453 research outputs found

    Are Audience Response Systems Worth the Cost? Comparing Question-Driven Teaching Strategies for Emergency Medical Technician Education

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    Purpose: As Emergency Medical Technician educators develop curricula to meet new national educational standards, effective teaching strategies validated for course content and unique student demographics are warranted. Three methods for answering multiple choice questions presented during lectures were compared: a) Audience Response System (ARS, clickers), b) hand-raising-with-eyes-closed (no-cost option), and c) passive response (no-cost option). The purpose was to determine if using the ARS resulted in improved exam scores. Method: 113 Emergency Medical Technician (EMT) students participated in this cross-over, block randomized, controlled trial, which was incorporated into their Cardiac Emergencies and Pulmonary Emergencies course lectures. Students took pretests, immediate post-tests, and delayed post-tests composed of multiple choice questions that targeted either lower or higher order thinking. Results: For both lectures, there were significant improvements on all immediate post-test scores compared to all pretest scores (p Conclusions: In this cohort, incorporation of no-cost question-driven teaching strategies into lectures was as effective as an ARS at encouraging significant, immediate and sustained improvements in answering multiple choice questions

    A Fluctuation Analysis of the Bolocam 1.1mm Lockman Hole Survey

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    We perform a fluctuation analysis of the 1.1mm Bolocam Lockman Hole Survey, which covers 324 square arcmin to a very uniform point source-filtered RMS noise level of 1.4 mJy/beam. The fluctuation analysis has the significant advantage of utilizing all of the available data. We constrain the number counts in the 1-10 mJy range, and derive significantly tighter constraints than in previous work: the power-law index is 2.7 (+0.18, -0.15), while the amplitude is equal to 1595 (+85,-238) sources per mJy per square degree, or N(>1 mJy) = 940 (+50,-140) sources/square degree (95% confidence). Our results agree extremely well with those derived from the extracted source number counts by Laurent et al (2005). Our derived normalization is about 2.5 times smaller than determined by MAMBO at 1.2mm by Greve et al (2004). However, the uncertainty in the normalization for both data sets is dominated by the systematic (i.e., absolute flux calibration) rather than statistical errors; within these uncertainties, our results are in agreement. We estimate that about 7% of the 1.1mm background has been resolved at 1 mJy.Comment: To appear in the Astrophysical Journal; 22 pages, 9 figure

    Monsoon Intraseasonal Oscillations as simulated by the Superparameterized Community Atmosphere Model

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    The relative success of the Community Atmosphere Model with superparameterized convection (SP-CAM) in simulating the space-time characteristics of the Madden Julian Oscillation encourages us to examine its simulation of the Indian summer monsoon and monsoon intraseasonal oscillations (MISOs). While the model simulates the onset and withdrawal of the Indian monsoon realistically, it has a significant wet bias in boreal summer precipitation over the Asian monsoon region. The space-time characteristics of the MISOs simulated by the SP-CAM are examined in detail and compared with those of the observed MISO to gain insight into the model's bias in simulating the seasonal mean. During northern summer, the model simulates a 20 day mode and a 60 day mode in place of the observed 15 and 45 day modes, respectively. The simulated 20 day mode appears to have no observed analog with a baroclinic vertical structure and strong northward propagation over Indian longitudes. The simulated 60 day mode seems to be a lower-frequency version of the observed 45 day mode with relatively slower northward propagation. The model's underestimation of light rain events and overestimation of heavy rain events are shown to be responsible for the wet bias of the model. More frequent occurrence of heavy rain events in the model is, in turn, related to the vertical structure of the higher-frequency modes. Northward propagation of the simulated 20 day mode is associated with a strong cyclonic vorticity at low levels north of the heating maximum associated with a smaller meridional scale of the simulated mode. The simulated vertical structure of heating indicates a strong maximum in the upper troposphere between 200 and 300 hPa. Such a heating profile seems to generate a higher-order baroclinic mode response with smaller meridional structure, stronger low-level cyclonic vorticity, enhanced low-level moisture convergence, and higher precipitation. Therefore, the vertical structure of heating simulated by the cloud-resolving model within SP-CAM may hold the key for improving the precipitation bias in the model

    The cryomechanical design of MUSIC: a novel imaging instrument for millimeter-wave astrophysics at the Caltech Submillimeter Observatory

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    MUSIC (Multicolor Submillimeter kinetic Inductance Camera) is a new facility instrument for the Caltech Submillimeter Observatory (Mauna Kea, Hawaii) developed as a collaborative effect of Caltech, JPL, the University of Colorado at Boulder and UC Santa Barbara, and is due for initial commissioning in early 2011. MUSIC utilizes a new class of superconducting photon detectors known as microwave kinetic inductance detectors (MKIDs), an emergent technology that offers considerable advantages over current types of detectors for submillimeter and millimeter direct detection. MUSIC will operate a focal plane of 576 spatial pixels, where each pixel is a slot line antenna coupled to multiple detectors through on-chip, lumped-element filters, allowing simultaneously imaging in four bands at 0.86, 1.02, 1.33 and 2.00 mm. The MUSIC instrument is designed for closed-cycle operation, combining a pulse tube cooler with a two-stage Helium-3 adsorption refrigerator, providing a focal plane temperature of 0.25 K with intermediate temperature stages at approximately 50, 4 and 0.4 K for buffering heat loads and heat sinking of optical filters. Detector readout is achieved using semi-rigid coaxial cables from room temperature to the focal plane, with cryogenic HEMT amplifiers operating at 4 K. Several hundred detectors may be multiplexed in frequency space through one signal line and amplifier. This paper discusses the design of the instrument cryogenic hardware, including a number of features unique to the implementation of superconducting detectors. Predicted performance data for the instrument system will also be presented and discussed

    Use of the PIXEL method to investigate gas adsorption in metal–organic frameworks

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    PIXEL has been used to perform calculations of adsorbate-adsorbent interaction energies between a range of metal–organic frameworks (MOFs) and simple guest molecules. Interactions have been calculated for adsorption between MOF-5 and Ar, H(2), and N(2); Zn(2)(BDC)(2)(TED) (BDC = 1,4-benzenedicarboxylic acid, TED = triethylenediamine) and H(2); and HKUST-1 and CO(2). The locations of the adsorption sites and the calculated energies, which show differences in the Coulombic or dispersion characteristic of the interaction, compare favourably to experimental data and literature energy values calculated using density functional theory
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