7,688 research outputs found

    Crystallization and preliminary X-ray diffraction analysis of a biologically active fragment of CD55

    Full text link

    Supervision and Scholarly Writing: Writing to Learn - Learning to Write

    Get PDF
    This paper describes an action research project on postgraduate students’ scholarly writing in which I employed reflective approaches to examine and enhance my postgraduate supervisory practice. My reflections on three distinct cycles of supervision illustrate a shift in thinking about scholarly writing and an evolving understanding of how to support postgraduate students’ writing. These understandings provide the foundation for a future-oriented fourth cycle of supervisory practice, which is characterised by three principles, namely the empowerment of students as writers, the technological context of contemporary writing, and ethical issues in writing

    Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing : observations and modelling of Kangiata Nunaata Sermia, 1859–present

    Get PDF
    Acknowledgements. The authors wish to thank Stephen Price, Mauri Pelto, and the anonymous reviewer for their reviews and comments that helped to improve the manuscript. RACMO2.1 data were provided by Jan van Angelen and Michiel van den Broeke, IMAU, Utrecht University. MAR v3.2 data used for runoff calculations were provided by Xavier Fettweis, Department of Geography, University of Liège. The photogrammetric DEM used in Figs. 1 and 3 was provided by Kurt H. Kjær, Centre for GeoGenetics, University of Copenhagen. This research was financially supported by J. M. Lea’s PhD funding, NERC grant number NE/I528742/1. Support for F. M. Nick was provided through the Conoco-Phillips/Lundin Northern Area Program CRIOS project (Calving Rates and Impact on Sea Level).Peer reviewedPublisher PD

    Reevaluation of patterns of mussel (Mytilus edulis) selection by European Oystercatchers (Haematopus ostralegus)

    Get PDF
    © National Research Council of Canada 2002. Published version reproduced with the permission of the publisher.European Oystercatchers (Haematopus ostralegus) were highly selective towards mussels between 35 and 50 mm in length, and fewer than 5% of mussels taken were below 35 mm or above 50 mm. The oystercatchers selected ventrally thin-shelled mussels, especially if the length was more than 35 mm, regardless of whether they opened the right or left valve of the mussel. The oystercatchers also took mussels that had few barnacles on the ventral surface. Although brown-shelled mussels were rare in the population, oystercatchers showed a strong preference for them. Generally, oystercatchers consumed ventrally flat mussels, especially in the smaller length classes, particularly the most preferred size class, 30–45 mm. Ventral shell thickness and colour had independent effects on mussel selection. The other two variables, number of barnacles and shape of the ventral surface (flat or curved), apparently had no influence on selection on their own, only by way of their association with colour or thickness

    Reclaiming literacies: competing textual practices in a digital higher education

    Get PDF
    This essay examines the implications of the ubiquitous use of the term ‘digital literacies’ in higher education and its increasing alignment with institutional and organisational imperatives. It suggests that the term has been stripped of its provenance and association with disciplinary knowledge production and textual practice. Instead it is called into service rhetorically in order to promote competency based agendas both in and outside the academy. The piece also points to a tendency to position teachers in deficit with regard to their technological capabilities and pay scant attention to their own disciplinary and scholarly practices in a digital world. It concludes that there is a case for building on established theoretical and conceptual frameworks from literacy studies if we wish to integrate advantages of the digital landscape with thoughtful teaching practice

    CaMKII-dependent responses to ischemia and reperfusion challenges in the heart

    Get PDF
    Ischemic heart disease is a leading cause of death, and there is considerable imperative to identify effective therapeutic interventions. Cardiomyocyte Ca2+ overload is a major cause of ischemia and reperfusion injury, initiating a cascade of events culminating in cardiomyocyte death, myocardial dysfunction, and occurrence of lethal arrhythmias. Responsive to fluctuations in intracellular Ca2+, Ca2+/calmodulin-dependent protein kinase II (CaMKII) has emerged as an enticing therapeutic target in the management of ischemic heart injury. CaMKII is activated early in ischemia and to a greater extent in the first few minutes of reperfusion, at a time when reperfusion arrhythmias are particularly prominent. CaMKII phosphorylates and upregulates many of the key proteins involved in intracellular Na+ and Ca2+ loading in ischemia and reperfusion. Experimentally, selective inhibition of CaMKII activity reduces cardiomyocyte death and arrhythmic incidence post-ischemia. New evidence is emerging that CaMKII actions in ischemia and reperfusion involve specific splice variant targeted actions, selective and localized post-translational modifications, and organelle-directed substrate interactions. A more complete mechanistic understanding of CaMKII mode of action in ischemia and reperfusion is required to optimize intervention opportunities. This review summarizes the current experimentally derived understanding of CaMKII participation in mediating the pathophysiology of the heart in ischemia and in reperfusion, and highlights priority future research directions.Centro de Investigaciones Cardiovasculare

    Transversality of Electromagnetic Waves in the Calculus-Based Introductory Physics Course

    Full text link
    Introductory calculus-based physics textbooks state that electromagnetic waves are transverse and list many of their properties, but most such textbooks do not bring forth arguments why this is so. Both physical and theoretical arguments are at a level appropriate for students of courses based on such books, and could be readily used by instructors of such courses. Here, we discuss two physical arguments (based on polarization experiments and on lack of monopole electromagnetic radiation), and the full argument for the transversality of (plane) electromagnetic waves based on the integral Maxwell equations. We also show, at a level appropriate for the introductory course, why the electric and magnetic fields in a wave are in phase and the relation of their magnitudes.Comment: 10 pages, 6 figure

    Magneto-shear modes and a.c. dissipation in a two-dimensional Wigner crystal

    Full text link
    The a.c. response of an unpinned and finite 2D Wigner crystal to electric fields at an angular frequency ω\omega has been calculated in the dissipative limit, ωτ1\omega \tau \ll 1, where τ1\tau ^{-1} is the scattering rate. For electrons screened by parallel electrodes, in zero magnetic field the long-wavelength excitations are a diffusive longitudinal transmission line mode and a diffusive shear mode. A magnetic field couples these modes together to form two new magneto-shear modes. The dimensionless coupling parameter β=2(ct/cl)σxy/σxx\beta =2(c_{t}/c_{l})|\sigma_{xy}/\sigma_{xx}| where ctc_{t} and clc_{l} are the speeds of transverse and longitudinal sound in the collisionless limit and σxy\sigma_{xy} and σxx\sigma_{xx} are the tensor components of the magnetoconductivity. For β1\beta \geqslant 1, both the coupled modes contribute to the response of 2D electrons in a Corbino disk measurement of magnetoconductivity. For β1\beta \gg 1, the electron crystal rotates rigidly in a magnetic field. In general, both the amplitude and phase of the measured a.c. currents are changed by the shear modulus. In principle, both the magnetoconductivity and the shear modulus can be measured simultaneously.Comment: REVTeX, 7 pp., 4 eps figure
    corecore