2,724 research outputs found

    Adapting to the digital age: a narrative approach

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    The article adopts a narrative inquiry approach to foreground informal learning and exposes a collection of stories from tutors about how they adapted comfortably to the digital age. We were concerned that despite substantial evidence that bringing about changes in pedagogic practices can be difficult, there is a gap in convincing approaches to help in this respect. In this context, this project takes a “bottom-up” approach and synthesises several life-stories into a single persuasive narrative to support the process of adapting to digital change. The project foregrounds the small, every-day motivating moments, cultural features and environmental factors in people's diverse lives which may have contributed to their positive dispositions towards change in relation to technology enhanced learning. We expect that such narrative approaches could serve to support colleagues in other institutions to warm up to ever-changing technological advances

    Direct evidence for a piezoelectriclike effect in coherently strained SiGe/Si heterostructures

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    A hybrid acoustic spectroscopy technique has been used to demonstrate the (reversible) conversion of high frequency electric fields into longitudinal acoustic waves within a modulation-doped pseudomorphic Si/Si0.88Ge0.12/Si heterostructure. This provides compelling evidence for the existence of a piezoelectriclike coupling within such structures

    Decellularization of human donor aortic and pulmonary valved conduits using low concentration sodium dodecyl sulfate

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    The clinical use of decellularised cardiac valve allografts is increasing. Long term data will be required to determine whether they outperform conventional cryopreserved allografts. Valves decellularised using different processes may show varied long-term outcomes. It is therefore important to understand the effects of specific decellularisation technologies on the characteristics of donor heart valves. Human cryopreserved aortic and pulmonary valved conduits were decellularised using hypotonic buffer, 0.1% (w/v) SDS and nuclease digestion. The decellularised tissues were compared to cellular cryopreserved valve tissues using histology, immunohistochemistry, quantitation of total DNA, collagen and glycosaminoglycan content, in vitro cytotoxicity assays, uniaxial tensile testing and subcutaneous implantation in mice. The decellularised tissues showed no histological evidence of cells or cell remnants and over 97% DNA removal in all regions (arterial wall, muscle, leaflet and junction). The decellularised tissues retained collagen IV and von Willebrand factor staining with some loss of fibronectin, laminin and chondroitin sulphate staining. There was an absence of MHC Class I staining in decellularised pulmonary valve tissues, with only residual staining in isolated areas of decellularised aortic valve tissues. The collagen content of the tissues was not decreased following decellularisation however the glycosaminoglycan content was reduced. Only moderate changes in the maximum load to failure of the tissues were recorded post-decellularisation. The decellularised tissues were non-cytotoxic in vitro, and were biocompatible in vivo in a mouse subcutaneous implant model. The decellularisation process will now be translated into a GMP compatible process for donor cryopreserved valves with a view to future clinical use

    Assessment-schedule matching in unanchored indirect treatment comparisons of progression-free survival in cancer studies

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    Background The timing of efficacy-related clinical events recorded at scheduled study visits in clinical trials are interval censored, with the interval duration pre-determined by the study protocol. Events may happen any time during that interval but can only be detected during a planned or unplanned visit. Disease progression in oncology is a notable example where the time to an event is affected by the schedule of visits within a study. This can become a source of bias when studies with varying assessment schedules are used in unanchored comparisons using methods such as matching-adjusted indirect comparisons. Objective We illustrate assessment-time bias (ATB) in a simulation study based on data from a recent study in second-line treatment for locally advanced or metastatic urothelial carcinoma, and present a method to adjust for differences in assessment schedule when comparing progression-free survival (PFS) against a competing treatment. Methods A multi-state model for death and progression was used to generate simulated death and progression times, from which PFS times were derived. PFS data were also generated for a hypothetical comparator treatment by applying a constant hazard ratio (HR) to the baseline treatment. Simulated PFS times for the two treatments were then aligned to different assessment schedules so that progression events were only observed at set visit times, and the data were analysed to assess the bias and standard error of estimates of HRs between two treatments with and without assessment-schedule matching (ASM). Results ATB is highly affected by the rate of the event at the first assessment time; in our examples, the bias ranged from 3 to 11% as the event rate increased. The proposed method relies on individual-level data from a study and attempts to adjust the timing of progression events to the comparator’s schedule by shifting them forward or backward without altering the patients’ actual follow-up time. The method removed the bias almost completely in all scenarios without affecting the precision of estimates of comparative effectiveness. Conclusions Considering the increasing use of unanchored comparative analyses for novel cancer treatments based on single-arm studies, the proposed method offers a relatively simple means of improving the accuracy of relative benefits of treatments on progression times

    Endocrine responses to overreaching before and after 1 year of weightlifting

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    This is the publisher's version, also found at http://ehis.ebscohost.com/ehost/external?sid=c58e4c93-cdad-411e-8971-ff871436da4b%40sessionmgr14&vid=3&hid=1

    A comparative assessment of the information technology services sector in India and China

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    The purpose of this paper is to assess the nature of competition in the information technology (IT) services sector between India and China. Using primary and secondary data sources, we compare and contrast the strengths and weaknesses of the IT services sector in the two countries along the main dimensions of Porter&rsquo;s competitive advantage model. The principal findings indicate that the IT services sectors in the two countries are distinctively different, have developed along different paths and are highly complementary to each other. China has a well established hardware sector and its IT services sector focuses mostly on servicing its domestic market. India&rsquo;s IT services sector is predominantly export orientated with focus on the US and Western European markets. Contrary to popular beliefs, given the complementary characteristics of the IT services sectors in India and China, it is unlikely for the two countries to compete against each other in the near future and greater strategic co-operation between IT service providers in the two countries is a more likely outcome.<br /

    Phonon drag thermopower and weak localization

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    Previous experimental work on a two-dimensional (2D) electron gas in a Si-on-sapphire device led to the conclusion that both conductivity and phonon drag thermopower SgS^g are affected to the same relative extent by weak localization. The present paper presents further experimental and theoretical results on these transport coefficients for two very low mobility 2D electron gases in ή−\delta-doped GaAs/Gax_xAl1−x_{1-x}As quantum wells. The experiments were carried out in the temperature range 3-7K where phonon drag dominates the thermopower and, contrary to the previous work, the changes observed in the thermopower due to weak localization were found to be an order of magnitude less than those in the conductivity. A theoretical framework for phonon drag thermopower in 2D and 3D semiconductors is presented which accounts for this insensitivity of SgS^g to weak localization. It also provides transparent physical explanations of many previous experimental and theoretical results.Comment: 19 page Revtex file, 3 Postscript figur

    Economic Policy in a More Uncertain World

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    The Aspen Economic Strategy Group's Annual Policy Volume Economic Policy in a More Uncertain World marks the group's 5th anniversary and is released against a backdrop historic economic and strategic uncertainty. The book's seven chapters, each written by leading experts and edited by AESG Director Melissa S. Kearney and Deputy Director Amy Ganz, provide a deep-dive on long-term economic headwinds confronting the country, including demographic changes—declining fertility and population aging—and what a smaller worker to population ratio means in terms of slower economic growth, reduced revenue, and lower productivity growth. Additional chapters on the US immigration system and US innovation policy highlight potential solutions for countering these trends.  Another chapter explores potential adverse impacts on local labor markets from the green energy transition and highlights policies to avoid repeating painful mistakes of the past, including the response to the decline of the coal industry and rise of globalization and automation. A final chapter highlights lessons learned from the unprecedented federal aid to state and local governments during the COVID-19 pandemic
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