648 research outputs found

    The Culturally-adapted Early Pathways Program for Young Latino Children in Poverty: A Randomized Controlled Trial

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    This study used a randomized controlled design with treatment and wait-list conditions to evaluate the efficacy of a culturally adapted version of the Early Pathways program (EP; Fox & Gresl, 2014), an in-home, parentā€“child therapy program with 137 at-risk Latino children under the age of 6 referred for severe behavior and emotional problems, such as aggression, oppositional behavior, self-injury, and property destruction. EP directly engaged the parentā€“child dyad, emphasizing parent-directed training, child-led play, psychoeducation, and cognitiveā€“behavioral strategies. Cultural modifications included establishing community partnerships to identify Latino family needs, translation of materials, offering bilingual services, acculturation assessment, and cultural competence training. Multivariate analyses of covariance (MANCOVA) revealed significant differences between the immediate and delayed treatment groups on all posttest measures with the pretest scores as covariates. After the delayed group completed treatment, repeated measures, multivariate analyses of variance (MANOVA) showed significant improvement for both groups on all measures with maintenance at 4- to 6-week follow-up. Outcomes included reduced child behavior problems, increased child prosocial behaviors, improved caregiver limit setting, enhanced caregiver nurturing, improved parentā€“child relationships, and a decrease in clinical diagnoses following treatment. This study highlights the efficacy of using culturally adapted early intervention services for young Latino children in poverty referred for significant behavior and emotional problems

    A Parent-Child Therapy Program for Latino Families

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    This study used a randomized control design with treatment and wait-list conditions to evaluate the efficacy of a culturally-adapted version of the Early Pathways program (Fox & Gresl, 2014), an in-home, parent-child therapy program with 137 at-risk Latino children under the age of six referred for severe behavior and emotional problems, such as aggression, oppositional behavior, self-injury and property destruction. Early Pathways directly engaged the parent-child dyad, emphasizing parent-directed training and child-engagement activities, such as psycho-education, child-led play, and cognitive-behavioral strategies. Cultural modifications included establishing community partnerships to identify Latino family needs, translation of materials, offering bilingual services, acculturation assessment, and cultural competence training. Multivariate analyses of covariance (MANCOVA) revealed significant differences between the immediate and delayed treatment groups on all post-test measures with the pre-test scores as covariates. After the delayed group completed treatment, repeated measures, multivariate analyses of variance (MANOVA) showed significant improvement for both groups on all measures with maintenance at four- to six-week follow-up. Outcomes included reduced child behavior problems, increased child pro-social behaviors, improved caregiver discipline, enhanced caregiver nurturing, improved parent-child relationships, and a decrease in clinical diagnoses following treatment. This study offers guidance for developing culturally-adapted early intervention services for young Latino children in poverty referred for severe behavior problems

    Treatment Outcomes for At-Risk Young Children With Behavior Problems: Toward a New Definition of Success

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    This study examined the outcomes of Early Pathways (EP), an in-home parentā€“child therapy program with 447 at-risk children younger than 5 years of age who were referred for severe behavior and emotional problems, such as aggression, oppositional behavior, and separation anxiety. EP emphasized parent-directed training of child behavior strategies including psychoeducation regarding child development, child-led play, and cognitive-behavioral techniques. Outcomes were assessed using a unique 2-dimensional definition of treatment completion, which consisted of treatment duration and an assessment of reliable change for the primary outcome measure of child behavior problems. Results showed that the majority of children (63.4%) met or exceeded treatment completion. In addition, repeated-measures multivariate analyses of variance at pretest, posttest, and follow-up revealed increased child prosocial behaviors, reduced child behavior problems, improved caregiver nurturing, an increase in parentsā€™ developmentally appropriate expectations of children, improved parentā€“child relationships, and a decrease in clinical diagnoses following treatment. This study offers guidance for developing effective early-intervention services for families in poverty to enhance outcomes for their young children. Along with its existing large-scale, community-based effectiveness studies, future research should establish additional statistical support including a randomized, waitlist control design of EP

    Exploration Laboratory Analysis - ARC

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    The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk, Risk of Inability to Adequately Treat an Ill or Injured Crew Member, and ExMC Gap 4.05: Lack of minimally invasive in-flight laboratory capabilities with limited consumables required for diagnosing identified Exploration Medical Conditions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability in future exploration missions. Mission architecture poses constraints on equipment and procedures that will be available to treat evidence-based medical conditions according to the Space Medicine Exploration Medical Conditions List (SMEMCL). The SMEMCL provided diagnosis and treatment for the evidence-based medical conditions and hence, a basis for developing ELA functional requirements

    Dynamical Synapses Enhance Neural Information Processing: Gracefulness, Accuracy and Mobility

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    Experimental data have revealed that neuronal connection efficacy exhibits two forms of short-term plasticity, namely, short-term depression (STD) and short-term facilitation (STF). They have time constants residing between fast neural signaling and rapid learning, and may serve as substrates for neural systems manipulating temporal information on relevant time scales. The present study investigates the impact of STD and STF on the dynamics of continuous attractor neural networks (CANNs) and their potential roles in neural information processing. We find that STD endows the network with slow-decaying plateau behaviors-the network that is initially being stimulated to an active state decays to a silent state very slowly on the time scale of STD rather than on the time scale of neural signaling. This provides a mechanism for neural systems to hold sensory memory easily and shut off persistent activities gracefully. With STF, we find that the network can hold a memory trace of external inputs in the facilitated neuronal interactions, which provides a way to stabilize the network response to noisy inputs, leading to improved accuracy in population decoding. Furthermore, we find that STD increases the mobility of the network states. The increased mobility enhances the tracking performance of the network in response to time-varying stimuli, leading to anticipative neural responses. In general, we find that STD and STP tend to have opposite effects on network dynamics and complementary computational advantages, suggesting that the brain may employ a strategy of weighting them differentially depending on the computational purpose.Comment: 40 pages, 17 figure

