bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Place of Articulation Distinction in Voiced Oral Stops: Evidence from Burst Spectra and Formant Transitions
Authors: Cassidy Stephen , Harrington Jonathan 
Published: November 2009

Abstract
This study concerns the extent to which place of articulation in the voiced obstruents /b d dz g/ can be separated from spectral parameters taken in the burst, formant transitions, and a combination of the two. Classifications were obtained by training on citation-form data produced by male speakers and testing on (i) citation-form data produced by female speakers and (ii) continuous speech data produced by the same male speakers. The results show that there is more information for the place distinction in the burst than in formant transitions; when the parameters are combined into a single model, classification scores are improved for the citation-form data, but not for the continuous speech data. The highest classification scores were in the vicinity of 90% correct for both types of data on the combined parameters. The results are seen as supporting a model of sufficient discriminability rather than one in which phonetic categories are characterised by invariant acoustic cues.
A Perceptual Comparison of the /i/–/e/ and /u/–/o/ Contrasts in English and in Spanish: Universal and Language-Specific Aspects
Authors: Bradlow Ann R. 
Published: November 2009

Abstract
Two experiments were run to investigate language-specific and universal acoustic-perceptual characteristics of the /i/–/e/ and /u/–/o/ contrasts in two languages that differ widely in the sizes of their vowel inventories, namely, English and Spanish. In order to investigate the relationship between production and perception of these two vowel pairs, the first experiment compared the acoustic and perceptual characteristics of the /i/–/e/ and /u/–/o/ contrasts within each of the two languages. In order to investigate the responses of listeners to non-native stimuli, the second experiment presented native listeners of English and Spanish with synthetic /i/–/e/ and /u/–/o/ stimuli that were modeled after natural vowels as spoken by speakers of the other language. The results indicated a close production-perception link, as well as a degree of flexibility of the perceptual vowel space in response to stimuli that are structured around non-native vowel category locations. These results suggest that listeners perceive vowel stimuli with reference to a specific phonemic vowel system, and, if necessary, will adjust their perceptual vowel system to match the stimuli. Additionally, a comparison of the absolute locations of the /i/–/e/ and /u/–/o/ perceptual boundaries across the two languages indicated the presence of universally preferred, inventory-independent boundary locations.
The Acquisition of a Complex Phonological Contrast: Voice Timing Patterns of English Final Stops by Native French Speakers
Authors: Laeufer Christiane 
Published: November 2009

Abstract
This study examines the acquisition of the phonetic implementation of English final stops by two groups of French speakers. Investigated are parameters which demand a high degree of accuracy in the timing of the sequential movements of the glottal and supraglottal articulators. Rate of acquisition is found to be high for absolute vowel durations and unaspirated final stop release bursts. It is lower for flapping of alveolar stops and relative vowel durations, and it is lowest for extra-short stop closures and short-lag realization of voiced stops. The results confirm those obtained for initial stops. The factors facilitating the acquisition of L2 segments with close counterparts in L1 are the degree of perceptual salience of the various subsegmental intervals and the existence in L1 of allophonic variants similar in realization to the L2 segment. Acquisition begins with the positive transfer of these variants to L2 and their distributional extension to new contexts. In the presence of facilitating factors, it is restricted to the first few years of L2 exposure. In their absence, it requires longer exposure and is limited. Acquisition also strongly depends on individual factors.
Age of Learning Affects Rate-Dependent Processing of Stops in a Second Language
Authors: Flege James Emil , Schmidt Anna Marie , Wharton Glenn 
Published: November 2009

