6,074 research outputs found

    Changes in trabecular bone, hematopoiesis and bone marrow vessels in aplastic anemia, primary osteoporosis, and old age

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    Retrospective histologic analyses of bone biopsies and of post mortem samples from normal persons of different age groups, and of bone biopsies of age- and sex-matched groups of patients with primary osteoporosis and aplastic anemia show characteristic age dependent as well as pathologic changes including atrophy of osseous trabeculae and of hematopoiesis, and changes in the sinusoidal and arterial capillary compartments. These results indicate the possible role of a microvascular defect in the pathogenesis of osteoporosis and aplastic anemia

    Partial survival and inelastic collapse for a randomly accelerated particle

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    We present an exact derivation of the survival probability of a randomly accelerated particle subject to partial absorption at the origin. We determine the persistence exponent and the amplitude associated to the decay of the survival probability at large times. For the problem of inelastic reflection at the origin, with coefficient of restitution rr, we give a new derivation of the condition for inelastic collapse, r<rc=eπ/3r<r_c=e^{-\pi/\sqrt{3}}, and determine the persistence exponent exactly.Comment: 6 page

    Studying the scale and q^2 dependence of K^+-->pi^+e^+e^- decay

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    We extract the K^+-->pi^+e^+e^- amplitude scale at q^2=0 from the recent Brookhaven E865 high-statistics data. We find that the q^2=0 scale is fitted in excellent agreement with the theoretical long-distance amplitude. Lastly, we find that the observed q^2 shape is explained by the combined effect of the pion and kaon form-factor vector-meson-dominance rho, omega and phi poles, and a charged pion loop coupled to a virtual photon-->e^+e^- transition.Comment: 8 pages, 3 figure

    Ways to teach modelling—a 50 year study

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    This article describes a sequence of design research projects, some exploratory others more formal, on the teaching of modelling and the analysis of modelling skills. The initial motivation was the author’s observation that the teaching of applied mathematics in UK high schools and universities involved no active modelling by students, but was entirely focused on their learning standards models of a restricted range of phenomena, largely from Newtonian mechanics. This did not develop the numeracy/mathematical literacy that was so clearly important for future citizens. Early explorations started with modelling workshops with high school teachers and mathematics undergraduates, observed and analysed—in some case using video. The theoretical basis of this work has been essentially heuristic, though the Shell Centre studies included, for example, a detailed analysis of formulation processes that has not, as so often, been directly replicated. Recent work has focused on developing a formative assessment approach to teaching modelling that has proved both successful and popular. Finally, the system-level challenges in trying to establish modelling as an integral part of mathematics curricula are briefly discussed

    2012-04-04 Library Impact Statement for URB 392 Field Experience in Urban Studies

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    Library Impact Statement for URB 392 Field Experience in Urban Studies. No new library resources are required to support this course. Responding Library Faculty member: Joanna M. Burkhardt. Requesting faculty member: Marsh Feldman/ Kat Quin

    2012-03-14 Library Impact Statement for NEU 518/582

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    Library Impact Statement for new course NEU 581/582. No new library resources are necessary to support this course. Responding faculty member: Joanna M. Burkhardt. Requesting faculty member: Linda Hufnagel

    2012-03-14 Library Impact Statement for NEU599 Masters Thesis Research

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    Library Impact Statement for new course NEU 599 Masters Thesis Research. No new library resources are needed to support this course. Responding library faculty member: Joanna M. Burkhardt. Requesting faculty member: Nassar Zawi
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