Vista D2.1 Supporting Data for Business and Regulatory Scenarios Report

Vista examines the effects of conflicting market forces on European performance in ATM, through the evaluation of impact metrics on four key stakeholders, and the environment. The review of regulatory and business factors is presented. Vista will model the current and future (2035, 2050) framework based on the impact of regulatory and business factors. These factors are obtained from a literature review of regulations, projects and technological and operational changes. The current value of those factors and their possible evolution are captured in this deliverable

Orientational Ordering in Spatially Disordered Dipolar Systems

This letter addresses basic questions concerning ferroelectric order in positionally disordered dipolar materials. Three models distinguished by dipole vectors which have one, two or three components are studied by computer simulation. Randomly frozen and dynamically disordered media are considered. It is shown that ferroelectric order is possible in spatially random systems, but that its existence is very sensitive to the dipole vector dimensionality and the motion of the medium. A physical analysis of our results provides significant insight into the nature of ferroelectric transitions.Comment: 4 pages twocolumn LATEX style. 4 POSTSCRIPT figures available from [email protected]

Ferroelectric and Dipolar Glass Phases of Non-Crystalline Systems

In a recent letter [Phys. Rev. Lett. {\bf 75}, 2360 (1996)] we briefly discussed the existence and nature of ferroelectric order in positionally disordered dipolar materials. Here we report further results and give a complete description of our work. Simulations of randomly frozen and dynamically disordered dipolar soft spheres are used to study ferroelectric ordering in non-crystalline systems. We also give a physical interpretation of the simulation results in terms of short- and long-range interactions. Cases where the dipole moment has 1, 2, and 3 components (Ising, XY and XYZ models, respectively) are considered. It is found that the Ising model displays ferroelectric phases in frozen amorphous systems, while the XY and XYZ models form dipolar glass phases at low temperatures. In the dynamically disordered model the equations of motion are decoupled such that particle translation is completely independent of the dipolar forces. These systems spontaneously develop long-range ferroelectric order at nonzero temperature despite the absence of any fined-tuned short-range spatial correlations favoring dipolar order. Furthermore, since this is a nonequilibrium model we find that the paraelectric to ferroelectric transition depends on the particle mass. For the XY and XYZ models, the critical temperatures extrapolate to zero as the mass of the particle becomes infinite, whereas, for the Ising model the critical temperature is almost independent of mass and coincides with the ferroelectric transition found for the randomly frozen system at the same density. Thus in the infinite mass limit the results of the frozen amorphous systems are recovered.Comment: 25 pages (LATEX, no macros). 11 POSTSCRIPT figures enclosed. Submitted to Phisical Review E. Contact: [email protected]

Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework

Background: The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without xrays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine xrays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays. Methods: Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF. Results: Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied (social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors (social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays (belief about capabilities); and guideline awareness and agreements (knowledge). Conclusions: Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theorybased survey to help identify potential targets for behavioral-change strategies

Comparison of Karydakis versus midline excision for treatment of pilonidal sinus disease

Pilonidal sinus disease is associated with a high rate of recurrence and complications. The Karydakis (KAR) method, whereby an asymmetric subcutaneous flap obliterates the anal crease, has been shown to be effective in adults. The goal of this study is to assess the efficacy of the KAR procedure in the operative treatment of children with pilonidal sinus disease compared to those treated via a midline excision (ME). Sixty-eight cases of pediatric pilonidal sinus excision were reviewed over the past 10 years. Data abstracted included surgical approach, complication rate and recurrence rate. Student’s t -test or the Chi square test was used for statistical analysis, with P <0.05 being considered significant. An ME was performed in 44 patients; the KAR method was used in 24 patients. Mean age at diagnosis was 14.4±4.2 years for the ME group compared to 15.7±4.3 years for the KAR patients ( P =0.18). Mean operative time was significantly longer with the KAR method (58.7±25.6 min) compared to 46.3±18.6 for the primary ME ( P =0.04). Despite the increased operative dissection, there was no difference ( P =0.42) in early post-operative complication rates between groups (25% in the KAR group compared to 34.8% in the ME group). Initial drainage of an abscess had no significant effect upon the recurrence/complication rate in either group. Recurrence rate alone was lower in patients operated on via the KAR approach 0% versus 11.0% using the ME ( P =0.153). Recurrence and complication rates were lower for those patients with a pilonidal sinus treated by the KAR method compared to the ME, but the results did not reach significance. In conclusion, this study does show a potential benefit for children treated with the KAR method for pilonidal sinus. This study mimics the data obtained in adult patients and suggests that a larger study is likely to achieve significance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47167/1/383_2005_Article_1543.pd