A well-scaling natural orbital theory

We introduce an energy functional for ground-state electronic structure calculations. Its variables are the natural spin-orbitals of singlet many-body wave functions and their joint occupation probabilities deriving from controlled approximations to the two-particle density matrix that yield algebraic scaling in general, and Hartree-Fock scaling in its seniority-zero version. Results from the latter version for small molecular systems are compared with those of highly accurate quantum-chemical computations. The energies lie above full configuration interaction calculations, close to doubly occupied configuration interaction calculations. Their accuracy is considerably greater than that obtained from current density-functional theory approximations and from current functionals of the one-particle density matrix.Comment: http://www.pnas.org/cgi/doi/10.1073/pnas.1615729113. arXiv admin note: text overlap with arXiv:1309.392

Assessing patients' experience of integrated care: a survey of patient views in the North West London Integrated Care Pilot

Despite the importance of continuity of care and patient engagement, few studies have captured patients' views on integrated care. This study assesses patient experience in the Integrated Care Pilot in North West London with the aim to help clinicians and policymakers understand patients' acceptability of integrated care and design future initiatives

Ponašanje materijala X5CrNiMo 17-12-2 tijekom procesa dubokog vučenja

The subject of this paper is investigation of steel X5CrNiMo 17-12-2 in a deep drawing process. Material and mechanical properties are investigated in order to obtain a number of parameters that are needed for the deep drawing process. Tolerances for final product dimensions were taken and a procedure for deep drawing process was calculated. Tooling was modelled with Solidworks software. Experiments were performed in order to determine functionality of tooling, feasibility and influential factors on process uncertainties.Istraživana su materijalna i mehanička svojstva kako bi se saznalo niz parametara potrebnih u procesu dubokog vučenja. Uzete su tolerancije konačnih dimenzija proizvoda te je prema njima izračunat proces duboko vučenje. Modelirani su alati u računalnom programu Solidworks. Provedeni su eksperimenti kako bi se odredila funkcionalnost alata, sposobnost izrade gotovog proizvoda, te odredilo faktore koji utječu na nesigurnost postupka

Multidisciplinary group performance—measuring integration intensity in the context of the North West London Integrated Care Pilot

Introduction: Multidisciplinary Group meetings (MDGs) are seen as key facilitators of integration, moving from individual to multidisciplinary decision-making, and from a focus on individual patients to a focus on patient groups. We have developed a method for coding MDG transcripts to identify whether they are or are not vehicles for delivering the anticipated efficiency improvements across various providers and apply it to a test case in the North West London Integrated Care Pilot. Methods: We defined ‘integrating’ as the process within the MDG meeting that enables or promotes an improved collaboration, improved understanding, and improved awareness of self and others within the local healthcare economy such that efficiency improvements could be identified and action taken. Utterances within the MDGs are coded according to three distinct domains grounded in concepts from communication, group decision-making, and integrated care literatures—the Valence, the Focus, and the Level. Standardized weighted integrative intensity scores are calculated across ten time deciles in the Case Discussion providing a graphical representation of its integrative intensity. Results: Intra- and Inter-rater reliability of the coding scheme was very good as measured by the Prevalence and Bias-adjusted Kappa Score. Standardized Weighted Integrative Intensity graph mirrored closely the verbatim transcript and is a convenient representation of complex communication dynamics. Trend in integrative intensity can be calculated and the characteristics of the MDG can be pragmatically described. Conclusion: This is a novel and potentially useful method for researchers, managers and practitioners to better understand MDG dynamics and to identify whether participants are integrating. The degree to which participants use MDG meetings to develop an integrated way of working is likely to require management, leadership and shared values

Order-N implementation of exact exchange in extended systems

Exact (Hartree Fock) exchange is needed to overcome some of the limitations of local and semilocal approximations of density functional theory (DFT). So far, however, computational cost has limited the use of exact exchange in plane wave calculations for extended systems. We show that this difficulty can be overcome by performing a unitary transformation from Bloch to Maximally Localized Wannier functions in combination with an efficient technique to compute real space Coulomb integrals. The resulting scheme scales linearly with system size. We validate the scheme with representative applications.Comment: 6 pages, 3 figures, 3 table

