Temporal articulatory stability, phonological variation, and lexical contrast preservation in diaspora Tibetan

This dissertation examines how lexical tone can be represented with articulatory gestures, and the ways a gestural perspective can inform synchronic and diachronic analysis of the phonology and phonetics of a language. Tibetan is chosen an example of a language with interacting laryngeal and tonal phonology, a history of tonogenesis and dialect diversification, and recent contact-induced realignment of the tonal and consonantal systems. Despite variation in voice onset time (VOT) and presence/absence of the lexical tone contrast, speakers retain a consistent relative timing of consonant and vowel gestures. Recent research has attempted to integrate tone into the framework of Articulatory Phonology through the addition of tone gestures. Unlike other theories of phonetics-phonology, Articulatory Phonology uniquely incorporates relative timing as a key parameter. This allows the system to represent contrasts instantiated not just in the presence or absence of gestures, but also in how gestures are timed with each other. Building on the different predictions of various timing relations, along with the historical developments in the language, hypotheses are generated and tested with acoustic and articulatory experiments. Following an overview of relevant theory, the second chapter surveys past literature on the history of sound change and present phonological diversity of Tibetic dialects. Whereas Old Tibetan lacked lexical tone, contrasted voiced and voiceless obstruents, and exhibited complex clusters, a series of overlapping sound changes have led to some modern varieties that are tone, lack clusters, and vary in the expression of voicing and aspiration. Furthermore, speakers in the Tibetan diaspora use a variety that has grown out of the contact between diverse Tibetic dialects. The state of the language and the dynamics of diaspora have created a situation ripe for sound change, including the recombination of elements from different dialects and, potentially, the loss of tone contrasts. The nature of the diaspora Tibetan is investigated through an acoustic corpus study. Recordings made in Kathmandu, Nepal, are being transcribed and forced-aligned into a useful audio corpus. Speakers in the corpus come from diverse backgrounds across and outside traditional Tibetan-speaking regions, but the analysis presented here focuses on speakers who grew up in diaspora, with a mixed input of Standard Tibetan (spyi skad) and other Tibetan varieties. Especially notable among these speakers is the high variability of voice onset time (VOT) and its interaction with tone. An analysis of this data in terms of the relative timing of oral, laryngeal, and tone gestures leads to the generation of hypotheses for testing using articulatory data. The articulatory study is conducted using electromagnetic articulography (EMA), and six Tibetan-speaking participants. The key finding is that the relative timing of consonant and vowel gestures is consistent across phonological categories and across speakers who do and do not contrast tone. This result leads to the conclusion that the relative timing of speech gestures is conserved and acquired independently. Speakers acquire and generalize a limited inventory of timing patterns, and can use timing patterns even when the conditioning environment for the development of those patterns, namely tone, has been lost

Phonological Koinéization in Kathmandu Tibetan

This paper tests the new-dialect formation model of Peter Trudgill (1986 et seq) by examining several phonological features of Tibetan as spoken in the diaspora community of Kathmandu, Nepal. Established by an influx of migrants from many dialect regions beginning in 1959, this presents a unique opportunity to study koinéization, new dialect formation, in progress. Trudgill's model predicts that a new dialect should largely emerge in the second generation born in the new region, exhibiting both simplification, the failure of marked variants to transmit across generations, and focusing, the selection of particular variants as a new norm for the community's new variety.Data from seventy-three sociolinguistic interviews was coded for phonological and lexical variables known to differ across Tibetan-speaking regions, and NeighborNets were constructed in SplitsTree. Results indicate that regionally marked variables were not transmitted into the first or second generation of Diaspora-raised speakers, but Diaspora speakers exhibited a high degree of variation comparable to that of speakers from the numerically- and socially-dominant U-Tsang region. That younger speakers have not yet converged on a single new variety suggests a role for additional factors to affect the rate of koinéization

