157 research outputs found
Variational and Diffusion Quantum Monte Carlo Calculations with the CASINO Code
We present an overview of the variational and diffusion quantum Monte Carlo methods as implemented in the CASINO program. We particularly focus on developments made in the last decade, describing state-of-the-art quantum Monte Carlo algorithms and software and discussing their strengths and their weaknesses. We review a range of recent applications of CASINO
Candida albicans colonization and dissemination from the murine gastrointestinal tract : the influence of morphology and Th17 immunity
This article is protected by copyright. All rights reserved. This work was supported by the Wellcome Trust (086558, 080088, 102705), a Wellcome Trust Strategic Award (097377) and a studentship from the University of Aberdeen. D.K. was supported by grant 5R01AI083344 from the National Institute of Allergy and Infectious Diseases and by a Voelcker Young Investigator Award from the Max and Minnie Tomerlin Voelcker Fund.Peer reviewedPublisher PD
Structure and metallicity of phase V of hydrogen
A new phase V of hydrogen was recently claimed in experiments above 325 GPa and 300 K. Due to the extremely small sample size at such record pressures the measurements were limited to Raman spectroscopy. The experimental data on increase of pressure shows decreasing Raman activity and darkening of the sample, which suggests band-gap closure and impending molecular dissociation, but no definite conclusions could be reached. Furthermore, the available data is insufficient to determine the structure of phase V, which remains unknown. Introducing saddle-point ab initio random structure searching (sp-AIRSS), we find several new structural candidates of hydrogen which could describe the observed properties of phase V. We investigate hydrogen metallisation in the proposed candidate structures, and demonstrate that smaller band gaps are associated with longer bond lengths. We conclude that phase V is a stepping stone towards metallisation
Anomalous nonadditive dispersion interactions in systems of three one-dimensional wires
10 pages, 8 figures, 1 tableFinancial support was provided by the U. K. Engineering and Physical Sciences Research Council (EPSRC). Part of the computations have been performed using the K computer at Advanced Institute for Computational Science, RIKEN. R.M. is grateful for financial support from KAKENHI Grants No. 23104714, No. 22104011, and No. 25600156, and from the Tokuyama Science Foundation
A “Learning Revolution”? Investigating Pedagogic Practices around Interactive Whiteboards in British Primary Classrooms
Interactive whiteboards have been rapidly introduced into all primary schools under UK Government initiatives. These large, touch-sensitive screens, which control a computer connected to a digital projector, seem to be the first type of educational technology particularly suited for whole-class teaching and learning. Strong claims are made for their value by manufacturers and policy makers, but there has been little research on how, if at all, they influence established pedagogic practices, communicative processes and educational goals. This study has been designed to examine this issue, using observations in primary (elementary) school classrooms. It is funded by the UK Economic and Social Research Council and builds on the authors’ previous research on ICT in educational dialogues and collaborative activities
Optoelectronic properties of atomically thin ReSSe with weak interlayer coupling
Rhenium dichalcogenides, such as ReS2 and ReSe2, have attracted a lot of interests due to the weak interlayered coupling in these materials. Studies of rhenium based dichalcogenide alloys will help us understand the differences between binary rhenium dichalcogenides. They will also extend the applications of two-dimensional (2D) materials through alloying. In this work, we studied the optoelectronic properties of ReSSe with a S and Se ratio of 1 : 1. The band gap of the ReSSe alloy is investigated by optical absorption spectra as well as theoretical calculations. The alloy shows weak interlayered coupling, as evidenced by the Raman spectrum. A field-effect transistor based on ReSSe shows typical n-type behavior with a mobility of about 3 cm2 V-1 s-1 and an on/off ratio of 105, together with the in-plane anisotropic conductivity. The device also shows good photoresponse properties, with a photoresponsivity of 8 A W-1. The results demonstrated here will provide new avenues for the study of 2D materials with weak interlayer interactions and in-plane anisotropy
Novel insights into host-fungal pathogen interactions derived from live-cell imaging
Acknowledgments The authors acknowledge funding from the Wellcome Trust (080088, 086827, 075470 and 099215) including a Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377 and FP7-2007–2013 grant agreement HEALTH-F2-2010-260338–ALLFUN to NARG.Peer reviewedPublisher PD
Potential benefits of using a toolkit developed to aid in the adaptation of HTA reports: a case study considering positron emission tomography (PET) and Hodgkin's disease
<p>Abstract</p> <p>Background</p> <p>The preparation of HTA reports requires a great deal of time, effort and resource, and there is a desire to improve efficiency, avoid duplication of effort and facilitate the transfer of knowledge between countries. This is of particular importance for countries with more limited resources which have less capacity to produce their own reports. The aim of this study was to investigate the extent of duplication of published Health Technology Assessment (HTA) reports, on the same technology, for the same indication; using positron emission tomography (PET) for lung cancer and Hodgkin's disease as a case study. This was done in order to assess the potential usefulness of a toolkit developed to aid in the adaptation of HTA reports from one context or country to another.</p> <p>Methods</p> <p>A systematic search of the National Institute for Health Research (NIHR) CRD HTA database was conducted in June 2008 in order to identify full HTA reports containing information on the use of PET for lung cancer and Hodgkin's disease, written in English, and readily available on the web. The contents of the reports identified were then examined to assess the extent of duplication of content between reports and potential for the use of the toolkit.</p> <p>Results</p> <p>From 132 records of HTA reports about PET, 8 reports were identified as fulfilling all the criteria set, and therefore demonstrating potential duplication of effort. All these reports covered four similar domains, technology use, safety, effectiveness and economic evaluation. Five of the reports also considered organisational aspects.</p> <p>Conclusions</p> <p>There was some duplication of effort in the preparation of HTA reports concerned with the use of PET for lung cancer and Hodgkin's disease. This is an example of where resource could have been conserved and time saved by the use of a toolkit developed to aid in the adaptation of HTA reports from one context to another.</p
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