10,267 research outputs found

    The Effects of Negative Legacies on the Adjustment of Parentally Bereaved Children and Adolescents

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    This is a report of a qualitative analysis of a sample of bereaved families in which one parent died and in which children scored in the clinical range on the Child Behavior Check List. The purpose of this analysis was to learn more about the lives of these children. They were considered to be at risk of developing emotional and behavioral problems associated with the death. We discovered that many of these “high risk” children had a continuing bond with the deceased that was primarily negative and troubling for them in contrast to a comparison group of children not at risk from the same study. Five types of legacies, not mutually exclusive, were identified: health related, role related, personal qualities, legacy of blame, and an emotional legacy. Coping behavior on the part of the surviving parent seemed to make a difference in whether or not a legacy was experienced as negative

    Viscoelastic Phase Patterning in Artificial Protein Hydrogels

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    Viscoelastic forces can affect the dynamics of pattern formation during phase separation in polymeric materials. We programmed an artificial protein hydrogel to undergo viscoelastic phase separation above a critical temperature. Highly dynamic phase patterns that coarsened under the influence of viscoelastic stresses spontaneously emerged in these gels. Local oxidative crosslinking promoted by mild photobleaching could be used to initiate phase separation locally, enabling the creation of non-equilibrium patterns that evolved under the influence of surface tension and viscoelastic stresses to yield dynamic structures of controlled size and shape

    Iso-singlet Down Quark Mixing And CP Violation Experiments

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    We confront the new physics models with extra iso-singlet down quarks in the new CP violation experimental era with sin(2β)\sin{(2\beta)} and ϵ/ϵ\epsilon'/\epsilon measurements, K+π+ννˉK^+ \to \pi^+ \nu \bar{\nu} events, and xsx_s limits. The closeness of the new experimental results to the standard model theory requires us to include full SM amplitudes in the analysis. In models allowing mixing to a new isosinglet down quark, as in E6_6, flavor changing neutral currents are induced that allow a Z0Z^0 mediated contribution to BBˉB-\bar B mixing and which bring in new phases. In (ρ,η)(\rho,\eta), (xs,sin(γ))(x_s,\sin{(\gamma)}), and (xs,sin(2ϕs))(x_s, \sin{(2\phi_s)}) plots we still find much larger regions in the four down quark model than in the SM, reaching down to η0\eta \approx 0, 0sin(γ)10 \leq \sin{(\gamma)} \leq 1, .75sin(2α)0.15-.75 \leq \sin{(2\alpha)} \leq 0.15, and sin(2ϕs)\sin{(2\phi_s)} down to zero, all at 1σ\sigma. We elucidate the nature of the cancellation in an order λ5\lambda^5 four down quark mixing matrix element which satisfies the experiments and reduces the number of independent angles and phases. We also evaluate tests of unitarity for the 3×33\times3 CKM submatrix.Comment: 14 pages, 16 figures, REVTeX

    Prosody Modelling in Concept-to-Speech Generation: Methodological Issues

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    We explore three issues for the development of concept-to-speech (CTS) systems. We identify information available in a language-generation system that has the potential to impact prosody; investigate the role played by different corpora in CTS prosody modelling; and explore different methodologies for learning how linguistic features impact prosody. Our major focus is on the comparison of two machine learning methodologies: generalized rule induction and memory-based learning. We describe this work in the context of multimedia abstract generation of intensive care (MAGIC) data, a system that produces multimedia brings of the status of patients who have just undergone a bypass operation

    Image Coaddition with Temporally Varying Kernels

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    Large, multi-frequency imaging surveys, such as the Large Synaptic Survey Telescope (LSST), need to do near-real time analysis of very large datasets. This raises a host of statistical and computational problems where standard methods do not work. In this paper, we study a proposed method for combining stacks of images into a single summary image, sometimes referred to as a template. This task is commonly referred to as image coaddition. In part, we focus on a method proposed in previous work, which outlines a procedure for combining stacks of images in an online fashion in the Fourier domain. We evaluate this method by comparing it to two straightforward methods through the use of various criteria and simulations. Note that the goal is not to propose these comparison methods for use in their own right, but to ensure that additional complexity also provides substantially improved performance

