Instrumental swallowing assessment in adults in residential aged care homes : Practice patterns and opportunities

Objective To describe practice patterns in the use of instrumental swallowing assessment (ISA) for older adults in residential aged care homes (RACHs). Methods A retrospective audit of medical records of residents living in RACHs in Melbourne, Australia to extract data on speech-language pathologist (SLP) involvement, indications for ISA and ISA practice patterns. Results Medical files of 323 residents across four Melbourne facilities were reviewed. 36% (n = 115) of residents were referred to SLP for swallowing assessment. Referral to SLP was related to length of stay (U = 7393.00, p < 0.001), dementia status (χ2[1] = 7.06, p = 0.008), texture modification (χ2[1] = 93.34, p < 0.001) and an existing dysphagia diagnosis (χ2[1] = 112.89, p < 0.001). There were no referrals for ISA and no instances of ISA being used. Among 115 residents who were referred to SLP for swallowing assessment, there were 33 instances where ISA might be clinically relevant according to ISA indicators. Conclusions Instrumental swallowing assessment is not being used for the management of swallowing in RACHs in Australia despite a clinical need for ISA and a potential role for ISA to improve swallowing care quality. Lack of timely ISA may fail to meet the complex health-care needs of older adults living with dysphagia in RACHs, increasing their vulnerability to complications of dysphagia and its management

Quantifying ultrasonic mouse vocalizations using acoustic analysis in a supervised statistical machine learning framework

Examination of rodent vocalizations in experimental conditions can yield valuable insights into how disease manifests and progresses over time. It can also be used as an index of social interest, motivation, emotional development or motor function depending on the animal model under investigation. Most mouse communication is produced in ultrasonic frequencies beyond human hearing. These ultrasonic vocalizations (USV) are typically described and evaluated using expert defined classification of the spectrographic appearance or simplistic acoustic metrics resulting in nine call types. In this study, we aimed to replicate the standard expert-defined call types of communicative vocal behavior in mice by using acoustic analysis to characterize USVs and a principled supervised learning setup. We used four feature selection algorithms to select parsimonious subsets with maximum predictive accuracy, which are then presented into support vector machines (SVM) and random forests (RF). We assessed the resulting models using 10-fold cross-validation with 100 repetitions for statistical confidence and found that a parsimonious subset of 8 acoustic measures presented to RF led to 85% correct out-of-sample classification, replicating the experts' labels. Acoustic measures can be used by labs to describe USVs and compare data between groups, and provide insight into vocal-behavioral patterns of mice by automating the process on matching the experts' call types

Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward-Backward Motion

Performing molecular dynamics simulations for all-atom models, we characterize the conformational and structural relaxations of poly(ethylene oxide) and poly(propylene oxide) melts. The temperature dependence of these relaxation processes deviates from an Arrhenius law for both polymers. We demonstrate that mode-coupling theory captures some aspects of the glassy slowdown, but it does not enable a complete explanation of the dynamical behavior. When the temperature is decreased, spatially heterogeneous and cooperative translational dynamics are found to become more important for the structural relaxation. Moreover, the transitions between the conformational states cease to obey Poisson statistics. In particular, we show that, at sufficiently low temperatures, correlated forward-backward motion is an important aspect of the conformational relaxation, leading to strongly nonexponential distributions for the waiting times of the dihedrals in the various conformational statesComment: 13 pages, 13 figure

Logopenic and nonfluent variants of primary progressive aphasia are differentiated by acoustic measures of speech production

Differentiation of logopenic (lvPPA) and nonfluent/agrammatic (nfvPPA) variants of Primary Progressive Aphasia is important yet remains challenging since it hinges on expert based evaluation of speech and language production. In this study acoustic measures of speech in conjunction with voxel-based morphometry were used to determine the success of the measures as an adjunct to diagnosis and to explore the neural basis of apraxia of speech in nfvPPA. Forty-one patients (21 lvPPA, 20 nfvPPA) were recruited from a consecutive sample with suspected frontotemporal dementia. Patients were diagnosed using the current gold-standard of expert perceptual judgment, based on presence/absence of particular speech features during speaking tasks. Seventeen healthy age-matched adults served as controls. MRI scans were available for 11 control and 37 PPA cases; 23 of the PPA cases underwent amyloid ligand PET imaging. Measures, corresponding to perceptual features of apraxia of speech, were periods of silence during reading and relative vowel duration and intensity in polysyllable word repetition. Discriminant function analyses revealed that a measure of relative vowel duration differentiated nfvPPA cases from both control and lvPPA cases (r2 = 0.47) with 88% agreement with expert judgment of presence of apraxia of speech in nfvPPA cases. VBM analysis showed that relative vowel duration covaried with grey matter intensity in areas critical for speech motor planning and programming: precentral gyrus, supplementary motor area and inferior frontal gyrus bilaterally, only affected in the nfvPPA group. This bilateral involvement of frontal speech networks in nfvPPA potentially affects access to compensatory mechanisms involving right hemisphere homologues. Measures of silences during reading also discriminated the PPA and control groups, but did not increase predictive accuracy. Findings suggest that a measure of relative vowel duration from of a polysyllable word repetition task may be sufficient for detecting most cases of apraxia of speech and distinguishing between nfvPPA and lvPPA

