456 research outputs found

    Beyond the medical model:Thinking differently about medical education and medical education research

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    Issue: In medical education, teaching is currently viewed as an intervention that causes learning. The task of medical education research is seen as establishing which educational interventions produce the desired learning outcomes. This ‘medical model’ of education does not do justice to the dynamics of education as an open, semiotic, recursive system rather than a closed, causal system. Evidence: Empirical ‘evidence’ of ‘what works’–that is, what is supposed to affect ‘learning’–has become the norm for medical educational improvements, where generalized summary outcomes of research are often presented as must-follow guidelines for myriad future educational situations. Such investigations of educational processes tend to lack an explicit engagement with the purposes of medical education, which we suggest to understand in terms of qualification (the acquisition of knowledge, skills, and understanding), socialization (becoming a member of the professional group) and subjectification (becoming a thoughtful, independent, responsible professional). In addition, investigations of educational processes tend to rely on causal assumptions that are inadequate for capturing the dynamics of educational communication and interaction. Although we see an increasing acknowledgement of the context-dependency of teaching practices toward educational aims, the currently prevailing view in medical education and educational research limits understanding of what is actually going on when educators teach and students participate in medical education–a situation which seriously hinders advancements in the field. Implications: In this paper, we hope to inform discussion about the practice of medical education by proposing to view medical education in terms of three domains of purpose (professional qualification, professional socialization, and professional subjectification) and with full acknowledgement of the dynamics of educational interaction and communication. Such a view implies that curriculum design, pedagogy, assessment, and evaluation should be reoriented to include and integrate all three purposes in educational practice. It also means that medical education research findings cannot be applied in just any teaching context without carefully considering the value of the suggested courses of actions toward the particular educational aims and teaching setting. In addition, medical educational research would need to investigate all three purposes and recognize the openness, semiotic nature, and recursivity of education in offering implic

    A Police Officer’s Tacit Knowledge Inventory (POTKI): Establishing Construct Validity and Exploring Applications

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    Research summarizes the construction of a Police Officer’s Tacit Knowledge Inventory (Inventory), a situational judgment test comprised of knowledge gained on-the-job by experienced police officers, and examines if it can play a role in the development of expertise. Correlation and regression analysis was done to establish the Inventory’s ability to predict post-Academy graduation performance. Results show that Inventory response patterns correlate with Supervisor ratings; and the Inventory responses correctly predict significant differences between novice patrol officers and experienced police officers

    Long-range interactions of metastable helium atoms

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    Polarizabilities, dispersion coefficients, and long-range atom-surface interaction potentials are calculated for the n=2 triplet and singlet states of helium using highly accurate, variationally determined, wave functions.Comment: RevTeX, epsf, 4 fig

    Attraction between DNA molecules mediated by multivalent ions

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    The effective force between two parallel DNA molecules is calculated as a function of their mutual separation for different valencies of counter- and salt ions and different salt concentrations. Computer simulations of the primitive model are used and the shape of the DNA molecules is accurately modelled using different geometrical shapes. We find that multivalent ions induce a significant attraction between the DNA molecules whose strength can be tuned by the averaged valency of the ions. The physical origin of the attraction is traced back either to electrostatics or to entropic contributions. For multivalent counter- and monovalent salt ions, we find a salt-induced stabilization effect: the force is first attractive but gets repulsive for increasing salt concentration. Furthermore, we show that the multivalent-ion-induced attraction does not necessarily correlate with DNA overcharging.Comment: 51 pages and 13 figure

    A High Statistics Search for Electron-Neutrino --> Tau-Neutrino Oscillations

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    We present new limits on nu_e to nu_tau and nu_e to nu_sterile oscillations by searching for electron neutrino dissappearance in the high-energy wide-band CCFR neutrino beam. Sensitivity to nu_tau appearance comes from tau decay modes in which a large fraction of the energy deposited is electromagnetic. The beam is composed primarily of muon neutrinos but this analysis uses the 2.3% electron neutrino component of the beam. Electron neutrino energies range from 30 to 600 GeV and flight lengths vary from 0.9 to 1.4 km. This limit improves the sensitivity of existing limits and obtains a lowest 90% confidence upper limit in sin**2(2*alpha) of 9.9 x 10**(-2) at delta-m**2 of 125 eV**2.Comment: submitted to Phys. Rev. D. Rapid Com

