3,877 research outputs found

    Podcasting, pupils and pre-service-teachers

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    This Action Research conforms to Cohen's definition (2000) as "small scale intervention in the functioning of the real world and a close examination of the effects of such an intervention." It is a pilot study that uses a small, but representative group of students with a view to establishing generalisations about the wider applicability of the methods explored. (Burns, 2000, pp. 460-461) The authors examine the use of podcasting - a popular contemporary method of delivering audio content through computers and portable media players. Many rationales for their use in education can be advanced, for example Freedman (2006) lists sixteen reasons including the potential for students to access the podcasts at their own convenience. See also Maag (2006) and Kollar (2006). The study group included six undergraduate, pre-service science teachers who were completing a BSc (Honours) in Bioscience with Teaching. They had previously undertaken course assessments which incorporated presentations to peers and tutors. The pre-service science teachers had already completed block and serial school placements and were considered as being skilled in planning and delivering short presentations as part of their classroom practice. Their presentations had invariably been supported with well constructed and illustrated PowerPoint presentations. The Benchmark Standards for Initial Teacher Education (ITE) (General Teaching Council for Scotland & Quality Assurance Agency for Higher Education, 2006) relate to classroom to whole school standards for ITE in Scotland. They make specific reference to the significance and the expectations for Information and Communication Technology (ICT). ICT is viewed (paragraph 3.1) as a "Core professional interest" and student teachers should be "undertaking a range of approaches to teaching to facilitate the learning of pupils, including the appropriate use of information and communications technology". Also, ICT provides the potential "to contribute to a process of change". Boud (2000) was critical of assessment practices in higher education institutions and suggested "The purposes of assessment should be extended to include the preparation of students for sustainable assessment". Draper and Maguire (2006) explored the use of podcasts in campus based teaching with first year undergraduates in the Re-engineering Assessment Practices (REAP) project. These considerations helped motivate the authors to explore podcasts as a means of promoting sustainable assessment with fourth year undergraduates and consider their potential within professional graduate courses. The research explored the following questions: - Did the process of preparing podcasts extend their professional learning? - Can pre-service teachers deliver a well planned, coherent and well organised presentation to demonstrate their understanding of principles of learning and teaching? - Can pre-service teachers prepare a podcast to describe their own action research findings? Pre-service science teachers found the process challenging and rewarding. Pre-service teachers prepared podcast presentations that described their own action research findings. Pre-service teachers delivered well planned, coherent and well organised presentations to demonstrate their understanding of principles of learning and teaching. The process of preparing podcasts extended their professional learning in a variety of ways - base level technical competence in managing the software; pedagogically in identifying and supporting a teaching and learning resource; and professionally in relation to the Benchmark Standards for ITE. The approach is transferable to further study with a larger group of PGDE pre-service teachers

    Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C). Part 1. The Irish Sea

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    Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon (14C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14C dispersal and uptake dynamics. All east basin biota exhibited 14C enrichments above ambient background while most west basin biota had 14C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14C to the west basin and retention therein. Despite ongoing Sellafield 14C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14C-enriched organic material by organisms and mixing to depth of 14C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant

    Potential use of oxygen as a metabolic biosensor in combination with T2*-weighted MRI to define the ischemic penumbra

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    We describe a novel magnetic resonance imaging technique for detecting metabolism indirectly through changes in oxyhemoglobin:deoxyhemoglobin ratios and T2* signal change during ‘oxygen challenge’ (OC, 5 mins 100% O2). During OC, T2* increase reflects O2 binding to deoxyhemoglobin, which is formed when metabolizing tissues take up oxygen. Here OC has been applied to identify tissue metabolism within the ischemic brain. Permanent middle cerebral artery occlusion was induced in rats. In series 1 scanning (n=5), diffusion-weighted imaging (DWI) was performed, followed by echo-planar T2* acquired during OC and perfusion-weighted imaging (PWI, arterial spin labeling). Oxygen challenge induced a T2* signal increase of 1.8%, 3.7%, and 0.24% in the contralateral cortex, ipsilateral cortex within the PWI/DWI mismatch zone, and ischemic core, respectively. T2* and apparent diffusion coefficient (ADC) map coregistration revealed that the T2* signal increase extended into the ADC lesion (3.4%). In series 2 (n=5), FLASH T2* and ADC maps coregistered with histology revealed a T2* signal increase of 4.9% in the histologically defined border zone (55% normal neuronal morphology, located within the ADC lesion boundary) compared with a 0.7% increase in the cortical ischemic core (92% neuronal ischemic cell change, core ADC lesion). Oxygen challenge has potential clinical utility and, by distinguishing metabolically active and inactive tissues within hypoperfused regions, could provide a more precise assessment of penumbra

