UBVRI twilight sky brightness at ESO-Paranal

Twilight studies have proved to be important tools to analyze the atmospheric structure with interesting consequences on the characterization of astronomical sites. Active discussions on this topic have been recently restarted in connection with the evaluation of Dome C, Antarctica as a potential astronomical site and several site-testing experiments, including twilight brightness measurements, are being prepared. The present work provides for the first time absolute photometric measurements of twilight sky brightness for ESO-Paranal (Chile), which are meant both as a contribution to the site monitoring and as reference values in the analysis of other sites, including Dome C. The UBVRI twilight sky brightness was estimated on more than 2000 FORS1 archival images, which include both flats and standard stars observations taken in twilight, covering a Sun zenith distance range 94-112 deg. The comparison with a low altitude site shows that Paranal V twilight sky brightness is about 30% lower, implying that some fraction of multiple scattering has to take place at an altitude of a few km above the sea level.Comment: 11 pages, 13 figures, accepted for publication in A&

Incidence and evaluation of incidental abnormal bone marrow signal on magnetic resonance imaging.

PurposeThe increased use of magnetic resonance imaging (MRI) has resulted in reports of incidental abnormal bone marrow (BM) signal. Our goal was to determine the evaluation of an incidental abnormal BM signal on MRI and the prevalence of a subsequent oncologic diagnosis.MethodsWe conducted a retrospective cohort study of patients over age 18 undergoing MRI between May 2005 and October 2010 at Tufts Medical Center (TMC) with follow-up through November 2013. The electronic medical record was queried to determine imaging site, reason for scan, evaluation following radiology report, and final diagnosis.Results49,678 MRIs were done with 110 patients meeting inclusion criteria. Twenty two percent underwent some evaluation, most commonly a complete blood count, serum protein electrophoresis, or bone scan. With median follow-up of 41 months, 6% of patients were diagnosed with malignancies including multiple myeloma, non-Hodgkins lymphoma, metastatic non-small cell lung cancer, and metastatic adenocarcinoma. One patient who had not undergone evaluation developed breast cancer 24 months after the MRI.ConclusionsIncidentally noted abnormal or heterogeneous bone marrow signal on MRI was not inconsequential and should prompt further evaluation

Postpartum Safety and Satisfaction Following Early Discharge

Two Ontario sites were involved in the evaluation of an obstetrical discharge program. Before program implementation a group of eligible women were enrolled as the preprogram control group (n = 542). During the program, eligible women who agreed to early discharge (ED) became the ED group (n = 319), and those opting not to go home early but consenting to participate in the evaluation became the concurrent group (n = 456). All groups were mailed a self-administered postpartum questionnaire. On demographic characteristics, safety and satisfaction, the ED group was comparable to the concurrent group. Hospital readmission rates did not differ across groups after stratification by site or hospital. Multiple classification analyses revealed a similar pattern for overall satisfaction levels. This unique ED program, which allowed pre- or postnatal enrollment and did not require an initial home assessment, appears to be a safe, effective and flexible approach to obstetrical care

Was There a Riverside Miracle? A Framework for Evaluating Multi-Site Programs

This paper uses data from the Greater Avenues for Independence (GAIN) initiative to discuss the evaluation of programs that are implemented at multiple sites. Two frequently used methods are to pool the data or to use fixed effects (an extreme version of which estimates separate models for each site). The former approach, however, ignores site effects. Though the latter estimates site effects, it lacks a framework for predicting the impact in subsequent implementations of the program (e.g., will a new implementation resemble Riverside or Alameda?). I develop a model for earnings that lies between these two extremes. For the GAIN data, I show that most of the differences across sites are due to differences in the composition of participants. I show also that uncertainty regarding predicting site effects is important; when the predictive uncertainty is ignored, the treatment impact for the Riverside sites is significant, but when we consider predictive uncertainty, the impact for the Riverside sites is insignificant. Finally, I demonstrate that the model is able to extrapolate site effects with reasonable accuracy, when the site for which the prediction is being made does not differ substantially from the sites already observed. For example, the San Diego treatment effects could have been predicted based on observable site characteristics, but the Riverside effects are consistently underestimated.