Abstract
The aim of this study was to assess the effect of speaking rate changes on the perception of English stop consonants by four groups of subjects: English and Spanish monolinguals, ‘early’ Spanish/English bilinguals who learned English in childhood, and ‘late’ bilinguals who learned English in adulthood. Subjects identified, and then later rated for goodness as exemplars of the English /p/ category, the members of two voice onset time (VOT) continua. The English monolinguals identified a well-defined range of VOT stimuli as English /p/, and stimuli with longer VOT values as ‘exaggerated’ instances of English /p/. Their goodness ratings increased as VOT increased, then showed a systematic decrease as VOT began to exceed values typical for English /p/. The English monolinguals’ goodness ratings also varied systematically as a function of speaking rate, which was simulated in the two continua by varying syllable duration. The Spanish monolinguals, on the other hand, failed to consistently identify any of the stimuli as English /p/. Although speaking rate influenced their goodness ratings, the Spanish monolinguals’ rate effects differed significantly from the English monolinguals’. The early bilinguals resembled the English monolinguals, and differed from the Spanish monolinguals to a greater extent than did the late Spanish/English bilinguals. This was taken as support for the hypothesis that early bilinguals are more likely than are late bilinguals to establish new phonetic categories for stop consonants in a second language.
Phonetic Interpretation of the Word Accent Contrast in Swedish: Evidence from Spontaneous Speech
Authors: Engstrand Olle 
Published: November 2009

Abstract
Fundamental frequency (F₀) correlates of the Swedish tonal word accents, ‘grave’ and ‘acute’, were studied in spontaneous speech produced by 3 male speakers of Central Standard Swedish. The grave accent was invariably marked by an F₀ fall on the primary stress syllable, while the corresponding F₀ contour in acute words seemed to be predictable from sentence-level intonation. The latter observation, which could not be tested on the basis of spontaneous speech data, was confirmed in a companion paper in which a controlled speech material was analysed. In combination, the two papers corroborate the view that an F₀ fall is a positive phonetic feature of the grave accent, while the acute accent constitutes the unmarked member of the contrast. They also illustrate the methodological advantage of using complementary spontaneous and controlled speech materials.
The Roles of Equatorial Trapped Waves and Internal Inertia–Gravity Waves in Driving the Quasi-Biennial Oscillation. Part I: Zonal Mean Wave Forcing
Authors: Kawatani Yoshio , Watanabe Shingo , Sato Kaoru , Dunkerton Timothy J. , Miyahara Saburo , Takahashi Masaaki 
Published: November 2009

Abstract
The roles of equatorial trapped waves (EQWs) and internal inertia–gravity waves in driving the quasi-biennial oscillation (QBO) are investigated using a high-resolution atmospheric general circulation model with T213L256 resolution (60-km horizontal and 300-m vertical resolution) integrated for three years. The model, which does not use a gravity wave drag parameterization, simulates a QBO. Although the simulated QBO has a shorter period than that of the real atmosphere, its amplitudes and structure in the lower stratosphere are fairly realistic. The zonal wavenumber/frequency spectra of simulated outgoing longwave radiation represent realistic signals of convectively coupled EQWs. Clear signals of EQWs are also seen in the stratospheric wind components. In the eastward wind shear of the QBO, eastward EQWs including Kelvin waves contribute up to ∼25%–50% to the driving of the QBO. The peaks of eastward wave forcing associated with EQWs and internal inertia–gravity waves occur at nearly the same time at the same altitude. On the other hand, westward EQWs contribute up to ∼10% to driving the QBO during the weak westward wind phase but make almost zero contribution during the relatively strong westward wind phase. Extratropical Rossby waves propagating into the equatorial region contribute ∼10%–25%, whereas internal inertia–gravity waves with zonal wavelength ≲1000 km are the main contributors to the westward wind shear phase of the simulated QBO.
The Roles of Equatorial Trapped Waves and Internal Inertia–Gravity Waves in Driving the Quasi-Biennial Oscillation. Part II: Three-Dimensional Distribution of Wave Forcing
Authors: Kawatani Yoshio , Watanabe Shingo , Sato Kaoru , Dunkerton Timothy J. , Miyahara Saburo , Takahashi Masaaki 
Published: November 2009

