Closing and opening phase variability in dysphonia

Four examples of the use of vocal fold contact phase measurement are discussed for unilateral paresis. In each case this aspect of voice quality is of greater importance than the physical measurement of loudness and pitch related parameters. For three of the cases electro-stimulation has been used as a main part of the treatment. Phonation in both connected speech and, for comparison, in sustained sound production has been used with electro-laryngograph / egg signals providing the basis for measurement. The main new descriptors that have been found to be useful relate to: vocal fold closure and closure duration regularities and distributions; but reference is also made to related measures of peak acoustic amplitude. The new measures described give, in some cases, quite striking results that are of auditory significance and potentially of clinical value

Accuracy and variability of acoustic measures of voicing onset

Five commonly used methods for determining the onset of voicing of syllable-initial stop consonants were compared. The speech and glottal activity of 16 native speakers of Cantonese with normal voice quality were investigated during the production of consonant vowel (CV) syllables in Cantonese. Syllables consisted of the initial consonants /ph/, /th/, /kh/, /p/, /t/, and /k/ followed by the vowel /a/. All syllables had a high level tone, and were all real words in Cantonese. Measurements of voicing onset were made based on the onset of periodicity in the acoustic waveform, and on spectrographic measures of the onset of a voicing bar (f0), the onset of the first formant (F1), second formant (F2), and third formant (F3). These measurements were then compared against the onset of glottal opening as determined by electroglottography. Both accuracy and variability of each measure were calculated. Results suggest that the presence of aspiration in a syllable decreased the accuracy and increased the variability of spectrogram-based measurements, but did not strongly affect measurements made from the acoustic waveform. Overall, the acoustic waveform provided the most accurate estimate of voicing onset; measurements made from the amplitude waveform were also the least variable of the five measures. These results can be explained as a consequence of differences in spectral tilt of the voicing source in breathy versus modal phonation. ©2003 Acoustical Society of America.published_or_final_versio

Vocal fold vibratory patterns in tense versus lax phonation contrasts

This study explores the vocal fold contact patterns of one type of phonation contrast--the tense vs lax phonation contrasts of three Yi (Loloish) languages. These contrasts are interesting because neither phonation category is very different from modal voice, and because both phonations are largely independent of the languages' tonal contrasts. Electroglottographic (EGG) recordings were made in the field, and traditional EGG measures were derived. These showed many small but significant differences between the phonations, with tense phonation having greater contact quotients and briefer but slower changes in contact. Functional data analysis was then applied to entire EGG pulse shapes. The resulting first principal component was found to be mostly strongly related to the phonation contrasts, and correlated with almost all the traditional EGG measures. Unlike the traditional measures, however, this component also seems to capture differences in abruptness of contact. Furthermore, previously collected perceptual responses from native speakers of one of the languages correlated better with this component than with any other EGG measure or any acoustic measure. The differences between these tense and lax phonations are not large, but apparently they are consistent enough, and perceptually robust enough, to support this linguistic contrast

A Ligand Peptide Motif Selected from a Cancer Patient Is a Receptor-Interacting Site within Human Interleukin-11

Interleukin-11 (IL-11) is a pleiotropic cytokine approved by the FDA against chemotherapy-induced thrombocytopenia. From a combinatorial selection in a cancer patient, we isolated an IL-11-like peptide mapping to domain I of the IL-11 (sequence CGRRAGGSC). Although this motif has ligand attributes, it is not within the previously characterized interacting sites. Here we design and validate in-tandem binding assays, site-directed mutagenesis and NMR spectroscopy to show (i) the peptide mimics a receptor-binding site within IL-11, (ii) the binding of CGRRAGGSC to the IL-11Rα is functionally relevant, (iii) Arg4 and Ser8 are the key residues mediating the interaction, and (iv) the IL-11-like motif induces cell proliferation through STAT3 activation. These structural and functional results uncover an as yet unrecognized receptor-binding site in human IL-11. Given that IL-11Rα has been proposed as a target in human cancer, our results provide clues for the rational design of targeted drugs

Die interperiodische Irregularität ist unabhängig von der "closed-phase-control"

Hintergrund: Die Elektroglottgraphie hat sich als glottographisches Verfahren zur Beurteilung der Stimmlippenschwingungsregularität bewährt. Mit anerkannten Verfahren kann der jeweilige periodendauerbezogene RAP berechnet werden. Es ist bisher allerdings nicht bekannt, ob intraperiodische Irregularitäten mit den interperiodischen Abweichungen eines Zielwertes übereinstimmen. Material und Methoden: In der vorliegenden Studie wurde querschnittlich bei über 100 Patienten mit einseitiger Rekurrensparese der Irregularitätsindex, bezogen auf die Periodendauer (Ifreq), mit dem Irregularitätsindex, bezogen auf den Geschlossenanteil (Icq), verglichen. Ergebnisse: Anhand von ausgewählten Beispielen kann gezeigt werden, dass trotz stabilem Ifreq z.T. deutlich differente Icq gemessen werden können. Diskussion: Die Spannungskontrolle der Stimmlippen ist eine der Voraussetzungen für geringe RAP - Werte. Die hier vorgestellten Ergebnisse lassen vermuten, dass auch hohe Icq - Werte bei regelrechten Ifreq Werten möglich sind. Die "closed-phase control" wird vermutlich ebenfalls von der Spannungskontrolle determiniert. Weitere Untersuchungen werden klären müssen, inwieweit hohe Icq - Werte zum auditiven Eindruck der Rauhigkeit beitragen

Influence of forest tree species composition on bryophytic diversity in mixed and pure pine (Pinus sylvestris L.) and oak (Quercus petraea (Matt.) Liebl.) stands

The effects of mixed stands on biodiversity are increasingly being studied since they are supposed to offer higher habitat heterogeneity. Nevertheless, for tree-associated diversity, including epiphytes and terricolous species near tree trunks, few studies exist, and still fewer compare mixed stands with each corresponding pure tree species stand. We evaluated and quantified the influence of forest composition on tree-associated bryophyte diversity (species richness, abundance, composition) in mixed and pure oak-pine stands in a French lowland forest. The main explanatory variables for bryophyte diversity at tree-level were the identity of the phorophyte tree species and the mixture type (pure versus mixed). At the plot level, the main explanatory variable was the stand type (pure oak, pure pine and mixed). We also explored the role of other variables including the chemistry of the bryophyte substrates (soil, bark) and water supply (stemflow, throughfall), as well as stand abundance variables (basal area, interfering plant cover). We analyzed data with Generalized Linear Models under Bayesian statistics, to take into account the spatial autocorrelation between plots and any under- or over-dispersion of our data. At the tree-level, bryophyte richness and abundance were higher on oak than on pine. Pine bryophyte richness was higher in mixed compared to pure stands, whereas for oak, mixed stands did not enhance bryophyte richness. At the plot level, mixed stands hosted bryophyte communities of similar richness to those in pure oak stands, whereas pure pine stands were clearly poorer. Our exploratory models suggested strong effects of water supply chemistry (stemflow and throughfall pH or conductivity) and basal area; the latter had a strong quadratic effect on epiphytic richness at the plot level. In terms of composition, three species were more likely to be found on pine phorophytes, seven species clearly occurred more frequently on oaks. Some species were more likely to be associated to pine in mixed than in pure stands, and one species was found more often under pines in pure stands. Therefore, bryophyte diversity at the landscape level should benefit from the simultaneous presence of the three stand composition types - pure oak, pure pine and mixed stands