Chirped optical X-shaped pulses in material media

In this paper we analyze the properties of chirped optical X-shaped pulses propagating in material media without boundaries. We show that such ("superluminal") pulses may recover their transverse and longitudinal shape after some propagation distance, while the ordinary chirped gaussian-pulses can recover their longitudinal shape only (since gaussian pulses suffer a progressive spreading during their propagation). We therefore propose the use of chirped optical X-type pulses to overcome the problems of both dispersion and diffraction during the pulse propagation.Comment: Replaced with a much larger and deepened version (the number of pages going on from 4 to 24; plus 4 Figures added

New localized Superluminal solutions to the wave equations with finite total energies and arbitrary frequencies

By a generalized bidirectional decomposition method, we obtain many new Superluminal localized solutions to the wave equation (for the electromagnetic case, in particular) which are suitable for arbitrary frequency bands; various of them being endowed with finite total energy. We construct, among the others, an infinite family of generalizations of the so-called "X-shaped" waves. [PACS nos.: 03.50.De; 41.20;Jb; 83.50.Vr; 62.30.+d; 43.60.+d; 91.30.Fn; 04.30.Nk; 42.25.Bs; 46.40.Cd; 52.35.Lv. Keywords: Wave equations; Wave propagation; Localized beams; Superluminal waves; Bidirectional decomposition; Bessel beams; X-shaped waves; Microwaves; Optics; Special relativity; Acoustics; Seismology; Mechanical waves; Elastic waves; Gravitational waves; Elementary particle physics].Comment: plain LaTeX file (29 pages), plus 11 figures. Replaced with addition of the FIGURES that were lacking (or poor) in the previous submissions. In press in Europ. Phys. Journal-

On the Localized superluminal Solutions to the Maxwell Equations

In the first part of this article the various experimental sectors of physics in which Superluminal motions seem to appear are briefly mentioned, after a sketchy theoretical introduction. In particular, a panoramic view is presented of the experiments with evanescent waves (and/or tunneling photons), and with the "Localized superluminal Solutions" (SLS) to the wave equation, like the so-called X-shaped waves. In the second part of this paper we present a series of new SLSs to the Maxwell equations, suitable for arbitrary frequencies and arbitrary bandwidths: some of them being endowed with finite total energy. Among the others, we set forth an infinite family of generalizations of the classic X-shaped wave; and show how to deal with the case of a dispersive medium. Results of this kind may find application in other fields in which an essential role is played by a wave-equation (like acoustics, seismology, geophysics, gravitation, elementary particle physics, etc.). This e-print, in large part a review, was prepared for the special issue on "Nontraditional Forms of Light" of the IEEE JSTQE (2003); and a preliminary version of it appeared as Report NSF-ITP-02-93 (KITP, UCSB; 2002). Further material can be found in the recent e-prints arXiv:0708.1655v2 [physics.gen-ph] and arXiv:0708.1209v1 [physics.gen-ph]. The case of the very interesting (and more orthodox, in a sense) subluminal Localized Waves, solutions to the wave equations, will be dealt with in a coming paper. [Keywords: Wave equation; Wave propagation; Localized solutions to Maxwell equations; Superluminal waves; Bessel beams; Limited-dispersion beams; Electromagnetic wavelets; X-shaped waves; Finite-energy beams; Optics; Electromagnetism; Microwaves; Special relativity]Comment: LaTeX paper of 37 pages, with 20 Figures in jpg [to be processed by PDFlatex

Proof of patient information: Analysis of 201 judicial decisions

INTRODUCTION: The ruling by the French Court of Cassation dated February 25, 1997 obliged doctors to provide proof of the information given to patients, reversing more than half a century of case law. In October 1997, it was specified that such evidence could be provided by "all means", including presumption. No hierarchy in respect of means of proof has been defined by case law or legislation. The present study analyzed judicial decisions with a view to determining the means of proof liable to carry the most weight in a suit for failure to provide due patient information. MATERIAL AND METHOD: A retrospective qualitative study was conducted for the period from January 2010 to December 2015, by a search on the LexisNexis JurisClasseur website. Two hundred and one judicial decisions relating to failure to provide due patient information were selected and analyzed to study the characteristics of the practitioners involved, the content of the information at issue and the means of proof provided. The resulting cohort of practitioners was compared with the medical demographic atlas of the French Order of Medicine, considered as exhaustive. RESULTS: Two hundred and one practitioners were investigated for failure to provide information: 45 medical practitioners (22±3%), and 156 surgeons (78±3%) including 45 orthopedic surgeons (29±3.6% of surgeons). Hundred and ninety-three were private sector (96±1.3%) and 8 public sector (4±1.3%). Hundred and one surgeons (65±3.8% of surgeons), and 26 medical practitioners (58±7.4%) were convicted. Twenty-five of the 45 orthopedic surgeons were convicted (55±7.5%). There was no significant difference in conviction rates between surgeons and medical practitioners: odds ratio, 1.339916; 95% CI [0.6393982; 2.7753764] (Chi test: p=0.49). Ninety-two practitioners based their defense on a single means of proof, and 74 of these were convicted (80±4.2%). Forty practitioners based their defense on several means of proof, and 16 of these were convicted (40±7.8%). There was a significant difference in conviction rate according to reliance on single or multiple evidence of delivery of information: odds ratio, 0.165; 95% CI [0.07; 0.4] (Chi test: p=1.1×10). DISCUSSION: This study shows that surgeons, and orthopedic surgeons in particular, are more at risk of being investigated for failure to provide due patient information (D=-0.65 [-0.7; -0.6]). They are not, however, more at risk of conviction (p=0.49). Being in private practice also appeared to be a risk factor for conviction of failure to provide due information. Offering several rather than a single means of proof of delivery of information significantly reduces the risk of conviction (p=1.1×10). LEVEL OF EVIDENCE: Level IV: Retrospective study

Superluminal Localized Solutions To Maxwell Equations Propagating Along A Normal-sized Waveguide.

We show that localized (nonevanescent) solutions to Maxwell equations exist, which propagate without distortion along normal waveguides with superluminal speed.6406660

Superluminal Localized Solutions to Maxwell Equations propagating along a waveguide: The finite-energy case

In a previous paper of ours [Phys. Rev. E64 (2001) 066603, e-print physics/0001039] we have shown localized (non-evanescent) solutions to Maxwell equations to exist, which propagate without distortion with Superluminal speed along normal-sized waveguides, and consist in trains of "X-shaped" beams. Those solutions possessed therefore infinite energy. In this note we show how to obtain, by contrast, finite-energy solutions, with the same localization and Superluminality properties. [PACS nos.: 41.20.Jb; 03.50.De; 03.30.+p; 84.40.Az; 42.82.Et. Keywords: Wave-guides; Localized solutions to Maxwell equations; Superluminal waves; Bessel beams; Limited-dispersion beams; Finite-energy waves; Electromagnetic wavelets; X-shaped waves; Evanescent waves; Electromagnetism; Microwaves; Optics; Special relativity; Localized acoustic waves; Seismic waves; Mechanical waves; Elastic waves; Guided gravitational waves.]Comment: plain LaTeX file (12 pages), plus 10 figure