Abstract
Three-dimensional wave forcing of simulated quasi-biennial oscillation (QBO) is investigated using a high-resolution atmospheric general circulation model with T213L256 resolution (60-km horizontal and 300-m vertical resolution). In both the eastward and westward wind shear phases of the QBO, nearly all Eliassen–Palm flux (EP flux) divergence due to internal inertia–gravity waves (defined as fluctuations with zonal wavenumber ≥12) results from the divergence of the vertical component of the flux. On the other hand, EP flux divergence due to equatorial trapped waves (EQWs) results from both the meridional and vertical components of the flux in regions of strong vertical wind shear. Longitudinal dependence of wave forcing is also investigated by three-dimensional wave activity flux applicable to gravity waves. Near the top of the Walker circulation, strong eastward (westward) wave forcing occurs in the Eastern (Western) Hemisphere due to internal inertia–gravity waves with small horizontal phase speed. In the eastward wind shear zone associated with the QBO, the eastward wave forcing due to internal inertia–gravity waves in the Eastern Hemisphere is much larger than that in the Western Hemisphere, whereas in the westward wind shear zone, westward wave forcing does not vary much in the zonal direction. Zonal variation of wave forcing in the stratosphere results from (i) zonal variation of wave sources, (ii) the vertically sheared zonal winds associated with the Walker circulation, and (iii) the phase of the QBO.
Temporal Relations of Column Water Vapor and Tropical Precipitation
Authors: Holloway Christopher E. , Neelin J. David 
Published: November 2009

Abstract
Empirical studies using satellite data and radiosondes have shown that precipitation increases with column water vapor (CWV) in the tropics, and that this increase is much steeper above some critical CWV value. Here, eight years of 1-min-resolution microwave radiometer and optical gauge data at Nauru Island are analyzed to better understand the relationships among CWV, column liquid water (CLW), and precipitation at small time scales. CWV is found to have large autocorrelation times compared with CLW and precipitation. Before precipitation events, CWV increases on both a synoptic-scale time period and a subsequent shorter time period consistent with mesoscale convective activity; the latter period is associated with the highest CWV levels. Probabilities of precipitation increase greatly with CWV. Given initial high CWV, this increased probability of precipitation persists at least 10–12 h. Even in periods of high CWV, however, probabilities of initial precipitation in a 5-min period remain low enough that there tends to be a lag before the start of the next precipitation event. This is consistent with precipitation occurring stochastically within environments containing high CWV, with the latter being established by a combination of synoptic-scale and mesoscale forcing.
A General Theorem on Angular-Momentum Changes due to Potential Vorticity Mixing and on Potential-Energy Changes due to Buoyancy Mixing
Authors: Wood Richard B. , McIntyre Michael E. 
Published: November 2009

Abstract
An initial zonally symmetric quasigeostrophic potential vorticity (PV) distribution qi(y) is subjected to complete or partial mixing within some finite zone |y| &lt; L, where y is latitude. The change in M, the total absolute angular momentum, between the initial and any later time is considered. For standard quasigeostrophic shallow-water beta-channel dynamics it is proved that, for any qi(y) such that dqi/dy &gt; 0 throughout |y| &lt; L, the change in M is always negative. This theorem holds even when “mixing” is understood in the most general possible sense. Arbitrary stirring or advective rearrangement is included, combined to an arbitrary extent with spatially inhomogeneous diffusion. The theorem holds whether or not the PV distribution is zonally symmetric at the later time. The same theorem governs Boussinesq potential-energy changes due to buoyancy mixing in the vertical. For the standard quasigeostrophic beta-channel dynamics to be valid the Rossby deformation length LD ≫ εL where ε is the Rossby number; when LD = ∞ the theorem applies not only to the beta channel but also to a single barotropic layer on the full sphere, as considered in the recent work of Dunkerton and Scott on “PV staircases.” It follows that the M-conserving PV reconfigurations studied by those authors must involve processes describable as PV unmixing, or antidiffusion, in the sense of time-reversed diffusion. Ordinary jet self-sharpening and jet-core acceleration do not, by contrast, require unmixing, as is shown here by detailed analysis. Mixing in the jet flanks suffices. The theorem extends to multiple layers and continuous stratification. A least upper bound and greatest lower bound for the change in M is obtained for cases in which qi is neither monotonic nor zonally symmetric. A corollary is a new nonlinear stability theorem for shear flows.
A Bayesian Algorithm for Reconstructing Climate Anomalies in Space and Time. Part I: Development and Applications to Paleoclimate Reconstruction Problems
Authors: Tingley Martin P. , Huybers Peter 
Published: November 2009