    Experimental investigation of wave propagation in three dimensions in unbounded particulate assemblies

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    Understanding wave propagation through soils is essential for site response analysis in earthquake engineering, interpretation of geophysical surveys and SASW (Spectral Analysis of Surface Waves), interpretation of laboratory bender element tests, etc. Analysis of wave propagation has largely been based on continuum descriptions and two dimensional analyses. This study presents recent developments in multiaxial testing that permit the combination of laboratory seismic testing with exploration of three-dimensional principal stress space. A Cubical Cell Apparatus with bender-extender piezoceramic elements fitted in all six faces are used so that wave propagation velocities of an analogue granular material can be determined. The results of a first series of wave propagation tests for a sample under isotropic confinement are presented

    Regeneration and poverty: evidence and policy review. Final report

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    First paragraph: This review assesses the impact of regeneration on poverty. It is one of a series of evidence reviews produced for the Joseph Rowntree Foundation (JRF) as part of a programme of work to develop an anti-poverty strategy for the UK

    Five-year review of absconding in three acute psychiatric inpatient wards in Australia

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    Author accepted manuscript (Post-Print) made available in accordance with publisher copyright policy. Under 12 month embargo, available from 2 February 2016

    Extent of hypoattenuation on CT angiography source images in Basilar Artery occlusion: prognostic value in the Basilar Artery International Cooperation Study

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    <p><b>Background and Purpose:</b> The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) quantifies the extent of early ischemic changes in the posterior circulation with a 10-point grading system. We hypothesized that pc-ASPECTS applied to CT angiography source images predicts functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS).</p> <p><b>Methods:</b> BASICS was a prospective, observational registry of consecutive patients with acute symptomatic basilar artery occlusion. Functional outcome was assessed at 1 month. We applied pc-ASPECTS to CT angiography source images of patients with CT angiography for confirmation of basilar artery occlusion. We calculated unadjusted and adjusted risk ratios (RRs) of pc-ASPECTS dichotomized at ≥8 versus <8. Primary outcome measure was favorable outcome (modified Rankin Scale scores 0–3). Secondary outcome measures were mortality and functional independence (modified Rankin Scale scores 0–2).</p> <p><b>Results:</b> Of 158 patients included, 78 patients had a CT angiography source images pc-ASPECTS ≥8. Patients with a pc-ASPECTS ≥8 more often had a favorable outcome than patients with a pc-ASPECTS <8 (crude RR, 1.7; 95% CI, 0.98–3.0). After adjustment for age, baseline National Institutes of Health Stroke Scale score, and thrombolysis, pc-ASPECTS ≥8 was not related to favorable outcome (RR, 1.3; 95% CI, 0.8–2.2), but it was related to reduced mortality (RR, 0.7; 95% CI, 0.5–0.98) and functional independence (RR, 2.0; 95% CI, 1.1–3.8). In post hoc analysis, pc-ASPECTS dichotomized at ≥6 versus <6 predicted a favorable outcome (adjusted RR, 3.1; 95% CI, 1.2–7.5).</p> <p><b>Conclusions:</b> pc-ASPECTS on CT angiography source images independently predicted death and functional independence at 1 month in the CT angiography subgroup of patients in the BASICS registry.</p&gt

    Construction of simplified design <i>p-y</i> curves for liquefied soils

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    In practice, laterally loaded piles are most often modelled using a ‘Beam-on-Nonlinear-Winkler-Foundation’ (BNWF) approach. While well calibrated p-y curves exist for non-liquefied soils (e.g. soft clay and sands), the profession still lacks reliable p-y curves for liquefied soils. In fact, the latter should be consistent with the observed strain-hardening behaviour exhibited by liquefied samples in both element and physical model tests. It is recognised that this unusual strain-hardening behaviour is induced by the tendency of the liquefied soil to dilate upon undrained shearing, which ultimately results in a gradual decrease of excess pore pressure and consequent increase in stiffness and strength. The aim of this paper is twofold. First it proposes an easy-to-use empirical model for constructing stress-strain relationships for liquefied soils. This only requires three soil parameters which can be conveniently determined by means of laboratory tests, such as a cyclic triaxial and cyclic simple shear tests. Secondly, a method is illustrated for the construction of p-y curves for liquefiable soils from the proposed stress-strain model. This involves scaling of stress and strain into compatible soil reaction p and pile deflection y, respectively. The scaling factors for stress and strain axis are computed following an energy-based approach, analogous to the upper-bound method used in classical plasticity theory. Finally, a series of results from centrifuge tests are presented, whereby p-y curves are back-calculated from available experimental data and qualitatively compared with that proposed by the authors
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