Ultrahigh Energy Nuclei in the Turbulent Galactic Magnetic Field

In this work we study how the turbulent component of the Galactic magnetic field (GMF) affects the propagation of ultrahigh energy heavy nuclei. We investigate first how the images of individual sources and of the supergalactic plane depend on the properties of the turbulent GMF. Then we present a quantitative study of the impact of the turbulent field on (de-) magnification of source fluxes, due to magnetic lensing effects. We also show that it is impossible to explain the Pierre Auger data assuming that all ultrahigh energy nuclei are coming from Cen A, even in the most favorable case of a strong, extended turbulent field in the Galactic halo.Comment: 10 pages (2 columns), 8 figures. Published in Astroparticle Physic

Trust, regulatory processes and NICE decision-making: Appraising cost-effectiveness models through appraising people and systems.

This article presents an ethnographic study of regulatory decision-making regarding the cost-effectiveness of expensive medicines at the National Institute for Health and Care Excellence (NICE) in England. We explored trust as one important mechanism by which problems of complexity and uncertainty were resolved. Existing studies note the salience of trust for regulatory decisions, by which the appraisal of people becomes a proxy for appraising technologies themselves. Although such (dis)trust in manufacturers was one important influence, we describe a more intricate web of (dis)trust relations also involving various expert advisors, fellow committee members and committee Chairs. Within these complex chains of relations, we found examples of both more blind-acquiescent and more critical-investigative forms of trust as well as, at times, pronounced distrust. Difficulties in overcoming uncertainty through other means obliged trust in some contexts, although not in others. (Dis)trust was constructed through inferences involving abstract systems alongside actors’ oral and written presentations-of-self. Systemic features and ‘forced options’ to trust indicate potential insidious processes of regulatory capture

Poisson Cluster Process Models for Detecting Ultra-Diffuse Galaxies

We propose a novel set of Poisson Cluster Process (PCP) models to detect Ultra-Diffuse Galaxies (UDGs), a class of extremely faint, enigmatic galaxies of substantial interest in modern astrophysics. We model the unobserved UDG locations as parent points in a PCP, and infer their positions based on the observed spatial point patterns of their old star cluster systems. Many UDGs have somewhere from a few to hundreds of these old star clusters, which we treat as offspring points in our models. We also present a new framework to construct a marked PCP model using the marks of star clusters. The marked PCP model may enhance the detection of UDGs and offers broad applicability to problems in other disciplines. To assess the overall model performance, we design an innovative assessment tool for spatial prediction problems where only point-referenced ground truth is available, overcoming the limitation of standard ROC analyses where spatial Boolean reference maps are required. We construct a bespoke blocked Gibbs adaptive spatial birth-death-move MCMC algorithm to infer the locations of UDGs using real data from a \textit{Hubble Space Telescope} imaging survey. Based on our performance assessment tool, our novel models significantly outperform existing approaches using the Log-Gaussian Cox Process. We also obtained preliminary evidence that the marked PCP model improves UDG detection performance compared to the model without marks. Furthermore, we find evidence of a potential new ``dark galaxy'' that was not detected by previous methods.Comment: 47 pages, 8 figures, 3 tables; submitted to AoAS, comments are welcom

Degenerate Domain Wall Solutions in Supersymmetric Theories

A family of degenerate domain wall configurations, partially preserving supersymmetry, is discussed in a generalized Wess-Zumino model with two scalar superfields. We establish some general features inherent to the models with continuously degenerate domain walls. For instance, for purely real trajectories additional "integrals of motion" exist. The solution for the profile of the scalar fields for any wall belonging to the family is found in quadratures for arbitrary ratio of the coupling constants. For a special value of this ratio the solution family is obtained explicitly in terms of elementary functions. We also discuss the threshold amplitudes for multiparticle production generated by these solutions. New unexpected nullifications of the threshold amplitudes are found.Comment: 21 pages, LaTeX, 3 figures using epsf.st

The peripheral blood transcriptome in septic cardiomyopathy: an observational, pilot study.

BACKGROUND:Septic cardiomyopathy (SCM) is common in sepsis and associated with increased morbidity and mortality. Left ventricular global longitudinal strain (LV GLS), measured by speckle tracking echocardiography, allows improved identification of impaired cardiac contractility. The peripheral blood transcriptome may be an important window into SCM pathophysiology. We therefore studied the peripheral blood transcriptome and LV GLS in a prospective cohort of patients with sepsis. RESULTS:In this single-center observational pilot study, we enrolled adult patients (age > 18) with sepsis within 48 h of admission to the ICU. SCM was defined as LV GLS > - 17% based on echocardiograms performed within 72 h of admission. We enrolled 27 patients, 24 of whom had high-quality RNA results; 18 (75%) of 24 had SCM. The group was 50% female and had a median (IQR) age of 59.5 (48.5-67.0) years and admission APACHE II score of 21.0 (16.0-32.3). Forty-six percent had septic shock. After filtering for low-expression and non-coding genes, 15,418 protein coding genes were expressed and 73 had significantly different expression between patients with vs. without SCM. In patients with SCM, 43 genes were upregulated and 30 were downregulated. Pathway analysis identified enrichment in type 1 interferon signaling (adjusted p < 10-5). CONCLUSIONS:In this hypothesis-generating study, SCM was associated with upregulation of genes in the type 1 interferon signaling pathway. Interferons are cytokines that stimulate the innate and adaptive immune response and are implicated in the early proinflammatory and delayed immunosuppression phases of sepsis. While type 1 interferons have not been implicated previously in SCM, interferon therapy (for viral hepatitis and Kaposi sarcoma) has been associated with reversible cardiomyopathy, perhaps suggesting a role for interferon signaling in SCM

