A realistic evaluation : the case of protocol-based care

Background 'Protocol based care' was envisioned by policy makers as a mechanism for delivering on the service improvement agenda in England. Realistic evaluation is an increasingly popular approach, but few published examples exist, particularly in implementation research. To fill this gap, within this paper we describe the application of a realistic evaluation approach to the study of protocol-based care, whilst sharing findings of relevance about standardising care through the use of protocols, guidelines, and pathways. Methods Situated between positivism and relativism, realistic evaluation is concerned with the identification of underlying causal mechanisms, how they work, and under what conditions. Fundamentally it focuses attention on finding out what works, for whom, how, and in what circumstances. Results In this research, we were interested in understanding the relationships between the type and nature of particular approaches to protocol-based care (mechanisms), within different clinical settings (context), and what impacts this resulted in (outcomes). An evidence review using the principles of realist synthesis resulted in a number of propositions, i.e., context, mechanism, and outcome threads (CMOs). These propositions were then 'tested' through multiple case studies, using multiple methods including non-participant observation, interviews, and document analysis through an iterative analysis process. The initial propositions (conjectured CMOs) only partially corresponded to the findings that emerged during analysis. From the iterative analysis process of scrutinising mechanisms, context, and outcomes we were able to draw out some theoretically generalisable features about what works, for whom, how, and what circumstances in relation to the use of standardised care approaches (refined CMOs). Conclusions As one of the first studies to apply realistic evaluation in implementation research, it was a good fit, particularly given the growing emphasis on understanding how context influences evidence-based practice. The strengths and limitations of the approach are considered, including how to operationalise it and some of the challenges. This approach provided a useful interpretive framework with which to make sense of the multiple factors that were simultaneously at play and being observed through various data sources, and for developing explanatory theory about using standardised care approaches in practice

Accurate exchange-correlation energies for the warm dense electron gas

Density matrix quantum Monte Carlo (DMQMC) is used to sample exact-on-average $N$-body density matrices for uniform electron gas systems of up to 10$^{124}$ matrix elements via a stochastic solution of the Bloch equation. The results of these calculations resolve a current debate over the accuracy of the data used to parametrize finite-temperature density functionals. Exchange-correlation energies calculated using the real-space restricted path-integral formalism and the $k$-space configuration path-integral formalism disagree by up to $\sim$$10$\% at certain reduced temperatures $T/T_F \le 0.5$ and densities $r_s \le 1$. Our calculations confirm the accuracy of the configuration path-integral Monte Carlo results available at high density and bridge the gap to lower densities, providing trustworthy data in the regime typical of planetary interiors and solids subject to laser irradiation. We demonstrate that DMQMC can calculate free energies directly and present exact free energies for $T/T_F \ge 1$ and $r_s \le 2$.Comment: Accepted version: added free energy data and restructured text. Now includes supplementary materia

The 1980 pressure response and flank failure of Mount St. Helens (USA) inferred from seismic scaling exponents

The cataclysmic 18 May 1980 eruption at Mount St. Helens was preceded by intense seismic activity marking the mechanical response of the volcanic edifice to interior pressurisation. This seismicity is analysed to yield the temporal change in the seismic scaling exponent, D, inferred from the seismic b-value, that in-turn is related to the seismic moment of an earthquake. Time evolution of D preceding the eruption onset reveals: (1) a major decrease in D occurring over only a few days at the end of March; (2) a steady but stepped decrease in D (steps ~5–10 days) occurring from the end of March to early May; (3) a sharp decrease in D in early May; and (4) steady low values of D occurring 2–3 days before the eruption onset. This response is interpreted as major ruptures, formed at the end of March, arresting and participating in, but not triggering the ultimate failure of the flank. Rather, the rate of interior fracturing slowed in the 2 months preceding the 18 May 1980 major blast, and the triggering of failure is consistent with interior gas overpressurisation. The occurrence of two swarms of low frequency seismic events and the high values of the harmonic tremor indicate the action of interior pressurisation on a cycle of 20–25 days. Solutions are applied to represent the harmonic interior pressurisation of the edifice by gas exsolving from the volcano core. The transient radial migration of overpressured gas may reduce the apparent strength of the edifice, and ultimately trigger failure of the flank. Importantly, this mechanism is capable of triggering flank failure both after multiple core pressurisation cycles have been sustained, and as core pressures are low and diminishing—and may be a minimum. These twin attributes are both apparent in the seismic record for Mount St. Helens, used as a proxy for the unrecorded timing and magnitude of gas pressurisation at the volcano core.Published155-168partially_ope

