1,278 research outputs found

    Images and Sequences: A Demonstration Project on the Use of Photography as a Tool for Academic Motivation in Logan Junior High School

    Get PDF
    This is a report of an after-school, non-credit, photo-enrichment course that was developed and offered to students at the Logan Junior High School during the period March 30 through May 6, 1981. The artistic intent of this course was to teach students how to see with a camera, recording images on transparency film, and later arranging transparencies into idea-development or story-telling sequences. The educational intent was to see if such a course would motivate students to perform better in other classes and improve their school relationships in general. The course was of too short a duration to develop any hard facts to support an affirmative answer to the question of educational (behavioral) intent. This is not to say that the course did not motivate such changes, or that the opposite was proven. There was no evidence of improved, static or degraded behavioral states. There was, however, evidence that teacher/ administrator/ counselor biases had something to do with a student\u27s perceived performance. Moreover, there was a degree of unanimity in this respect. Because of the search for motivational factors, I re-discovered Seymour Halleck\u27s construct of stylism, and found it to be applicable to the student population of the project to a large degree. Again, and because this was not a sought-for answer, but a matter of serendipity, I developed no materials to justify the extent, much less the existence of such an observation. And so it is just that: an observation, and probably the most significant finding of the study. Because of the significance of stylism, I have developed the literature search to explain it, and the report of the project to demonstrate this construct in action. It may be that by coming to terms with this construct, educators can develop a protocol for teaching students previously considered to be an educational enigma. Suggestions to this end are offered in the conclusions

    A hypercyclic finite rank perturbation of a unitary operator

    Full text link
    A unitary operator VV and a rank 22 operator RR acting on a Hilbert space \H are constructed such that V+RV+R is hypercyclic. This answers affirmatively a question of Salas whether a finite rank perturbation of a hyponormal operator can be supercyclic.Comment: published in Mathematische Annale

    Telescopic actions

    Get PDF
    A group action H on X is called "telescopic" if for any finitely presented group G, there exists a subgroup H' in H such that G is isomorphic to the fundamental group of X/H'. We construct examples of telescopic actions on some CAT[-1] spaces, in particular on 3 and 4-dimensional hyperbolic spaces. As applications we give new proofs of the following statements: (1) Aitchison's theorem: Every finitely presented group G can appear as the fundamental group of M/J, where M is a compact 3-manifold and J is an involution which has only isolated fixed points; (2) Taubes' theorem: Every finitely presented group G can appear as the fundamental group of a compact complex 3-manifold.Comment: +higher dimension

    Probabilistic classification of acute myocardial infarction from multiple cardiac markers

    Get PDF
    Logistic regression and Gaussian mixture model (GMM) classifiers have been trained to estimate the probability of acute myocardial infarction (AMI) in patients based upon the concentrations of a panel of cardiac markers. The panel consists of two new markers, fatty acid binding protein (FABP) and glycogen phosphorylase BB (GPBB), in addition to the traditional cardiac troponin I (cTnI), creatine kinase MB (CKMB) and myoglobin. The effect of using principal component analysis (PCA) and Fisher discriminant analysis (FDA) to preprocess the marker concentrations was also investigated. The need for classifiers to give an accurate estimate of the probability of AMI is argued and three categories of performance measure are described, namely discriminatory ability, sharpness, and reliability. Numerical performance measures for each category are given and applied. The optimum classifier, based solely upon the samples take on admission, was the logistic regression classifier using FDA preprocessing. This gave an accuracy of 0.85 (95% confidence interval: 0.78–0.91) and a normalised Brier score of 0.89. When samples at both admission and a further time, 1–6 h later, were included, the performance increased significantly, showing that logistic regression classifiers can indeed use the information from the five cardiac markers to accurately and reliably estimate the probability AMI

    Spherical structures on torus knots and links

    Full text link
    The present paper considers two infinite families of cone-manifolds endowed with spherical metric. The singular strata is either the torus knot t(2n+1,2){\rm t}(2n+1, 2) or the torus link t(2n,2){\rm t}(2n, 2). Domains of existence for a spherical metric are found in terms of cone angles and volume formul{\ae} are presented.Comment: 17 pages, 5 figures; typo

    TFPIα Interacts with FVa and FXa to Inhibit Prothrombinase During the Initiation of Coagulation

    Get PDF
    Tissue factor pathway inhibitor α (TFPIα) inhibits prothrombinase, the thrombin-generating complex of factor Xa (FXa) and factor Va (FVa), during the initiation of coagulation. This inhibition requires binding of a conserved basic region within TFPIα to a conserved acidic region in FXa-activated and platelet-released FVa. In this study, the contribution of interactions between TFPIα and the FXa active site and FVa heavy chain to prothrombinase inhibition were examined to further define the inhibitory biochemistry. Removal of FXa active site binding by mutation or by deletion of the second Kunitz domain (K2) of TFPIα produced 17- or 34-fold weaker prothrombinase inhibition, respectively, establishing that K2 binding to the FXa active site is required for efficient inhibition. Substitution of the TFPIα basic region uncharged residues (Leu252, Ile253, Thr255) with Ala (TFPI-AAKA) produced 5.8-fold decreased inhibition. This finding was confirmed using a basic region peptide (Leu252-Lys261) and Ala substitution peptides, which established that the uncharged residues are required for prothrombinase inhibitory activity but not for binding the FVa acidic region. This suggests that the uncharged residues mediate a secondary interaction with FVa subsequent to acidic region binding. This secondary interaction seems to be with the FVa heavy chain, because the FV Leiden mutation weakened prothrombinase inhibition by TFPIα but did not alter TFPI-AAKA inhibitory activity. Thus, efficient inhibition of prothrombinase by TFPIα requires at least 3 intermolecular interactions: (1) the TFPIα basic region binds the FVa acidic region, (2) K2 binds the FXa active site, and (3) Leu252-Thr255 binds the FVa heavy chain
    • …
    corecore