Point defect dynamics in bcc metals

We present an analysis of the time evolution of self-interstitial atom and vacancy (point defect) populations in pure bcc metals under constant irradiation flux conditions. Mean-field rate equations are developed in parallel to a kinetic Monte Carlo (kMC) model. When only considering the elementary processes of defect production, defect migration, recombination and absorption at sinks, the kMC model and rate equations are shown to be equivalent and the time evolution of the point defect populations is analyzed using simple scaling arguments. We show that the typically large mismatch of the rates of interstitial and vacancy migration in bcc metals can lead to a vacancy population that grows as the square root of time. The vacancy cluster size distribution under both irreversible and reversible attachment can be described by a simple exponential function. We also consider the effect of highly mobile interstitial clusters and apply the model with parameters appropriate for vanadium and $\alpha-$iron.Comment: to appear in Phys. Rev.

Evaluation of complex integrated care programmes: the approach in North West London

Background: Several local attempts to introduce integrated care in the English National Health Service have been tried, with limited success. The Northwest London Integrated Care Pilot attempts to improve the quality of care of the elderly and people with diabetes by providing a novel integration process across primary, secondary and social care organisations. It involves predictive risk modelling, care planning, multidisciplinary management of complex cases and an information technology tool to support information sharing. This paper sets out the evaluation approach adopted to measure its effect. Study design: We present a mixed methods evaluation methodology. It includes a quantitative approach measuring changes in service utilization, costs, clinical outcomes and quality of care using routine primary and secondary data sources. It also contains a qualitative component, involving observations, interviews and focus groups with patients and professionals, to understand participant experiences and to understand the pilot within the national policy context. Theory and discussion: This study considers the complexity of evaluating a large, multi-organisational intervention in a changing healthcare economy. We locate the evaluation within the theory of evaluation of complex interventions. We present the specific challenges faced by evaluating an intervention of this sort, and the responses made to mitigate against them. Conclusions: We hope this broad, dynamic and responsive evaluation will allow us to clarify the contribution of the pilot, and provide a potential model for evaluation of other similar interventions. Because of the priority given to the integrated agenda by governments internationally, the need to develop and improve strong evaluation methodologies remains strikingly important

Use of smartphones for detecting diabetic retinopathy: a protocol for a scoping review of diagnostic test accuracy studies

Introduction: Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus and the leading cause of impaired vision in adults worldwide. Early detection and treatment for DR could improve patient outcomes. Traditional methods of detecting DR include the gold standard Early Treatment Diabetic Retinopathy Study (ETDRS) seven standard fields fundus photography, ophthalmoscopy and slit-lamp biomicroscopy. These modalities can be expensive, difficult to access and require involvement of specialised healthcare professionals. With the development of mobile phone technology, there is a growing interest in their use for DR identification as this approach is potentially more affordable, accessible and easier to use. Smartphones can be employed in a variety of ways for ophthalmoscopy including the use of smartphone camera, various attachments and artificial intelligence for obtaining and grading of retinal images. The aim of this scoping review is to determine the diagnostic test accuracy of various smartphone ophthalmoscopy approaches for detecting DR in diabetic patients. Methods and analysis: We will perform an electronic search of MEDLINE, Embase and Cochrane Library for literature published from 2000 onwards. Two reviewers will independently analyse studies for eligibility and assess study quality using the QUADAS-2 tool. Data for a 2⨉2 contingency table will be extracted. If possible, we will pool sensitivity and specificity data using the random-effects model and construct a summary receiver operating characteristic (SROC) curve. In case of high heterogeneity, we will present the findings narratively. Subgroup analysis and sensitivity analysis will be performed where appropriate. Ethics and dissemination: This scoping review aims to provide an overview of smartphone ophthalmoscopy in DR identification. It will present findings on the accuracy of smartphone ophthalmoscopy in detecting DR, identify gaps in the literature and provide recommendations for future research. This review does not require ethical approval as we will not collect primary data

Ab initio Molecular Dynamics in Adaptive Coordinates

We present a new formulation of ab initio molecular dynamics which exploits the efficiency of plane waves in adaptive curvilinear coordinates, and thus provides an accurate treatment of first-row elements. The method is used to perform a molecular dynamics simulation of the CO_2 molecule, and allows to reproduce detailed features of its vibrational spectrum such as the splitting of the Raman sigma+_g mode caused by Fermi resonance. This new approach opens the way to highly accurate ab initio simulations of organic compounds.Comment: 11 pages, 3 PostScript figure