AbstractReconstructing the spatial pattern of a climate field through time from a dataset of overlapping instrumental and climate proxy time series is a nontrivial statistical problem. The need to transform the proxy observations into estimates of the climate field, and the fact that the observed time series are not uniformly distributed in space, further complicate the analysis. Current leading approaches to this problem are based on estimating the full covariance matrix between the proxy time series and instrumental time series over a “calibration” interval and then using this covariance matrix in the context of a linear regression to predict the missing instrumental values from the proxy observations for years prior to instrumental coverage.A fundamentally different approach to this problem is formulated by specifying parametric forms for the spatial covariance and temporal evolution of the climate field, as well as “observation equations” describing the relationship between the data types and the corresponding true values of the climate field. A hierarchical Bayesian model is used to assimilate both proxy and instrumental datasets and to estimate the probability distribution of all model parameters and the climate field through time on a regular spatial grid. The output from this approach includes an estimate of the full covariance structure of the climate field and model parameters as well as diagnostics that estimate the utility of the different proxy time series.This methodology is demonstrated using an instrumental surface temperature dataset after corrupting a number of the time series to mimic proxy observations. The results are compared to those achieved using the regularized expectation–maximization algorithm, and in these experiments the Bayesian algorithm produces reconstructions with greater skill. The assumptions underlying these two methodologies and the results of applying each to simple surrogate datasets are explored in greater detail in Part II.
Forcing Processes of the Summertime Circumglobal Teleconnection Pattern in a Dry AGCM
Authors: Yasui Soichiro , Watanabe Masahiro 
Published: November 2009

Abstract
To better understand the predictability of the wavelike circumglobal teleconnection (CGT) pattern prevailing during boreal summer, two sets of experiments are performed using a nonlinear dry atmospheric model. Each experiment consists of a 10-member ensemble of 26-yr integrations driven by the diabatic heating derived from reanalysis data: one with the monthly climatological mean heating (CLIM) and the other with the monthly heating for 1979–2004 (HIST). Both do well in reproducing the observed summer mean state, as well as the low-frequency variance distribution. The CGT pattern identified in the monthly meridional wind anomalies at 200 hPa shows zonally oriented wave packets over Eurasia. The simulated CGT has a nearly identical phase structure with the observations and indicates little difference between the CLIM and HIST results. While this indicates that the origin of CGT lies in the internal dry dynamics, the ensemble mean of the CGT in HIST is partly controlled by the slow variation in the heating field, as indicated by the high potential predictability of the simulated CGT pattern. Diagnoses using the linearized model demonstrate that the heating anomaly most responsible for the CGT-like steady response is located over the eastern Mediterranean region, where the heating may be coupled with the CGT pattern. In addition to the heating near the CGT, remote heating and cooling anomalies over North America and equatorial Africa are found to be effective at exciting stationary Rossby waves trapped on the Atlantic and Asian jets. It is thus suggested that the mechanisms generating the heating anomalies over these regions are the key to the predictability of the CGT pattern.
Comparison of Rainfall Profiles in the West African Monsoon as Depicted by TRMM PR and the LMDZ Climate Model
Authors: Diatta Samo , Hourdin Frédéric , Gaye Amadou Thierno , Viltard Nicolas 
Published: November 2009