Gender representation in linguistic example sentences

Prior studies have shown that example sentences in syntax textbooks systematically under-represent women and perpetuate gender stereotypes (Macaulay & Brice 1994, 1997; Pabst et al. 2018). We examine the articles published over the past 20 years in Language, Linguistic Inquiry, and Natural Language & Linguistic Theory, and find striking similarities to this prior work. Among our findings, we show a stark imbalance of male (N=10807) to female (N=5019) arguments, and that male-gendered arguments are more likely to be subjects, and female arguments non-subjects. We show that female-gendered arguments are less likely to be referred to using pronouns and are more likely to be referred to using a kinship term, whereas male-gendered arguments are more likely to have occupations and to perpetrate violence. We show that this pattern has remained stable, with very little change, over the course of the twenty years that we examine, leading up to the present day. We conclude with a brief discussion of possible remedies and suggestions for improvement

The Resistance of Cortical Bone Tissue to Failure under Cyclic Loading is Reduced with Alendronate

Bisphosphonates are the most prescribed preventative treatment for osteoporosis. However, their long-term use has recently been associated with atypical fractures of cortical bone in patients who present with low-energy induced breaks of unclear pathophysiology. The effects of bisphosphonates on the mechanical properties of cortical bone have been exclusively studied under simple, monotonic, quasi-static loading. This study examined the cyclic fatigue properties of bisphosphonate-treated cortical bone at a level in which tissue damage initiates and is accumulated prior to frank fracture in low-energy situations. Physiologically relevant, dynamic, 4-point bending applied to beams (1.5 mm × 0.5 mm × 10 mm) machined from dog rib (n=12/group) demonstrated mechanical failure and micro-architectural features that were dependent on drug dose (3 groups: 0, 0.2, 1.0 mg/kg/day; Alendronate [ALN] for 3 years) with cortical bone tissue elastic modulus (initial cycles of loading) reduced by 21% (p<0.001) and fatigue life (number of cycles to failure) reduced in a stress-life approach by greater than 3-fold with ALN1.0 (p<0.05). While not affecting the number of osteons, ALN treatment reduced other features associated with bone remodeling, such as the size of osteons (−14%, ALN1.0: 10.5±1.8, VEH: 12.2±1.6, ×103 µm2; p<0.01) and the density of osteocyte lacunae (−20%; ALN1.0: 11.4±3.3, VEH: 14.3±3.6, ×102 #/mm2; p<0.05). Furthermore, the osteocyte lacunar density was directly proportional to initial elastic modulus when the groups were pooled (R=0.54, p<0.01). These findings suggest that the structural components normally contributing to healthy cortical bone tissue are altered by high-dose ALN treatment and contribute to reduced mechanical properties under cyclic loading conditions

Artificial intelligence based deconvolving on megavoltage photon beam profiles for radiotherapy applications

Objective. The aim of this work is an AI based approach to reduce the volume effect of ionization chambers used to measure high energy photon beams in radiotherapy. In particular for profile measurements, the air-filled volume leads to an inaccurate measurement of the penumbra. Approach. The AI-based approach presented in this study was trained with synthetic data intended to cover a wide range of realistic linear accelerator data. The synthetic data was created by randomly generating profiles and convolving them with the lateral response function of a Semiflex 3D ionization chamber. The neuronal network was implemented using the open source tensorflow.keras machine learning framework and a U-Net architecture. The approach was validated on three accelerator types (Varian TrueBeam, Elekta VersaHD, Siemens Artiste) at FF and FFF energies between 6 MV and 18 MV at three measurement depths. For each validation, a Semiflex 3D measurement was compared against a microDiamond measurement, and the AI processed Semiflex 3D measurement was compared against the microDiamond measurement. Main results. The AI approach was validated with dataset containing 306 profiles measured with Semiflex 3D ionization chamber and microDiamond. In 90% of the cases, the AI processed Semiflex 3D dataset agrees with the microDiamond dataset within 0.5 mm/2% gamma criterion. 77% of the AI processed Semiflex 3D measurements show a penumbra difference to the microDiamond of less than 0.5 mm, 99% of less than 1 mm. Significance. This AI approach is the first in the field of dosimetry which uses synthetic training data. Thus, the approach is able to cover a wide range of accelerators and the whole specified field size range of the ionization chamber. The application of the AI approach offers an quality improvement and time saving for measurements in the water phantom, in particular for large field size

Dental Fluoride Varnish Application During Medical Visits Among Children Who Are Privately Insured

This cross-sectional study examines fluoride varnish application rates during well-child medical visits and identify characteristics associated with fluoride varnish receipt