12,364 research outputs found

    The Challenge of A Black Presidential Candidacy

    Get PDF

    The Challenge of A Black Presidential Candidacy (1984)

    Get PDF

    Floccinaucinihilipilification: Semisimple extensions of the Standard Model gauge algebra

    Full text link
    We show how one may classify all semisimple algebras containing the su(3)⊕su(2)⊕u(1)\mathfrak{su}(3)\oplus \mathfrak{su}(2) \oplus \mathfrak{u}(1) symmetry of the Standard Model and acting on some given matter sector, enabling theories beyond the Standard Model with unification (partial or total) of symmetries (gauge or global) to be catalogued. With just a single generation of Standard Model fermions plus a singlet neutrino, the only {gauge} symmetries correspond to the well-known algebras su(5),so(10),\mathfrak{su}(5),\mathfrak{so}(10), and su(4)⊕su(2)⊕su(2)\mathfrak{su}(4)\oplus \mathfrak{su}(2) \oplus \mathfrak{su}(2), but with two or more generations a limited number of exotic symmetries mixing flavour, colour, and electroweak degrees of freedom become possible. We provide a complete catalogue in the case of 3 generations or fewer and outline how our method generalizes to cases with additional matter.Comment: 13 pages. v3: Minor corrections due to a coding error in the lists of maximal and minimal algebras; references adde

    Evaluation of a new clinical performance assessment tool: A reliability study

    Get PDF
    Clinical practice is an essential requirement of any graduate physiotherapy programme. For this purpose, valid and reliable assessment tools are paramount for the measurement of key competencies in the real-world setting. This study aims to determine the internal consistency and inter-rater reliability of a newly developed and validated clinical performance assessment form. A cross-sectional quantitative research design was used, which included paired evaluations of 32 (17 treatment and 15 assessment) student examinations performed by two independent clinical educators. Chronbachs alpha was computed to assess internal consistency and intraclass correlation coefficient (ICC’s) with confidence intervals of 95% were computed to determine the percentage agreement between paired examiners. The degree of internal consistency was substantial for all key performance areas of both examinations, except for time and organisational management (0.21) and professionalism (0.42) in the treatment and evaluation examinations respectively. The overall internal consistency was 0.89 and 0.73 for both treatment and assessment examinations, indicating substantial agreement. With regard to agreement between raters, the ICC’s for the overall marks were 0.90 and 0.97 for both treatment and assessment examinations. Clinical educators demonstrated a high level of reliability in the assessment of students’ competence using the newly developed clinical performance assessment form. These findings greatly underscore the reliability of results obtained through observation of student examinations, and add another tool to the basket of ensuring quality assurance in physiotherapy clinical practice assessment

    A disrupted circumstellar torus inside eta Carinae's Homunculus Nebula

    Get PDF
    We present thermal infrared images of the bipolar nebula surrounding eta Carinae at six wavelengths from 4.8 to 24.5 microns. These were obtained with the MIRAC3 camera system at the Magellan Observatory. Our images reveal new intricate structure in the bright core of the nebula, allowing us to re-evaluate interpretations of morphology seen in images with lower resolution. Complex structures in the core might not arise from a pair of overlapping rings or a cool (110 K) and very massive dust torus, as has been suggested recently. Instead, it seems more likely that the arcs and compact knots comprise a warm (350 K) disrupted torus at the intersection of the larger polar lobes. Some of the arcs appear to break out of the inner core region, and may be associated with equatorial features seen in optical images. The torus could have been disrupted by a post-eruption stellar wind, or by ejecta from the Great Eruption itself if the torus existed before that event. Kinematic data are required to rule out either possibility.Comment: 8 pages, 3 figures (Fig. 1 in color); to appear in ApJ Letter
    • …
    corecore