Juvenile salamander dispersal and use of terrestrial microhabitat cues

Abstract only availableThe effects of deforestation are profound on amphibian populations. In order to balance land use practices with amphibian conservation, biologists and land managers must understand the habitat requirements of amphibians at all life stages. Ambystomatid salamanders have an aquatic larval stage followed by metamorphosis and dispersal into terrestrial habitats. In our study, we were interested in understanding the olfactory cues juvenile salamanders perceive from the microhabitat surrounding their natal pond that can lead them to a moist, cool environment. In particular, we wanted to know if forest-associated salamanders receive an olfactory cue from forest leaf litter that they do not receive from grassland litter. Further, if they are getting the cue from leaf litter, is it present in both decomposing and freshly fallen leaves? We hypothesized that forest-associated salamanders would respond positively to cues in forest leaf litter, and that because decomposing leaf litter contains fungi and other decomposing organisms, it would provide a better cue than fresh leaves. To test our hypothesis, we conducted experimental choice tests with two salamander species (n=72). Each salamander was presented with two substrate options. First we tested grassland versus forest litter, followed by decomposing versus freshly fallen leaves. An individual's substrate location ,recorded at 3- minute intervals for 60 minutes determined preference. Ambystoma maculatum, a forest dependent species, showed a preference for forest leaf litter, suggesting they use an olfactory cue found in forest litter to select favorable microhabitats. The second experiment demonstrated a preference for decomposing rather than fresh leaves by both species, suggesting the cue is from forest-associated fungi and decomposers. Immediately fallowing timber harvesting, there is likely a lag period in which the substrate retains the forest olfactory cues. The result is an ecological trap for dispersing juvenile salamanders, which may select clearcuts while the litter maintains the favorable cue.NSF grant to R. Semlitsc

Mental health and wellbeing during the transition to fatherhood: A systematic review of first time fathers’ experiences

