27,079 research outputs found

    Articulatory insights into language variation and change: preliminary findings from an ultrasound study of derhoticization in Scottish English

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    <p>Scottish English is often cited as a rhotic dialect of English. However, in the 70s and 80s, researchers noticed that postvocalic /r/ was in attrition in Glasgow (Macafee, 1983) and Edinburgh (Romaine, 1978; Johnston and Speitel 1983). Recent research (Stuart-Smith, 2003) confirms that postvocalic /r/ as a canonical phonetically rhotic consonant is being lost in working-class Glaswegian speech. However, auditory and acoustic analysis revealed that the situation was more complicated than simple /r/ vs. zero variation. The derhoticized quality of /r/ seemed to vary socially; in particular male working class speakers often produced intermediate sounds that were difficult to identify. It is clear that although auditory and acoustic analysis are useful, they can only hint at what is going on in the vocal tract. A direct articulatory study is thus motivated.</p> <p>Instrumental phonetic studies that examine the vocal tract during the production of sustained rhotic consonants and in laboratory-based studies of American English /r/ have identified a complex relationship between articulation and acoustics, including articulatory differences with minimal acoustic consequences (starting with Delattre and Freeman, 1968). In other words, different gestural configurations can be used to generate a canonically rhotic consonant. A pilot study (Scobbie and Stuart-Smith, 2006) using Ultrasound Tongue Imaging (UTI) with a Scottish vernacular speaker revealed something rather different: the occurrence of a strong articulatory retroflex tongue motion, which generated little or no rhotic acoustic consequences because it was timed to occur after phonation had ceased, before pause. This tongue motion was found in a speaker who was weakly rhotic. Thus we may have a situation in which acoustic differences with a sociolinguistic function have, in some prosodic contexts, imperceptible articulatory differences in tongue position, though timing will vary. The situation of language variation and change in Scotland means that an articulatory/acoustic study is likely to give very different results to similar studies of rhotic speakers in the USA (Mielke, Twist, and Archangeli, 2006), and be particularly relevant to understanding social variation.</p> <p>Ultrasound is non-invasive and portable and therefore has great potential as an instrumental method for studying aspects of socially stratified variation: articulatory data can be physically collected in every-day social settings. However the technique requires refinement for effective use in recording locations outside the laboratory (e.g. in school, at home), and the potential impact of using the equipment on speech is not known. Gick (2002) suggest methods for fieldwork, but we are not aware of any study which attempts to quantify the effects of the technique on vernacular speakers.</p> <p>Ultrasound is non-invasive and portable and therefore has great potential as an instrumental method for studying aspects of socially stratified variation: articulatory data can be physically collected in every-day social settings. However the technique requires refinement for effective use in recording locations outside the laboratory (e.g. in school, at home), and the potential impact of using the equipment on speech is not known. Gick (2002) suggest methods for fieldwork, but we are not aware of any study which attempts to quantify the effects of the technique on vernacular speakers.</p&gt

    A single case study of articulatory adaptation during acoustic mimicry

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    The distribution of fine-grained phonetic variation can be observed in the speech of members of welldefined social groups. It is evident that such variation must somehow be able to propagate through a speech community from speaker to hearer. However, technological barriers have meant that close and direct study of the articulatory links of this speaker-hearer chain has not, to date, been possible. We present the results of a singlecase study using an ultrasound-based method to investigate temporal and configurational lingual adaptation during mimicry. Our study focuses on allophonic variants of postvocalic /r/ found in speech from Central Scotland. Our results show that our informant was able to adjust tongue gesture timing towards that of the stimulus, but did not alter tongue configuration

    Detection of Gravitational Waves from the Coalescence of Population-III Remnants with Advanced LIGO

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    The comoving mass density of massive black hole (MBH) remnants from pre-galactic star formation could have been similar in magnitude to the mass-density of supermassive black holes (SMBHs) in the present-day universe. We show that the fraction of MBHs that coalesce during the assembly of SMBHs can be extracted from the rate of ring-down gravitational waves that are detectable by Advanced LIGO. Based on the SMBH formation history inferred from the evolution of the quasar luminosity function, we show that an observed event rate of 1 per year will constrain the SMBH mass fraction that was contributed by MBHs coalescence down to a level of ~10^-6 for 20 solar mass MBH remnants (or ~10^-4 for 260 solar mass remnants).Comment: 4 pages, 2 figures. Submitted to ApJ Letter

    The buckling of thin-walled circular cylinders under axial compression and bending

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    Bucking of thin-walled electroplated copper and Mylar circular cylinders under axial compression and bendin

    Analyzing liquids

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    Applications of junction theory

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    Surface pinning of fluctuating charge order: an "extraordinary" surface phase transition

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    We study the mean-field theory of charge-density wave (CDW) order in a layered system, including the effect of the long-range Coulomb interaction and of screening by uncondensed electrons. We particularly focus on the conditions necessary for an ``extraordinary'' transition, in which the surface orders at a higher temperature, and is more likely to be commensurate, than the bulk. We interpret recent experiments on NaCCOC as indicating the presence of commensurate CDW at the surface that is not present in the bulk. More generally, we show that poor screening of the Coulomb interaction tends to stabilize incommensurate order, possibly explaining why the CDW order in LSCO and NbSe2 remains incommensurate to T -> 0, despite the small magnitude of the incommensurability.Comment: 9 pages, no figures, 31 references; 1 new figure and minor editing of the tex

    Relaxation dynamics at different time scales in electrostatic complexes: Time-salt superposition

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    In this Letter we show that in the rheology of electrostatically assembled soft materials, salt concentration plays a similar role as temperature for polymer melts, and as strain rate for soft solids. We rescale linear and nonlinear rheological data of a set of model electrostatic complexes at different salt concentrations to access a range of time scales that is otherwise inaccessible. This provides new insights into the relaxation mechanisms of electrostatic complexes, which we rationalize in terms of a microscopic mechanism underlying salt-enhanced activated processe

    Photometric Variability in Earthshine Observations

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    The identification of an extrasolar planet as Earth-like will depend on the detection of atmospheric signatures or surface non-uniformities. In this paper we present spatially unresolved flux light curves of Earth for the purpose of studying a prototype extrasolar terrestrial planet. Our monitoring of the photometric variability of earthshine revealed changes of up to 23 % per hour in the brightness of Earth's scattered light at around 600 nm, due to the removal of specular reflection from the view of the Moon. This variability is accompanied by reddening of the spectrum, and results from a change in surface properties across the continental boundary between the Indian Ocean and Africa's east coast. Our results based on earthshine monitoring indicate that specular reflection should provide a useful tool in determining the presence of liquid water on extrasolar planets via photometric observations.Comment: To appear in Astrobiology 9(3). 17 pages, 3 figures, 1 tabl
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