173 research outputs found

    Teaching-the purpose of repeatable testing: Response to comment of J. D. Edmonds

    Get PDF
    It is not clear that the comment Grading and Regrading \u27 has very much to do with our article.\u27 The comment seems rather to be a nostalgic statement recalling the good old days when with glee we cracked the whip and the students either shaped up or shipped out. Our purpose in doing repeatable testing was not to become a do your own thing force, to raise everyone\u27s grades, to achieve well defined educational objectives like teaching the solution to the inclined plane problem, to do away with certification, and most definitely our purpose was not to replace teachers with computer-programmed instruction. Our purpose was in fact really rather simple. It was to try to teach more physics. Dr. Edmond\u27s comment has not addressed the premise of our paper, which is that people learn from their mistakes (even in the real world). We have used nothing but the old guard establishment tool of testing as a measure of content mastery. Once the test is established as the measure of content mastery, how large a jump is it to the statement that if you do better on the next exam you will have mastered more content? If we can improve the teaching of physics and make the students feel good about learning at the same time, we should be willing to give up a few of our old sadistic pleasures

    Splitting of the Dipole and Spin-Dipole Resonances

    Full text link
    Cross sections for the 90,92,94Zr(p,n) reactions were measured at energies of 79.2 and 119.4 MeV. A phenomenological model was developed to describe the variation with bombarding energy of the position of the L=1 peak observed in these and other (p,n) reactions. The model yields the splitting between the giant dipole and giant spin dipole resonances. Values of these splittings are obtained for isotopes of Zr and Sn and for 208Pb.Comment: 14 pages, 4 figure

    Asteroseismology of Eclipsing Binary Stars in the Kepler Era

    Full text link
    Eclipsing binary stars have long served as benchmark systems to measure fundamental stellar properties. In the past few decades, asteroseismology - the study of stellar pulsations - has emerged as a new powerful tool to study the structure and evolution of stars across the HR diagram. Pulsating stars in eclipsing binary systems are particularly valuable since fundamental properties (such as radii and masses) can determined using two independent techniques. Furthermore, independently measured properties from binary orbits can be used to improve asteroseismic modeling for pulsating stars in which mode identifications are not straightforward. This contribution provides a review of asteroseismic detections in eclipsing binary stars, with a focus on space-based missions such as CoRoT and Kepler, and empirical tests of asteroseismic scaling relations for stochastic ("solar-like") oscillations.Comment: 28 pages, 12 figures, 2 tables; Proceedings of the AAS topical conference "Giants of Eclipse" (AASTCS-3), July 28 - August 2 2013, Monterey, C

    Making things happen : a model of proactive motivation

    Get PDF
    Being proactive is about making things happen, anticipating and preventing problems, and seizing opportunities. It involves self-initiated efforts to bring about change in the work environment and/or oneself to achieve a different future. The authors develop existing perspectives on this topic by identifying proactivity as a goal-driven process involving both the setting of a proactive goal (proactive goal generation) and striving to achieve that proactive goal (proactive goal striving). The authors identify a range of proactive goals that individuals can pursue in organizations. These vary on two dimensions: the future they aim to bring about (achieving a better personal fit within one’s work environment, improving the organization’s internal functioning, or enhancing the organization’s strategic fit with its environment) and whether the self or situation is being changed. The authors then identify “can do,” “reason to,” and “energized to” motivational states that prompt proactive goal generation and sustain goal striving. Can do motivation arises from perceptions of self-efficacy, control, and (low) cost. Reason to motivation relates to why someone is proactive, including reasons flowing from intrinsic, integrated, and identified motivation. Energized to motivation refers to activated positive affective states that prompt proactive goal processes. The authors suggest more distal antecedents, including individual differences (e.g., personality, values, knowledge and ability) as well as contextual variations in leadership, work design, and interpersonal climate, that influence the proactive motivational states and thereby boost or inhibit proactive goal processes. Finally, the authors summarize priorities for future researc

    T cell receptor alpha variable 12-2 bias in the immunodominant response to Yellow fever virus.

    Get PDF
    The repertoire of human ιβ T-cell receptors (TCRs) is generated via somatic recombination of germline gene segments. Despite this enormous variation, certain epitopes can be immunodominant, associated with high frequencies of antigen-specific T cells and/or exhibit bias toward a TCR gene segment. Here, we studied the TCR repertoire of the HLA-A*0201-restricted epitope LLWNGPMAV (hereafter, A2/LLW) from Yellow Fever virus, which generates an immunodominant CD8 <sup>+</sup> T cell response to the highly effective YF-17D vaccine. We discover that these A2/LLW-specific CD8 <sup>+</sup> T cells are highly biased for the TCR ι chain TRAV12-2. This bias is already present in A2/LLW-specific naïve T cells before vaccination with YF-17D. Using CD8 <sup>+</sup> T cell clones, we show that TRAV12-2 does not confer a functional advantage on a per cell basis. Molecular modeling indicated that the germline-encoded complementarity determining region (CDR) 1ι loop of TRAV12-2 critically contributes to A2/LLW binding, in contrast to the conventional dominant dependence on somatically rearranged CDR3 loops. This germline component of antigen recognition may explain the unusually high precursor frequency, prevalence and immunodominance of T-cell responses specific for the A2/LLW epitope

    Track D Social Science, Human Rights and Political Science

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd
    • …
    corecore