27,079 research outputs found
Articulatory insights into language variation and change: preliminary findings from an ultrasound study of derhoticization in Scottish English
<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>
A single case study of articulatory adaptation during acoustic mimicry
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
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
Bucking of thin-walled electroplated copper and Mylar circular cylinders under axial compression and bendin
Surface pinning of fluctuating charge order: an "extraordinary" surface phase transition
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
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
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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