2,568 research outputs found

    Evaluating Instructive Feedback as a Maintenance Procedure During Discrete-Trial Instruction

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    Instructive feedback is a procedure that involves presenting secondary targets during a learning trial. The child is not required to respond to the secondary targets, and if the child does respond the therapist does not provide differential consequences. Instructive feedback has been shown to increase the effectiveness and efficiency of discrete-trial instruction for children with autism. We evaluated maintenance of previously learned skills when they were and were not presented as instructive feedback during teaching sessions. We used an adapted-alternating treatments design to compare three conditions, in which previously learned skills were presented as secondary targets five times per week, once per week, and when previously learned skills were not presented during the learning trial. We measured the percentage of trials with a correct response during maintenance and follow-up sessions, which we conducted for nine weeks. We also measured the number of sessions and amount of teaching time required for participants to meet a pre-specified mastery criterion in conditions with and without instructive feedback. Finally, we measured the percentage of trials in which a participant repeated the therapist\u27s presentation of the secondary target. Results indicate that presenting target responses as instructive feedback did not improve or reduce the efficiency of teaching sessions with non-target responses. We will discuss clinical implications, limitations, and suggestions for future research

    Using Pilot Systems to Execute Many Task Workloads on Supercomputers

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    High performance computing systems have historically been designed to support applications comprised of mostly monolithic, single-job workloads. Pilot systems decouple workload specification, resource selection, and task execution via job placeholders and late-binding. Pilot systems help to satisfy the resource requirements of workloads comprised of multiple tasks. RADICAL-Pilot (RP) is a modular and extensible Python-based pilot system. In this paper we describe RP's design, architecture and implementation, and characterize its performance. RP is capable of spawning more than 100 tasks/second and supports the steady-state execution of up to 16K concurrent tasks. RP can be used stand-alone, as well as integrated with other application-level tools as a runtime system

    Defining Inclusionary Practices in Catholic Schools

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    The purpose of this article is to provide Catholic educators, administrators, families, and broader parish communities an understanding of critical elements required to effectively include all students, particularly those with disabilities, in Catholic schools. With an understanding that Catholic schools enroll and will continue to add not only students with disabilities, but also other students who may struggle with learning in some manner, the Catholic school community needs to keep abreast of effective practices that facilitate meaningful inclusion. This is especially relevant for those Catholic families who desire a Catholic education for their children with disabilities, as well as their typically developing children. This article seeks to: (a) offer a rationale for the need to include all learners in our Catholic schools through the reinforcement of Catechetical teachings, (b) define inclusion in Catholic education, (c) outline characteristics of high quality, inclusive schools, (d) review relevant research on inclusion that is applicable to the needs of our Catholic school environments, and (e) provide a case study of an effective, inclusive Catholic school to further contextualize to the field what is not only possible, even given limited resources, but what is happening in today’s Catholic school settings

    Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

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    Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron momenta sampled during these simulations were analyzed and justified using theoretically determined boundaries. We present a complete set of tables suited for mean free path calculations of Monte Carlo simulations of the cyclotron scattering process for conditions expected in typical X-ray pulsar accretion columns (0.01<B/B_{crit}<=0.12, where B_{crit}=4.413x10^{13} G and 3keV<=kT<15keV). The sampling of the tables is chosen such that the results have an estimated relative error of at most 1/15 for all points in the grid. The tables are available online at http://www.sternwarte.uni-erlangen.de/research/cyclo.Comment: A&A, in pres

    Development of an Understanding of Reactive Mercury in Ambient Air: A Review

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    This review focuses on providing the history of measurement efforts to quantify and characterize the compounds of reactive mercury (RM), and the current status of measurement methods and knowledge. RM collectively represents gaseous oxidized mercury (GOM) and that bound to particles. The presence of RM was first recognized through measurement of coal-fired power plant emissions. Once discovered, researchers focused on developing methods for measuring RM in ambient air. First, tubular KCl-coated denuders were used for stack gas measurements, followed by mist chambers and annular denuders for ambient air measurements. For ~15 years, thermal desorption of an annular KCl denuder in the Tekran® speciation system was thought to be the gold standard for ambient GOM measurements. Research over the past ~10 years has shown that the KCl denuder does not collect GOM compounds with equal efficiency, and there are interferences with collection. Using a membrane-based system and an automated system—the Detector for Oxidized mercury System (DOHGS)—concentrations measured with the KCl denuder in the Tekran speciation system underestimate GOM concentrations by 1.3 to 13 times. Using nylon membranes it has been demonstrated that GOM/RM chemistry varies across space and time, and that this depends on the oxidant chemistry of the air. Future work should focus on development of better surfaces for collecting GOM/RM compounds, analytical methods to characterize GOM/RM chemistry, and high-resolution, calibrated measurement systems

    Spectral and Timing Analysis of the accretion-powered pulsar 4U 1626-67 observed with Suzaku and NuSTAR

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    We present an analysis of the spectral shape and pulse profile of the accretion-powered pulsar 4U 1626-67 observed with Suzaku and NuSTAR during a spin-up state. The pulsar, which experienced a torque reversal to spin-up in 2008, has a spin period of 7.7 s. Comparing the phase-averaged spectra obtained with Suzaku in 2010 and with NuSTAR in 2015, we find that the spectral shape changed between the two observations: the 3-10 keV flux increased by 5% while the 30-60 keV flux decreased significantly by 35%. Phase-averaged and phase-resolved spectral analysis shows that the continuum spectrum observed by NuSTAR is well described by an empirical NPEX continuum with an added broad Gaussian emission component around the spectral peak at 20 keV. Taken together with the observed Pdot value obtained from Fermi/GBM, we conclude that the spectral change between the Suzaku and NuSTAR observations was likely caused by an increase of the accretion rate. We also report the possible detection of asymmetry in the profile of the fundamental cyclotron line. Furthermore, we present a study of the energy-resolved pulse profiles using a new relativistic ray tracing code, where we perform a simultaneous fit to the pulse profiles assuming a two-column geometry with a mixed pencil- and fan-beam emission pattern. The resulting pulse profile decompositions enable us to obtain geometrical parameters of accretion columns (inclination, azimuthal and polar angles) and a fiducial set of beam patterns. This information is important to validate the theoretical predictions from radiation transfer in a strong magnetic field.Comment: 19 pages, 14 figures, Accepted for publication in ApJ on May 5, 201
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