    Dynamics of Neural Networks with Continuous Attractors

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    We investigate the dynamics of continuous attractor neural networks (CANNs). Due to the translational invariance of their neuronal interactions, CANNs can hold a continuous family of stationary states. We systematically explore how their neutral stability facilitates the tracking performance of a CANN, which is believed to have wide applications in brain functions. We develop a perturbative approach that utilizes the dominant movement of the network stationary states in the state space. We quantify the distortions of the bump shape during tracking, and study their effects on the tracking performance. Results are obtained on the maximum speed for a moving stimulus to be trackable, and the reaction time to catch up an abrupt change in stimulus.Comment: 6 pages, 7 figures with 4 caption

    A Moving Bump in a Continuous Manifold: A Comprehensive Study of the Tracking Dynamics of Continuous Attractor Neural Networks

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    Understanding how the dynamics of a neural network is shaped by the network structure, and consequently how the network structure facilitates the functions implemented by the neural system, is at the core of using mathematical models to elucidate brain functions. This study investigates the tracking dynamics of continuous attractor neural networks (CANNs). Due to the translational invariance of neuronal recurrent interactions, CANNs can hold a continuous family of stationary states. They form a continuous manifold in which the neural system is neutrally stable. We systematically explore how this property facilitates the tracking performance of a CANN, which is believed to have clear correspondence with brain functions. By using the wave functions of the quantum harmonic oscillator as the basis, we demonstrate how the dynamics of a CANN is decomposed into different motion modes, corresponding to distortions in the amplitude, position, width or skewness of the network state. We then develop a perturbative approach that utilizes the dominating movement of the network's stationary states in the state space. This method allows us to approximate the network dynamics up to an arbitrary accuracy depending on the order of perturbation used. We quantify the distortions of a Gaussian bump during tracking, and study their effects on the tracking performance. Results are obtained on the maximum speed for a moving stimulus to be trackable and the reaction time for the network to catch up with an abrupt change in the stimulus.Comment: 43 pages, 10 figure

    Valley formation and methane precipitation rates on Titan

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    Branching valley networks near the landing site of the Huygens probe on Titan imply that fluid has eroded the surface. The fluid was most likely methane, which forms several percent of Titan's atmosphere and can exist as a liquid at the surface. The morphology of the valley networks and the nature of Titan's surface environment are inconsistent with a primary valley formation process involving thermal, chemical, or seepage erosion. The valleys were more likely eroded mechanically by surface runoff associated with methane precipitation. If mechanical erosion did occur, the flows must first have been able to mobilize any sediment accumulated in the valleys. We develop a model that links precipitation, open-channel flow, and sediment transport to calculate the minimum precipitation rate required to mobilize sediment and initiate erosion. Using data from two monitored watersheds in the Alps, we show that the model is able to predict precipitation rates in small drainage basins on Earth. The calculated precipitation rate is most sensitive to the sediment grain size. For a grain diameter of 1ā€“10 cm, a range that brackets the median size observed at the Huygens landing site, the minimum precipitation rate required to mobilize sediment in the nearby branching networks is 0.5ā€“15 mm hr^(āˆ’1). We show that this range is reasonable given the abundance of methane in Titan's atmosphere. These minimum precipitation rates can be compared with observations of tropospheric cloud activity and estimates of long-term methane precipitation rates to further test the hypothesis that runoff eroded the valleys

    Synchrotron Cooling in Energetic Gamma-Ray Bursts Observed by the Fermi Gamma-Ray Burst Monitor

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    We study the time-resolved spectra of eight GRBs observed by Fermi GBM in its first five years of mission, with 1 keV - 1 MeV fluence f>1.0Ɨ10āˆ’4f>1.0\times10^{-4} erg cmāˆ’2^{-2} and signal-to-noise level S/Nā‰„10.0\text{S/N}\geq10.0 above 900 keV. We aim to constrain in detail the spectral properties of GRB prompt emission on a time-resolved basis and to discuss the theoretical implications of the fitting results in the context of various prompt emission models. We perform time-resolved spectral analysis using a variable temporal binning technique according to optimal S/N criteria, resulting in a total of 299 time-resolved spectra. We fit the Band function to all spectra and obtain the distributions for the low-energy power-law index Ī±\alpha, the high-energy power-law index Ī²\beta, the peak energy in the observed Ī½FĪ½\nu F_\nu spectrum EpE_\text{p}, and the difference between the low- and high-energy power-law indices Ī”s=Ī±āˆ’Ī²\Delta s=\alpha-\beta. Using the distributions of Ī”s\Delta s and Ī²\beta, the electron population index pp is found to be consistent with the "moderately fast" scenario which fast- and slow-cooling scenarios cannot be distinguished. We also apply a physically motivated synchrotron model, which is a triple power-law with constrained power-law indices and a blackbody component, to test for consistency with a synchrotron origin for the prompt emission and obtain the distributions for the two break energies Eb,1E_\text{b,1} and Eb,2E_\text{b,2}, the middle segment power-law index Ī²\beta, and the Planck function temperature kTkT. A synchrotron model is found consistent with the majority of time-resolved spectra for these eight energetic Fermi GBM bursts with good high-energy photon statistics, as long as both the cooling and injection break are included and the leftmost spectral slope is lifted either by inclusion of a thermal component or when an evolving magnetic field is accounted for.Comment: 20 pages, 7 figures, 8 tables, accepted for publication in A&
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