Addressing decisions about new hospitals’ siting: a multidimensional evaluation approach

Background. Site selection for urban facilities is a crucial topic in planning decision processes for the several side effects they produce and the multiple criteria involved, especially for healthcare facilities. Nevertheless, the location problem has been ignored by most of the existing evaluation systems. Methods. Starting from a deep literature review and the analysis of hospitals in 10 European cities, the paper proposes an evaluation system divided into four macro-areas (Functional quality, Location quality, Environmental quality, Economical aspects), each in turn composed by criteria and sub-criteria. Results. The evaluation system has been applied for the site selection of “La Città della alute” in Milan, Italy. Furthermore, the ShOS (Selection hospitals’ Site) Evaluation Tool has been defined, with the aim of assessing the land suitability for new healthcare structures. Conclusion. The ShOS evaluation tool improves the transparency and robustness of the decision-making process and it could be broadly applied

Looking For Shadows: Evaluating Community Change in the Annie E. Casey Foundation Plain Talk Initiative

This case study explores the evaluation of a large multi-city initiative that sought to make contraceptives available to sexually active youth to reduce pregnancy and sexually-transmitted diseases. The evaluation design included within-site and cross-site analysis and featured multiple data collection strategies, including a baseline and follow-up survey, a heavy emphasis on qualitative research, and review of administrative data. This case explores the challenges of evaluating a politically charged initiative, with many expectations on the part of many stakeholders

A mask-based approach for the geometric calibration of thermal-infrared cameras

Accurate and efficient thermal-infrared (IR) camera calibration is important for advancing computer vision research within the thermal modality. This paper presents an approach for geometrically calibrating individual and multiple cameras in both the thermal and visible modalities. The proposed technique can be used to correct for lens distortion and to simultaneously reference both visible and thermal-IR cameras to a single coordinate frame. The most popular existing approach for the geometric calibration of thermal cameras uses a printed chessboard heated by a flood lamp and is comparatively inaccurate and difficult to execute. Additionally, software toolkits provided for calibration either are unsuitable for this task or require substantial manual intervention. A new geometric mask with high thermal contrast and not requiring a flood lamp is presented as an alternative calibration pattern. Calibration points on the pattern are then accurately located using a clustering-based algorithm which utilizes the maximally stable extremal region detector. This algorithm is integrated into an automatic end-to-end system for calibrating single or multiple cameras. The evaluation shows that using the proposed mask achieves a mean reprojection error up to 78% lower than that using a heated chessboard. The effectiveness of the approach is further demonstrated by using it to calibrate two multiple-camera multiple-modality setups. Source code and binaries for the developed software are provided on the project Web site

kmos: A lattice kinetic Monte Carlo framework

Kinetic Monte Carlo (kMC) simulations have emerged as a key tool for microkinetic modeling in heterogeneous catalysis and other materials applications. Systems, where site-specificity of all elementary reactions allows a mapping onto a lattice of discrete active sites, can be addressed within the particularly efficient lattice kMC approach. To this end we describe the versatile kmos software package, which offers a most user-friendly implementation, execution, and evaluation of lattice kMC models of arbitrary complexity in one- to three-dimensional lattice systems, involving multiple active sites in periodic or aperiodic arrangements, as well as site-resolved pairwise and higher-order lateral interactions. Conceptually, kmos achieves a maximum runtime performance which is essentially independent of lattice size by generating code for the efficiency-determining local update of available events that is optimized for a defined kMC model. For this model definition and the control of all runtime and evaluation aspects kmos offers a high-level application programming interface. Usage proceeds interactively, via scripts, or a graphical user interface, which visualizes the model geometry, the lattice occupations and rates of selected elementary reactions, while allowing on-the-fly changes of simulation parameters. We demonstrate the performance and scaling of kmos with the application to kMC models for surface catalytic processes, where for given operation conditions (temperature and partial pressures of all reactants) central simulation outcomes are catalytic activity and selectivities, surface composition, and mechanistic insight into the occurrence of individual elementary processes in the reaction network.Comment: 21 pages, 12 figure