    Nuclear Structure Functions in the Large x Large Q^2 Kinematic Region in Neutrino Deep Inelastic Scattering

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    Data from the CCFR E770 Neutrino Deep Inelastic Scattering (DIS) experiment at Fermilab contain events with large Bjorken x (x>0.7) and high momentum transfer (Q^2>50 (GeV/c)^2). A comparison of the data with a model based on no nuclear effects at large x, shows a significant excess of events in the data. Addition of Fermi gas motion of the nucleons in the nucleus to the model does not explain the excess. Adding a higher momentum tail due to the formation of ``quasi-deuterons'' makes some improvement. An exponentially falling F_2 \propto e^-s(x-x_0) at large x, predicted by ``multi-quark clusters'' and ``few-nucleon correlations'', can describe the data. A value of s=8.3 \pm 0.7(stat.)\pm 0.7(sys.) yields the best agreement with the data.Comment: 4 pages, 4 figures, 1 table. Sibmitted to PR

    A Precise Measurement of the Weak Mixing Angle in Neutrino-Nucleon Scattering

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    We report a precise measurement of the weak mixing angle from the ratio of neutral current to charged current inclusive cross-sections in deep-inelastic neutrino-nucleon scattering. The data were gathered at the CCFR neutrino detector in the Fermilab quadrupole-triplet neutrino beam, with neutrino energies up to 600 GeV. Using the on-shell definition, sin2θW≡1−MW2MZ2{\rm sin ^2\theta_W} \equiv 1 - \frac{{\rm M_W} ^2}{{\rm M_Z} ^2}, we obtain sin2θW=0.2218±0.0025(stat.)±0.0036(exp. syst.)±0.0040(model){\rm sin ^2\theta_W} = 0.2218 \pm 0.0025 ({\rm stat.}) \pm 0.0036 ({\rm exp.\: syst.}) \pm 0.0040 ({\rm model}).Comment: 10 pages, Nevis Preprint #1498 (Submitted to Phys. Rev. Lett.

    A measurement of alphas(Q2)alpha_s(Q^2) from the Gross-Llewellyn Smith Sum Rule

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    We extract a set of values for the Gross-Llewellyn Smith sum rule at different values of 4-momentum transfer squared (Q2Q^{2}), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for 1<Q2<15GeV2/c21 < Q^2 < 15 GeV^2/c^2. A comparison with the order αs3\alpha^{3}_{s} theoretical predictions yields a determination of αs\alpha_{s} at the scale of the Z-boson mass of 0.114±.012.0090.114 \pm^{.009}_{.012}. This measurement provides a new and useful test of perturbative QCD at low Q2Q^2, because of the low uncertainties in the higher order calculations.Comment: 4 pages, 4 figure

    Determination of the Strange Quark Content of the Nucleon from a Next-to-Leading-Order QCD Analysis of Neutrino Charm Production

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    We present the first next-to-leading-order QCD analysis of neutrino charm production, using a sample of 6090 νμ\nu_\mu- and νˉμ\bar\nu_\mu-induced opposite-sign dimuon events observed in the CCFR detector at the Fermilab Tevatron. We find that the nucleon strange quark content is suppressed with respect to the non-strange sea quarks by a factor \kappa = 0.477 \: ^{+\:0.063}_{-\:0.053}, where the error includes statistical, systematic and QCD scale uncertainties. In contrast to previous leading order analyses, we find that the strange sea xx-dependence is similar to that of the non-strange sea, and that the measured charm quark mass, mc=1.70±0.19 GeV/c2m_c = 1.70 \pm 0.19 \:{\rm GeV/c}^2, is larger and consistent with that determined in other processes. Further analysis finds that the difference in xx-distributions between xs(x)xs(x) and xsˉ(x)x\bar s(x) is small. A measurement of the Cabibbo-Kobayashi-Maskawa matrix element ∣Vcd∣=0.232− 0.020+ 0.018|V_{cd}|=0.232 ^{+\:0.018}_{-\:0.020} is also presented. uufile containing compressed postscript files of five Figures is appended at the end of the LaTeX source.Comment: Nevis R#150
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