The Design and Validation of the Quantum Mechanics Conceptual Survey

The Quantum Mechanics Conceptual Survey (QMCS) is a 12-question survey of students' conceptual understanding of quantum mechanics. It is intended to be used to measure the relative effectiveness of different instructional methods in modern physics courses. In this paper we describe the design and validation of the survey, a process that included observations of students, a review of previous literature and textbooks and syllabi, faculty and student interviews, and statistical analysis. We also discuss issues in the development of specific questions, which may be useful both for instructors who wish to use the QMCS in their classes and for researchers who wish to conduct further research of student understanding of quantum mechanics. The QMCS has been most thoroughly tested in, and is most appropriate for assessment of (as a posttest only), sophomore-level modern physics courses. We also describe testing with students in junior quantum courses and graduate quantum courses, from which we conclude that the QMCS may be appropriate for assessing junior quantum courses, but is not appropriate for assessing graduate courses. One surprising result of our faculty interviews is a lack of faculty consensus on what topics should be taught in modern physics, which has made designing a test that is valued by a majority of physics faculty more difficult than expected.Comment: Submitted to Physical Review Special Topics: Physics Education Researc

Simulations of thermal Bose fields in the classical limit

We demonstrate that the time-dependent projected Gross-Pitaevskii equation derived earlier [Davis, et al., J. Phys. B 34, 4487 (2001)] can represent the highly occupied modes of a homogeneous, partially-condensed Bose gas. We find that this equation will evolve randomised initial wave functions to equilibrium, and compare our numerical data to the predictions of a gapless, second-order theory of Bose-Einstein condensation [S. A. Morgan, J. Phys. B 33, 3847 (2000)]. We find that we can determine the temperature of the equilibrium state when this theory is valid. Outside the range of perturbation theory we describe how to measure the temperature of our simulations. We also determine the dependence of the condensate fraction and specific heat on temperature for several interaction strengths, and observe the appearance of vortex networks. As the Gross-Pitaevskii equation is non-perturbative, we expect that it can describe the correct thermal behaviour of a Bose gas as long as all relevant modes are highly occupied.Comment: 15 pages, 12 figures, revtex4, follow up to Phys. Rev. Lett. 87 160402 (2001). v2: Modified after referee comments. Extra data added to two figures, section on temperature determination expande

Persuasive health educational materials for colorectal cancer screening

This paper describes an effort to design and evaluate persuasive educational materials for colorectal cancer (CRC) screening. Although CRC screening is highly effective, screening rates in the US remain low. Educational materials represent one strategy for educating patients about screening options and increasing openness to screening. We developed a one-page brochure, leveraging factual information from the Centers for Disease Control and Prevention (CDC) and national guidelines, and strategies for persuasion from the human factors and behavioral economics literatures. We evaluated the resulting brochure with adults over the age of 50. Findings suggest that the educational brochure increases knowledge of CRC and screening options, and increases openness to screening. Furthermore, no significant difference was found between the new one-page brochure and an existing multi-page Screen for Life brochure recommended by the CDC. We interpret these findings as indication that the more practical and potentially less intimidating one-page brochure is as effective as the existing multi-page Screen for Life brochure

CubeSat Reusable Interface Software Platform (CRISP): A Lightweight Message-Bus-Based Flight Software Architecture for Rapid Payload Integration

The Agile Space portfolio of projects at Los Alamos National Laboratory (LANL) develops low-cost, rapidly-deployable space payloads and systems. To increase the agility of future missions, we are developing CRISP: the CubeSat Reusable Interface Software Platform. CRISP provides a lightweight and reusable flight software framework for rapid integration of custom payloads with commercial microsatellite platforms. CRISP cuts development time and costs by reducing non-recurring engineering (NRE); thereby accelerating mission agility. To achieve these goals, CRISP provides a core set of payload/data management functions and abstracts the interface between the bus avionics and the payload(s). CRISP currently consists of the following core software modules: a lightweight and scalable publish-subscribe message bus, a space vehicle interface, volatile and nonvolatile memory management, time and ephemeris distribution, debug printing and logging, and watchdogs. We have also developed a modular ground support utility to ease integration and testing, as well as a template flight software application that can be quickly adapted to new missions. Two upcoming CubeSat missions at LANL have already adopted CRISP: the Experiment for Space Radiation Analysis (ESRA) and the Mini Astrophysical MeV Background Observatory (MAMBO)

Exciting, Cooling And Vortex Trapping In A Bose-Condensed Gas

A straight forward numerical technique, based on the Gross-Pitaevskii equation, is used to generate a self-consistent description of thermally-excited states of a dilute boson gas. The process of evaporative cooling is then modelled by following the time evolution of the system using the same equation. It is shown that the subsequent rethermalisation of the thermally-excited state produces a cooler coherent condensate. Other results presented show that trapping vortex states with the ground state may be possible in a two-dimensional experimental environment.Comment: 9 pages, 7 figures. It's worth the wait! To be published in Physical Review A, 1st February 199

