the modal voice stimuli with varied loudness. In Experiment 2, non-modal voice quality stimuli proved potent in affect cueing even with loudness differences equalized. Although loudness per se does not seem to be the major determinant of perceived affect, it can contribute positively to affect cueing: when combined with a tense or modal voice quality, increased loudness can enhance signaling of high activation states.

The present study examines the extent to which increased nasal coupling affects estimates of glottal parameters derived from inverse filtering based on an all-pole assumption of the vocal tract. A series of steady-state tokens for five Swedish vowels were synthesized using the HLsyn quasi-articulatory synthesizer (Sensimetrics, Malden, MA). For each vowel, the parameter controlling the cross-sectional area of the nasal aperture, an, was systematically varied, while the other HLsyn parameters were kept constant. The resultant pressure signal for each utterance was subsequently inverse filtered, and estimates were made of five glottal source parameters (EE, RG, RA, RK, and OQ) derived from fitting the Liljencrants and Fant source model to the inverse filtered signal. The results show that when analyzing nasalized vowels using inverse filtering based on an all-pole assumption of the vocal tract, the RA parameter estimate--a main determinant of the source spectral slope--can be adversely affected by nasal coupling. The errors in our estimates were particularly high for the high vowels: this was true not only for RA, but for all the parameters measured. However, with the exception of the distortion in the RA estimate, the effects were relatively small, regardless of the degree of nasal coupling., (Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.)

The contextual effects of voiced/voiceless stops on the voice source of an adjacent vowel were examined for the first vowel in 'CVCV utterances in German, English, Swedish, French, and Italian. The principal analysis technique involved interactive inverse filtering and parameterisation of the glottal waveform in terms of a four-parameter voice source model (the LF-model). This analysis procedure was supplemented by measures from narrow-band spectral sections of the speech output and by oral airflow recordings which allow inferences about the relative timing of glottal and supraglottal gestures. Results indicated that the voiced/voiceless nature of the consonant does yield differences in the voice source of the vowel. The most striking effects were found in the context of voiceless consonants, and cross-language differences did emerge in terms of directionality and degree. Extensive anticipatory effects were found for Swedish and for some speakers of English. Preceding the voiceless stop the vowel becomes increasingly breathy-voiced, and it would appear that the glottal abduction gesture is anticipated very early in the course of the vowel. Italian exhibited a similar tendency, though to a considerably lesser degree. The German data, on the other hand, showed certain strong carryover effects: Following the voiceless aspirated stop there was extensive breathy voicing. French showed little contextual variation in either direction. Rather surprisingly, the observed effects were not directly correlated with, or predictable from, the phonetic categories involved (voiced, voiceless unaspirated, and voiceless postaspirated). These results yield insights into the control parameters which may be involved in regulating voicing oppositions in these languages. Whereas the anticipatory effects observed might be consistent with a "timing" model of glottal control, the carryover effects cannot be explained in terms of timing alone and suggest that differences in tension settings of the laryngeal musculature may also be implicated.