    Dissipation enhanced vibrational sensing in an olfactory molecular switch

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    Motivated by a proposed olfactory mechanism based on a vibrationally-activated molecular switch, we study electron transport within a donor-acceptor pair that is coupled to a vibrational mode and embedded in a surrounding environment. We derive a polaron master equation with which we study the dynamics of both the electronic and vibrational degrees of freedom beyond previously employed semiclassical (Marcus-Jortner) rate analyses. We show: (i) that in the absence of explicit dissipation of the vibrational mode, the semiclassical approach is generally unable to capture the dynamics predicted by our master equation due to both its assumption of one-way (exponential) electron transfer from donor to acceptor and its neglect of the spectral details of the environment; (ii) that by additionally allowing strong dissipation to act on the odorant vibrational mode we can recover exponential electron transfer, though typically at a rate that differs from that given by the Marcus-Jortner expression; (iii) that the ability of the molecular switch to discriminate between the presence and absence of the odorant, and its sensitivity to the odorant vibrational frequency, are enhanced significantly in this strong dissipation regime, when compared to the case without mode dissipation; and (iv) that details of the environment absent from previous Marcus-Jortner analyses can also dramatically alter the sensitivity of the molecular switch, in particular allowing its frequency resolution to be improved. Our results thus demonstrate the constructive role dissipation can play in facilitating sensitive and selective operation in molecular switch devices, as well as the inadequacy of semiclassical rate equations in analysing such behaviour over a wide range of parameters.Comment: 12 pages, 6 figures, close to published version, comments welcom

    Nonlocal Phases of Local Quantum Mechanical Wavefunctions in Static and Time-Dependent Aharonov-Bohm Experiments

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    We show that the standard Dirac phase factor is not the only solution of the gauge transformation equations. The full form of a general gauge function (that connects systems that move in different sets of scalar and vector potentials), apart from Dirac phases also contains terms of classical fields that act nonlocally (in spacetime) on the local solutions of the time-dependent Schr\"odinger equation: the phases of wavefunctions in the Schr\"odinger picture are affected nonlocally by spatially and temporally remote magnetic and electric fields, in ways that are fully explored. These contributions go beyond the usual Aharonov-Bohm effects (magnetic or electric). (i) Application to cases of particles passing through static magnetic or electric fields leads to cancellations of Aharonov-Bohm phases at the observation point; these are linked to behaviors at the semiclassical level (to the old Werner & Brill experimental observations, or their "electric analogs" - or to recent reports of Batelaan & Tonomura) but are shown to be far more general (true not only for narrow wavepackets but also for completely delocalized quantum states). By using these cancellations, certain previously unnoticed sign-errors in the literature are corrected. (ii) Application to time-dependent situations provides a remedy for erroneous results in the literature (on improper uses of Dirac phase factors) and leads to phases that contain an Aharonov-Bohm part and a field-nonlocal part: their competition is shown to recover Relativistic Causality in earlier "paradoxes" (such as the van Kampen thought-experiment), while a more general consideration indicates that the temporal nonlocalities found here demonstrate in part a causal propagation of phases of quantum mechanical wavefunctions in the Schr\"odinger picture. This may open a direct way to address time-dependent double-slit experiments and the associated causal issuesComment: 49 pages, 1 figure, presented in Conferences "50 years of the Aharonov-Bohm effect and 25 years of the Berry's phase" (Tel Aviv and Bristol), published in Journ. Phys. A. Compared to the published paper, this version has 17 additional lines after eqn.(14) for maximum clarity, and the Abstract has been slightly modified and reduced from the published 2035 characters to the required 1920 character

    Neuropsychological Assessment of Cultrually and Linguistically Diverse Children: A Review of Relevant Issues and Appropraite Methods

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    Drawing from the fields of anatomy, biology, biophysics, ethology, pharmacology, physiology, physiological psychology, and philosophy, neuropsychology is the study of the relationship between human brain function and behavior (Kolb & Whishaw, 2003). According to Lezak (1995), the field of neuropsychology has grown to encompass the diagnosis of individuals, patient care and planning, rehabilitation and treatment evaluation, and research with regard to neuropsychological functioning. Assessment continues to be emphasized as a component of neuropsychology, and it typically involves an evaluation of the following domains: intellectual status, language and academic abilities, executive processes, attention, concentration, learning and memory, visuoconstructive abilities, motor functioning, sensory functioning, and emotional functioning, including mood, behavior, and personality (Groth-Marnat, 2000; Lezak, 1995; Spreen & Strauss, 1998)
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