Low-level mediation of directionally specific motion after-effects: motion perception is not necessary

Previous psychophysical experiments with normal human observers have shown that adaptation to a moving dot stream causes directionally specific repulsion in the perceived angle of a subsequently viewed, moving probe. In this paper, we used a 2AFC task with roving pedestals to determine the conditions necessary and sufficient for producing directionally specific repulsion with compound adaptors, each ofwhich contains two oppositely moving, differently colored, component streams. Experiment 1 provides a demonstration of repulsion between single-component adaptors and probes moving at approximately 90° or 270°. In Experiment 2 oppositely moving dots in the adaptor were paired to preclude the appearance of motion. Nonetheless, repulsion remained strong when the angle betweeneach probe stream and one component was approximately 30°. In Experiment 3 adapting dot-pairs were kept stationary during their limited lifetimes. Their orientation content alone proved insufficient for producing repulsion. In Experiments 4-6 the angle between probe and both adapting components was approximately 90°or 270°. Directional repulsion was found when observers were asked to visually track one of the adapting components (Experiment 6), but not when observers were asked to attentionally track it (Experiment 5), nor while passively viewing the adaptor (Experiment 4). Our results are consistent with a low-level mechanism for motion adaptation. It is not selective for stimulus color and it is not susceptible to attentional modulation.The most likely cortical locus of adaptation is area V1

Undergraduate medical student perceptions and use of Evidence Based Medicine: A qualitative study

<p>Abstract</p> <p>Background</p> <p>Many medical schools teach the principles of Evidence Based Medicine (EBM) as a subject within their medical curriculum. Few studies have explored the barriers and enablers that students experience when studying medicine and attempting to integrate EBM in their clinical experience. The aim of this study was to identify undergraduate medical student perceptions of EBM, including their current use of its principles as students and perceived future use as clinicians.</p> <p>Methods</p> <p>Third year medical students were recruited via email to participate in focus group discussions. Four focus groups were conducted separately across four hospital sites. All focus groups were conducted by the same facilitator. All discussions were transcribed verbatim, and analysed independently by the two authors according to the principles of thematic analysis.</p> <p>Results</p> <p>Focus group discussions were conducted with 23 third-year medical students, representing three metropolitan and one rural hospital sites. Five key themes emerged from the analysis of the transcripts: (1) Rationale and observed use of EBM in practice, (2) Current use of EBM as students, (3) Perceived use of EBM as future clinicians, (4) Barriers to practicing EBM, and (5) Enablers to facilitate the integration of EBM into clinical practice. Key facilitators for promoting EBM to students include competency in EBM, mentorship and application to clinical disciplines. Barriers to EBM implementation include lack of visible application by senior clinicians and constraints by poor resourcing.</p> <p>Conclusions</p> <p>The principles and application of EBM is perceived by medical students to be important in both their current clinical training and perceived future work as clinicians. Future research is needed to identify how medical students incorporate EBM concepts into their clinical practice as they gain greater clinical exposure and competence.</p

Observation of metastable states in spinor Bose-Einstein condensates

Bose-Einstein condensates have been prepared in long-lived metastable excited states. Two complementary types of metastable states were observed. The first is due to the immiscibility of multiple components in the condensate, and the second to local suppression of spin-relaxation collisions. Relaxation via re-condensation of non-condensed atoms, spin relaxation, and quantum tunneling was observed. These experiments were done with F=1 spinor Bose-Einstein condensates of sodium confined in an optical dipole trap.Comment: 3 figures included in paper, fourth figure separat

Stability of stationary states in the cubic nonlinear Schroedinger equation: applications to the Bose-Einstein condensate

The stability properties and perturbation-induced dynamics of the full set of stationary states of the nonlinear Schroedinger equation are investigated numerically in two physical contexts: periodic solutions on a ring and confinement by a harmonic potential. Our comprehensive studies emphasize physical interpretations useful to experimentalists. Perturbation by stochastic white noise, phase engineering, and higher order nonlinearity are considered. We treat both attractive and repulsive nonlinearity and illustrate the soliton-train nature of the stationary states.Comment: 9 pages, 11 figure

Thermodynamics of an interacting trapped Bose-Einstein gas in the classical field approximation

We present a convenient technique describing the condensate in dynamical equilibrium with the thermal cloud, at temperatures close to the critical one. We show that the whole isolated system may be viewed as a single classical field undergoing nonlinear dynamics leading to a steady state. In our procedure it is the observation process and the finite detection time that allow for splitting the system into the condensate and the thermal cloud.Comment: 4 pages, 4 eps figures, final versio