Slow dynamics near glass transitions in thin polymer films

The $\alpha$-process (segmental motion) of thin polystyrene films supported on glass substrate has been investigated in a wider frequency range from 10$^{-3}$ Hz to 10$^4$ Hz using dielectric relaxation spectroscopy and thermal expansion spectroscopy. The relaxation rate of the $\alpha$-process increases with decreasing film thickness at a given temperature above the glass transition. This increase in the relaxation rate with decreasing film thickness is much more enhanced near the glass transition temperature. The glass transition temperature determined as the temperature at which the relaxation time of the $\alpha$-process becomes a macroscopic time scale shows a distinct molecular weight dependence. It is also found that the Vogel temperature has the thickness dependence, i.e., the Vogel temperature decreases with decreasing film thickness. The expansion coefficient of the free volume $\alpha_f$ is extracted from the temperature dependence of the relaxation time within the free volume theory. The fragility index $m$ is also evaluated as a function of thickness. Both $\alpha_f$ and $m$ are found to decrease with decreasing film thickness.Comment: 9 pages, 7 figures, and 2 table

Quantum-scissors device for optical state truncation: A proposal for practical realization

We propose a realizable experimental scheme to prepare superposition of the vacuum and one-photon states by truncating an input coherent state. The scheme is based on the quantum scissors device proposed by Pegg, Phillips, and Barnett [Phys. Rev. Lett. 81, 1604 (1998)] and uses photon-counting detectors, a single-photon source, and linear optical elements. Realistic features of the photon counting and single-photon generation are taken into account and possible error sources are discussed together with their effect on the fidelity and efficiency of the truncation process. Wigner function and phase distribution of the generated states are given and discussed for the evaluation of the proposed scheme.Comment: 11 pages, 12 figures, the final version to appear in Phys. Rev. A64, 0638xx (2001

Bounds on the tau and muon neutrino vector and axial vector charge radius

A Majorana neutrino is characterized by just one flavor diagonal electromagnetic form factor: the anapole moment, that in the static limit corresponds to the axial vector charge radius . Experimental information on this quantity is scarce, especially in the case of the tau neutrino. We present a comprehensive analysis of the available data on the single photon production process $e^+ e^- -> \nu \bar\nu \gamma$ off Z-resonance, and we discuss the constraints that these measurements can set on for the tau neutrino. We also derive limits for the Dirac case, when the presence of a vector charge radius is allowed. Finally, we comment on additional experimental data on $\nu_\mu$ scattering from the NuTeV, E734, CCFR and CHARM-II collaborations, and estimate the limits implied for and for the muon neutrino.Comment: 20 pages, 2 eps figures. CCFR data included in the analysis. Conclusion unchange

Reconstruction of quantum states of spin systems via the Jaynes principle of maximum entropy

We apply the Jaynes principle of maximum entropy for the partial reconstruction of correlated spin states. We determine the minimum set of observables which are necessary for the complete reconstruction of the most correlated states of systems composed of spins-1/2 (e.g., the Bell and the Greenberger-Horne-Zeilinger states). We investigate to what extent an incomplete measurement can reveal nonclassical features of correlated spin states.Comment: 14 pages + 3 tables, LaTeX with revtex, to appear in J. Mod. Op

Slow dynamics and aging in a non-randomly frustrated spin system

A simple, non-disordered spin model has been studied in an effort to understand the origin of the precipitous slowing down of dynamics observed in supercooled liquids approaching the glass transition. A combination of Monte Carlo simulations and exact calculations indicates that this model exhibits an entropy vanishing transition accompanied by a rapid divergence of time scales. Measurements of various correlation functions show that the system displays a hierarchy of time scales associated with different degrees of freedom. Extended structures, arising from the frustration in the system, are identified as the source of the slow dynamics. In the simulations, the system falls out of equilibrium at a temperature $T_{g}$ higher than the entropy-vanishing transition temperature and the dynamics below $T_{g}$ exhibits aging as distinct from coarsening. The cooling rate dependence of the energy is also consistent with the usual glass formation scenario.Comment: 41 pages, 16 figures. Bibliography file is correcte