Abstract
Vertical rainfall profiles obtained with TRMM-PR 2A25 standard products are compared with rain profiles deduced from the Laboratoire de Météorologie Dynamique second generation global climate model (LMDZ, the Z stands for zoom capability) with two parameterization schemes: Emanuel’s and Tiedke’s. This paper focuses on the low layers of the atmosphere over West Africa during the monsoon [June–September (JJAS)]. The precipitation decrease above 4 km is systematically not represented in rainfall profiles generated by Emanuel’s parameterization scheme. However, Emanuel’s scheme shows a decrease similar to the observation from 4 km down to the surface, especially in the Sahel (proper depth of the layer dominated by reevaporation). As for Tiedtke’s scheme, it best describes the downward increase in the upper levels of the atmosphere, whereas the downward decrease in the lower levels begins too low when compared to the observations.
Tiedtke’s parameterization shows an overestimation of liquid water production over the ocean and over the Guinean region and a slightly too strong reevaporation in the Sahara and Sahel. The zonal distribution of vertical rain profiles is then biased with this model scheme compared to the 2A25-PR product. On the other hand, although Emanuel’s scheme detects too much reevaporation over the Sahara and underestimates liquid water production over the ocean compared to PR observation, it shows a good meridional distribution of these parameters. This is especially true in the Sahel where Emanuel’s scheme gives the best representation of reevaporation.
Observations of the Relationship between 700-mb Temperatures and Severe Weather Reports across the Contiguous United States
Authors: Bunkers Matthew J. , Wetenkamp John R. , Schild Jeffrey J. , Fischer Anthony 
Published: November 2009

Abstract
The relationship between 700-mb temperatures and convective severe storm reports is examined using data from 1993 to 2006 for the contiguous United States. Severe storm reports are used as a rough “proxy” for the occurrence of deep moist convection, and spatial and temporal distributions of 700-mb temperatures associated with these reports are analyzed. Secondarily, the distributions are assessed by individual severe storm report type, and convective inhibition also is evaluated. The motivation for this study is derived from the occasionally used 10°–12°C at 700 mb rule of thumb for estimating the extent and strength of the capping inversion. Whereas there is a semblance of merit for using this rule at times, its utility is shown to be strongly dependent on 1) geographic location, particularly with respect to surface elevation and the frequency of elevated mixed layers, and 2) the time of year. Calculation of convective inhibition, careful examination of the sounding, and assessment of lifting mechanisms likely are more valuable than 700-mb temperatures when forecasting the potential for deep moist convection and severe storms.
Barriers to Insulin Injection Therapy
Authors: Rubin Richard R. , Peyrot Mark , Kruger Davida F. , Travis Luther B. 
Published: November 2009

Objective To compare patients’ perceptions of injection-related problems with clinicians’ estimates of those problems. Methods Data were obtained through 2 Internet surveys, one of US adults self-identified as taking insulin to treat diabe- tes and the second of health care professionals who treat people with diabetes who inject insulin, including pri- mary care physicians, endocrinologists, and diabetes educators. Results A substantial majority of patients would like to reduce the number of injections they take each day; almost half said that they would be more likely to take their insulin injections regularly if a product were available to ease the pain. A much smaller proportion of patients reported that (1) injections were a serious burden, (2) they were dissatisfied with the way they took insulin, (3) injections had a substantial negative impact on qual- ity of life, (4) they skipped injections they should take, or (5) injection-related problems affected the number of injections they were willing to take. Half of the patients said they mentioned injection-related problems to their provider; a similar number reported that their providers had not given them a solution to problems with injection- related pain and bruising. Although awareness of prod- ucts to ease injection pain was high among providers (especially diabetes educators), this information was not effectively transmitted to patients. Conclusions Patients should be encouraged to discuss their injection- related concerns, and providers should regularly ask about injection-related problems. Providers should offer patients information about tools to reduce injection- related worries, preferably by having them available to show and demonstrate