COPYRIGHT 2018 THE AUTHORS PUBLISHED BY WOLTERS KLUWER HEALTH, INC. ON BEHALF OF THE JOANNA BRIGGS INSTITUTE. Objective: The aim of this systematic review was to identify and synthesize the best available evidence on first time fathers’ experiences and needs in relation to their mental health and wellbeing during their transition to fatherhood. Introduction: Men’s mental health and wellbeing during their transition to fatherhood is an important public health issue that is currently under-researched from a qualitative perspective and poorly understood. Inclusion criteria: Resident first time fathers (biological and non-biological) of healthy babies born with no identified terminal or long-term conditions were included. The phenomena of interest were their experiences and needs in relation to mental health and wellbeing during their transition to fatherhood, from commencement of pregnancy until one year after birth. Studies based on qualitative data, including, but not limited to, designs within phenomenology, grounded theory, ethnography and action research were included. Methods: A three-step search strategy was used. The search strategy explored published and unpublished qualitative studies from 1960 to September 2017. All included studies were assessed by two independent reviewers and any disagreements were resolved by consensus or with a third reviewer. The recommended Joanna Briggs Institute (JBI) approach to critical appraisal, study selection, data extraction and data synthesis was used. Results: Twenty-two studies met the eligibility criteria and were included in the review, which were then assessed to be of moderate to high quality (scores 5-10) based on the JBI Critical Appraisal Checklist for Qualitative Research. The studies were published between 1990 and 2017, and all used qualitative methodologies to accomplish the overall aim of investigating the experiences of expectant or new fathers. Nine studies were from the UK, three from Sweden, three from Australia, two from Canada, two from the USA, one from Japan, one from Taiwan and one from Singapore. The total number of first time fathers included in the studies was 351. One hundred and forty-four findings were extracted from the included studies. Of these, 142 supported findings were aggregated into 23 categories and seven synthesized findings: 1) New fatherhood identity, 2) Competing challenges of new fatherhood, 3) Negative feelings and fears, 4) Stress and coping, 5) Lack of support, 6) What new fathers want, and 7) Positive aspects of fatherhood. Conclusions: Based on the synthesized findings, three main factors that affect first time fathers’ mental health and wellbeing during their transition to fatherhood were identified: the formation of the fatherhood identity, competing challenges of the new fatherhood role and negative feelings and fears relating to it. The role restrictions and changes in lifestyle often resulted in feelings of stress, for which fathers used denial or escape activities, such as smoking, working longer hours or listening to music, as coping techniques. Fathers wanted more guidance and support around the preparation for fatherhood, and partner relationship changes. Barriers to accessing support included lack of tailored information resources and acknowledgment from health professionals. Better preparation for fatherhood, and support for couple relationships during the transition to parenthood could facilitate better experiences for new fathers, and contribute to better adjustments and mental wellbeing in new fathers

The Antiferromagnetic Band Structure of La2CuO4 Revisited

Using the Becke-3-LYP functional, we have performed band structure calculations on the high temperature superconductor parent compound, La2CuO4. Under the restricted spin formalism (rho(alpha) equal to rho(beta)), the R-B3LYP band structure agrees well with the standard LDA band structure. It is metallic with a single Cu x2-y2/O p(sigma) band crossing the Fermi level. Under the unrestricted spin formalism (rho(alpha) not equal to rho(beta)), the UB3LYP band structure has a spin polarized antiferromagnetic solution with a band gap of 2.0 eV, agreeing well with experiment. This state is 1.0 eV (per formula unit) lower than that calculated from the R-B3LYP. The apparent high energy of the spin restricted state is attributed to an overestimate of on-site Coulomb repulsion which is corrected in the unrestricted spin calculations. The stabilization of the total energy with spin polarization arises primarily from the stabilization of the x2-y2 band, such that the character of the eigenstates at the top of the valence band in the antiferromagnetic state becomes a strong mixture of Cu x2-y2/O p(sigma) and Cu z2/O' p(z). Since the Hohenberg-Kohn theorem requires the spin restricted and spin unrestricted calculations give exactly the same ground state energy and total density for the exact functionals, this large disparity in energy reflects the inadequacy of current functionals for describing the cuprates. This calls into question the use of band structures based on current restricted spin density functionals (including LDA) as a basis for single band theories of superconductivity in these materials.Comment: 13 pages, 8 figures, to appear in Phys. Rev. B, for more information see http://www.firstprinciples.co

A Reconstruction-Classification Method for Multifrequency Electrical Impedance Tomography

Multifrequency Electrical Impedance Tomography is an imaging technique which distinguishes biological tissues by their unique conductivity spectrum. Recent results suggest that the use of spectral constraints can significantly improve image quality. We present a combined reconstruction-classification method for estimating the spectra of individual tissues, whilst simultaneously reconstructing the conductivity. The advantage of this method is that a priori knowledge of the spectra is not required to be exact in that the constraints are updated at each step of the reconstruction. In this paper, we investigate the robustness of the proposed method to errors in the initial guess of the tissue spectra, and look at the effect of introducing spatial smoothing. We formalize and validate a frequency-difference variant of reconstruction-classification, and compare the use of absolute and frequency-difference data in the case of a phantom experiment