A spatially-VSL gravity model with 1-PN limit of GRT

A scalar gravity model is developed according the 'geometric conventionalist' approach introduced by Poincare (Einstein 1921, Poincare 1905, Reichenbach 1957, Gruenbaum1973). In principle this approach allows an alternative interpretation and formulation of General Relativity Theory (GRT), with distinct i) physical congruence standard, and ii) gravitation dynamics according Hamilton-Lagrange mechanics, while iii) retaining empirical indistinguishability with GRT. In this scalar model the congruence standards have been expressed as gravitationally modified Lorentz Transformations (Broekaert 2002). The first type of these transformations relate quantities observed by gravitationally 'affected' (natural geometry) and 'unaffected' (coordinate geometry) observers and explicitly reveal a spatially variable speed of light (VSL). The second type shunts the unaffected perspective and relates affected observers, recovering i) the invariance of the locally observed velocity of light, and ii) the local Minkowski metric (Broekaert 2003). In the case of a static gravitation field the model retrieves the phenomenology implied by the Schwarzschild metric. The case with proper source kinematics is now described by introduction of a 'sweep velocity' field w: The model then provides a hamiltonian description for particles and photons in full accordance with the first Post-Newtonian approximation of GRT (Weinberg 1972, Will 1993).Comment: v1: 11 pages, GR17 conf. paper, Dublin 2004, v2: WEP issue solved, section on acceleration transformation added, text improved, more references, same results, v3: typos removed, footnotes, added and references updated, v4: appendix added, improved tex

Healthcare IT Adoption under Different Government Models: Debating the HITECH Impacts

Governments around the world are investing in healthcare as they attempt to increase access to care and the quality of care, while simultaneously lowering the costs of providing care. Many of these investments are in healthcare IT (HIT). The IT software industry is preparing for intensive competition for their HIT packages and workers in response to government and private industry investments. Yet different national healthcare models have produced widely differing healthcare outcomes and HIT adoption rates, with the U.S. performing poorly on both. The objective of this panel is to provide insights based on HIT research conducted in multiple healthcare contexts under different national government models, and then to engage the panel audience in debating the prospects for success of three IT-enabled healthcare delivery reforms being government-funded in the U.S. over the next 5 years. Our larger goal is to provide a forum for information sharing that will motivate other IS researchers across the global IS research community to contribute to the design of solutions and the capturing of best practices that will address some of the key goals of IT-enabled healthcare reform: improved access and quality, and decreased costs

Tackling Exascale Software Challenges in Molecular Dynamics Simulations with GROMACS

GROMACS is a widely used package for biomolecular simulation, and over the last two decades it has evolved from small-scale efficiency to advanced heterogeneous acceleration and multi-level parallelism targeting some of the largest supercomputers in the world. Here, we describe some of the ways we have been able to realize this through the use of parallelization on all levels, combined with a constant focus on absolute performance. Release 4.6 of GROMACS uses SIMD acceleration on a wide range of architectures, GPU offloading acceleration, and both OpenMP and MPI parallelism within and between nodes, respectively. The recent work on acceleration made it necessary to revisit the fundamental algorithms of molecular simulation, including the concept of neighborsearching, and we discuss the present and future challenges we see for exascale simulation - in particular a very fine-grained task parallelism. We also discuss the software management, code peer review and continuous integration testing required for a project of this complexity.Comment: EASC 2014 conference proceedin

py4DSTEM: a software package for multimodal analysis of four-dimensional scanning transmission electron microscopy datasets

Scanning transmission electron microscopy (STEM) allows for imaging, diffraction, and spectroscopy of materials on length scales ranging from microns to atoms. By using a high-speed, direct electron detector, it is now possible to record a full 2D image of the diffracted electron beam at each probe position, typically a 2D grid of probe positions. These 4D-STEM datasets are rich in information, including signatures of the local structure, orientation, deformation, electromagnetic fields and other sample-dependent properties. However, extracting this information requires complex analysis pipelines, from data wrangling to calibration to analysis to visualization, all while maintaining robustness against imaging distortions and artifacts. In this paper, we present py4DSTEM, an analysis toolkit for measuring material properties from 4D-STEM datasets, written in the Python language and released with an open source license. We describe the algorithmic steps for dataset calibration and various 4D-STEM property measurements in detail, and present results from several experimental datasets. We have also implemented a simple and universal file format appropriate for electron microscopy data in py4DSTEM, which uses the open source HDF5 standard. We hope this tool will benefit the research community, helps to move the developing standards for data and computational methods in electron microscopy, and invite the community to contribute to this ongoing, fully open-source project