Automatic recognition of schwa variants in spontaneous Hungarian speech

This paper analyzes the nature of the process involved in optional vowel reduction in Hungarian, and the acoustic structure of schwa variants in spontaneous speech. The study focuses on the acoustic patterns of both the basic realizations of Hungarian vowels and their realizations as neutral vowels (schwas), as well as on the design, implementation, and evaluation of a set of algorithms for the recognition of both types of realizations from the speech waveform. The authors address the question whether schwas form a unified group of vowels or they show some dependence on the originally intended articulation of the vowel they stand for. The acoustic study uses a database consisting of over 4,000 utterances extracted from continuous speech, and recorded from 19 speakers. The authors propose methods for the recognition of neutral vowels depending on the various vowels they replace in spontaneous speech. Mel-Frequency Cepstral Coefficients are calculated and used for the training of Hidden Markov Models. The recognition system was trained on 2,500 utterances and then tested on 1,500 utterances. The results show that a neutral vowel can be detected in 72% of all occurrences. Stressed and unstressed syllables can be distinguished in 92% of all cases. Neutralized vowels do not form a unified group of phoneme realizations. The pronunciation of schwa heavily depends on the original articulation configuration of the intended vowel

DNA Methylation and Gene Expression Changes in Monozygotic Twins Discordant for Psoriasis: Identification of Epigenetically Dysregulated Genes

Monozygotic (MZ) twins do not show complete concordance for many complex diseases; for example, discordance rates for autoimmune diseases are 20%–80%. MZ discordance indicates a role for epigenetic or environmental factors in disease. We used MZ twins discordant for psoriasis to search for genome-wide differences in DNA methylation and gene expression in CD4+ and CD8+ cells using Illumina's HumanMethylation27 and HT-12 expression assays, respectively. Analysis of these data revealed no differentially methylated or expressed genes between co-twins when analyzed separately, although we observed a substantial amount of small differences. However, combined analysis of DNA methylation and gene expression identified genes where differences in DNA methylation between unaffected and affected twins were correlated with differences in gene expression. Several of the top-ranked genes according to significance of the correlation in CD4+ cells are known to be associated with psoriasis. Further, gene ontology (GO) analysis revealed enrichment of biological processes associated with the immune response and clustering of genes in a biological pathway comprising cytokines and chemokines. These data suggest that DNA methylation is involved in an epigenetic dysregulation of biological pathways involved in the pathogenesis of psoriasis. This is the first study based on data from MZ twins discordant for psoriasis to detect epigenetic alterations that potentially contribute to development of the disease

Vowel reduction in word-final position by early and late Spanish-English bilinguals

Vowel reduction is a prominent feature of American English, as well as other stress-timed languages. As a phonological process, vowel reduction neutralizes multiple vowel quality contrasts in unstressed syllables. For bilinguals whose native language is not characterized by large spectral and durational differences between tonic and atonic vowels, systematically reducing unstressed vowels to the central vowel space can be problematic. Failure to maintain this pattern of stressed-unstressed syllables in American English is one key element that contributes to a ?foreign accent? in second language speakers. Reduced vowels, or ?schwas,? have also been identified as particularly vulnerable to the co-articulatory effects of adjacent consonants. The current study examined the effects of adjacent sounds on the spectral and temporal qualities of schwa in word-final position. Three groups of English-speaking adults were tested: Miami-based monolingual English speakers, early Spanish-English bilinguals, and late Spanish-English bilinguals. Subjects performed a reading task to examine their schwa productions in fluent speech when schwas were preceded by consonants from various points of articulation. Results indicated that monolingual English and late Spanish-English bilingual groups produced targeted vowel qualities for schwa, whereas early Spanish-English bilinguals lacked homogeneity in their vowel productions. This extends prior claims that schwa is targetless for F2 position for native speakers to highly-proficient bilingual speakers. Though spectral qualities lacked homogeneity for early Spanish-English bilinguals, early bilinguals produced schwas with near native-like vowel duration. In contrast, late bilinguals produced schwas with significantly longer durations than English monolinguals or early Spanish-English bilinguals. Our results suggest that the temporal properties of a language are better integrated into second language phonologies than spectral qualities. Finally, we examined the role of nonstructural variables (e.g. linguistic history measures) in predicting native-like vowel duration. These factors included: Age of L2 learning, amount of L1 use, and self-reported bilingual dominance. Our results suggested that different sociolinguistic factors predicted native-like reduced vowel duration than predicted native-like vowel qualities across multiple phonetic environments

Historical review of die drool phenomenon in plastics extrusion

Die drool phenomenon is defined as unwanted spontaneous accumulation of extruded plastics on die exit face(s) of extrusion die during plastics extrusion process. Such accumulated material builds up on die exit face(s) and frequently or continually sticks onto the extruded product and by this way reduces the quality of the product. When the die drool appears, the extrusion process must be shut down and the die exit face(s) must be manually cleaned, which is time consuming as well as money consuming. Die drool has been observed from the beginning of plastics extrusion and the first published remark about it was made in 1946. For a long time it was considered as only an engineering problem and even if a wide range of suppressing ideas based on modification of extrusion dies, plastics materials, and processing conditions have already been patented, its source remained unclear. During the last few years, a number of experimental as well as theoretical research papers focusing on its fundamental nature have been published. Nowadays, die drool is considered as a fundamental rheological phenomenon. The force which drives the building up of extruded plastics on die exit face(s) is negative pressure (suction) occurring in the die exit edge(s) region where the free surface of the extruded plastics is created. Moreover, two different die drool types (external and internal) exist. The formation mechanisms of external/internal die drool are based on negative pressure occurring in the die exit region together with deformation of free extrudate surface/material separation wherever inside the extrusion equipment, respectively. From the processing point of view, the internal die drool is much more problematic than the external one, primarily due to a higher build up rate and compact shapes of the accumulated drool mass. Two theories of internal die drool formation mechanism based on wall slip theories (flow-induced molecular weight fractionation and stress-induced cohesive chain disentanglement) have been recently proposed and tested. In this historically ordered review, breakthrough works in the field of die drool research are presented, many ways to suppress it are shown, techniques for its quantitative evaluation and experimental methods for its analytical investigation are introduced, external and internal die drool types are explained, and theories of external as well as internal die drool formation mechanism are presented and discussed in depth, which can be especially helpful for plastics extrusion experts as well as for the rheological community. © 2014 Taylor and Francis Group, LLC