38,919 research outputs found

    Video Evidence That London Infants Can Resettle Themselves Back to Sleep After Waking in the Night, as well as Sleep for Long Periods, by 3 Months of Age

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    Objective: Most infants become settled at night by 3 months of age, whereas infants not settled by 5 months are likely to have long-term sleep-waking problems. We assessed whether normal infant development in the first 3 months involves increasing sleep-period length or the ability to resettle autonomously after waking in the night. Methods: One hundred one infants were assessed at 5 weeks and 3 months of age using nighttime infrared video recordings and parental questionnaires. Results: The clearest development was in sleep length; 45% of infants slept continuously for 5 hours or more at night at 3 months compared with 10% at 5 weeks. In addition, around a quarter of infants woke and resettled themselves back to sleep in the night at each age. Autonomous resettling at 5 weeks predicted prolonged sleeping at 3 months suggesting it may be a developmental precursor. Infants reported by parents to sleep for a period of 5 hours or more included infants who resettled themselves and those with long sleeps. Three-month olds fed solely breast milk were as likely to self-resettle or have long sleep bouts as infants fed formula or mixed breast and formula milk. Conclusions: Infants are capable of resettling themselves back to sleep in the first 3 months of age; both autonomous resettling and prolonged sleeping are involved in “sleeping through the night” at an early age. Findings indicate the need for physiological studies of how arousal, waking, and resettling develop into sustained sleeping and of how environmental factors support these endogenous and behavioral processes

    Wavelet-based voice morphing

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    This paper presents a new multi-scale voice morphing algorithm. This algorithm enables a user to transform one person's speech pattern into another person's pattern with distinct characteristics, giving it a new identity, while preserving the original content. The voice morphing algorithm performs the morphing at different subbands by using the theory of wavelets and models the spectral conversion using the theory of Radial Basis Function Neural Networks. The results obtained on the TIMIT speech database demonstrate effective transformation of the speaker identity

    Voice morphing using the generative topographic mapping

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    In this paper we address the problem of Voice Morphing. We attempt to transform the spectral characteristics of a source speaker's speech signal so that the listener would believe that the speech was uttered by a target speaker. The voice morphing system transforms the spectral envelope as represented by a Linear Prediction model. The transformation is achieved by codebook mapping using the Generative Topographic Mapping, a non-linear, latent variable, parametrically constrained, Gaussian Mixture Model

    Covariance, Dynamics and Symmetries, and Hadron Form Factors

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    We summarise applications of Dyson-Schwinger equations to the theory and phenomenology of hadrons. Some exact results for pseudoscalar mesons are highlighted with details relating to the U_A(1) problem. We describe inferences from the gap equation relating to the radius of convergence for expansions of observables in the current-quark mass. We recapitulate upon studies of nucleon electromagnetic form factors, providing a comparison of the ln-weighted ratios of Pauli and Dirac form factors for the neutron and proton.Comment: 9 pages, 2 figures. Contribution to proceedings of Workshop on Exclusive Reactions at High Momentum Transfer, May 21-24, 2007, Jefferson Lab, Newport News, V

    An Expansion Term In Hamilton's Equations

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    For any given spacetime the choice of time coordinate is undetermined. A particular choice is the absolute time associated with a preferred vector field. Using the absolute time Hamilton's equations are −(ÎŽHc)/(ÎŽq)=π˙+Θπ,- (\delta H_{c})/(\delta q)=\dot{\pi}+\Theta\pi, + (\delta H_{c})/(\delta \pi)=\dot{q},where, where \Theta = V^{a}_{.;a}istheexpansionofthevectorfield.Thusthereisahithertounnoticedtermintheexpansionofthepreferredvectorfield.Hamiltonâ€Čsequationscanbeusedtodescribefluidmotion.Inthiscasetheabsolutetimeisthetimeassociatedwiththefluidâ€Čsco−movingvector.Asmeasuredbythisabsolutetimetheexpansiontermispresent.Similarlyincosmology,eachobserverhasaco−movingvectorandHamiltonâ€Čsequationsagainhaveanexpansionterm.ItisnecessarytoincludetheexpansiontermtoquantizesystemssuchastheabovebythecanonicalmethodofreplacingDiracbracketsbycommutators.Hamiltonâ€Čsequationsinthisformdonothaveacorrespondingsympleticform.Replacingtheexpansionbyaparticlenumber is the expansion of the vector field. Thus there is a hitherto unnoticed term in the expansion of the preferred vector field. Hamilton's equations can be used to describe fluid motion. In this case the absolute time is the time associated with the fluid's co-moving vector. As measured by this absolute time the expansion term is present. Similarly in cosmology, each observer has a co-moving vector and Hamilton's equations again have an expansion term. It is necessary to include the expansion term to quantize systems such as the above by the canonical method of replacing Dirac brackets by commutators. Hamilton's equations in this form do not have a corresponding sympletic form. Replacing the expansion by a particle number N\equiv exp(-\int\Theta d \ta)andintroducingtheparticlenumbersconjugatemomentum and introducing the particle numbers conjugate momentum \pi^{N}thestandardsympleticformcanberecoveredwithtwoextrafieldsNand the standard sympletic form can be recovered with two extra fields N and \pi^N$. Briefly the possibility of a non-standard sympletic form and the further possibility of there being a non-zero Finsler curvature corresponding to this are looked at.Comment: 10 page

    Prevalence of working smoke alarms in local authority inner city housing: randomised controlled trial

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    Objectives To identify which type of smoke alarm is most likely to remain working in local authority inner city housing, and to identify an alarm tolerated in households with smokers. Design Randomised controlled trial. Setting Two local authority housing estates in inner London. Participants 2145 households. Intervention Installation of one of five types of smoke alarm (ionisation sensor with a zinc battery; ionisation sensor with a zinc battery and pause button; ionisation sensor with a lithium battery and pause button; optical sensor with a lithium battery; or optical sensor with a zinc battery). Main outcome measure Percentage of homes with any working alarm and percentage in which the alarm installed for this study was working after 15 months. Results 54.4% (1166/2145) of all households and 45.9% (465/1012) of households occupied by smokers had a working smoke alarm. Ionisation sensor, lithium battery, and there being a smoker in the household were independently associated with whether an alarm was working (adjusted odds ratios 2.24 (95% confidence interval 1.75 to 2.87), 2.20 (1.77 to 2.75), and 0.62 (0.52 to 0.74)). The most common reasons for non-function were missing battery (19%), missing alarm (17%), and battery disconnected (4%). Conclusions Nearly half of the alarms installed were not working when tested 15 months later. Type of alarm and power source are important determinants of whether a household had a working alarm

    Thermal OH (1667/65 MHz) Absorption and Nonthermal OH (1720 MHz) Emission Towards the W28 Supernova Remnant

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    The W28 supernova remnant is an excellent prototype for observing shocked gas resulting from the interaction of supernova remnants (SNRs) and adjacent molecular clouds (MCs). We present two new signatures of shocked molecular gas in this remnant. One is the detection of main-line extended OH (1667 MHz) absorption with broad linewidths. The column density of OH estimated from the optical depth profiles is consistent with a theoretical model in which OH is formed behind a C-type shock front. The second is the detection of extended, weak OH (1720 MHz) line emission with narrow linewidth distributed throughout the shocked region of W28. These give observational support to the idea that compact maser sources delineate the brightest component of a much larger region of main line OH absorption and nonthermal OH (1720 MHz) emission tracing the global structure of shocked molecular gas. Main line OH (1665/67) absorption and extended OH (1720 MHz) emission line studies can serve as powerful tools to detect SNR-MC interaction even when bright OH (1720 MHz) masers are absent.Comment: 14 pages, 3 figures, one table, to appear in ApJ (Jan 10, 2003

    Lagrangian description of world-line deviations

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    We introduce a Lagrangian which can be varied to give both the equation of motion and world-line deviations of spinning particles simultaneously.Comment: to appear in IJT
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