Optical pulse propagation in a switched-on photonic lattice: Rabi effect with the roles of light and matter interchanged

A light pulse propagating in a suddenly switched on photonic lattice, when the central frequency lies in the photonic band gap, is an analog of the Rabi model where the two-level system is the two resonant (i.e. Bragg-coupled) Fourier modes of the pulse, while the photonic lattice serves as a monochromatic external field. A simple theory of these Rabi oscillations is given and confirmed by the numerical solution of the corresponding Maxwell equations. This is a direct, i.e. temporal, analog of the Rabi effect, additionally to the spatial analog in optical beam propagation described in Opt. Lett. 32, 1920 (2007). An additional high-frequency modulation of the Rabi oscillations reflects the lattice-induced energy transfer between the electric and magnetic fields of the pulse.Comment: 3 pages, 5 figure

Temporary Fixation Using a Long Femoral-tibial Nail to Treat a Displaced Medial Tibial Plateau Fracture in a 90-year-old Patient: A Case Report.

Introduction: Tibial plateau fractures are complex injuries in the elderly population. When traditional methods of fixation are not suitable, an alternative method needs to be chosen for a favorable outcome. We demonstrate a previously undescribed treatment for displaced tibial plateau fractures in the very elderly with poor soft-tissue integrity. Case Report: A 90-year-old woman suffered an open, Gustilo Grade IIIA, displaced fracture of the tibial plateau. An intramedullary knee arthrodesis, the femoral-tibial nail was used to temporarily stabilize her fracture. She was able to weight bear immediately postfixation. Conclusion: A long femoral-tibial nail allows favorable fracture and soft tissue healing, ease of nursing and immediate full weight-bearing. It shows good promise and should be considered as a management option when traditional methods are not applicable in select patients

The Sentinel Effect and Financial Reporting Aggressiveness in the Healthcare Industry

The sentinel effect posits that the perception of increased oversight is associated with improved behavior. We consider the association between enhanced government oversight and financial reporting aggressiveness in the healthcare industry. Specifically, we examine the association between criminal cases (pending cases and successful cases) against healthcare providers and the quality of subjective accounts that require significant judgment and have been shown to be linked to healthcare earnings management – revenue accruals and the allowance for doubtful accounts. We find that heightened government oversight is associated with lower financial reporting aggressiveness

Photonic Bloch oscillations and Zener tunneling in two-dimensional optical lattices

We report on the first experimental observation of photonic Bloch oscillations and Zener tunneling in two-dimensional periodic systems. We study the propagation of an optical beam in a square photonic lattice superimposed on a refractive index ramp, and demonstrate the tunneling of light from the first to the higher-order transmission bands of the lattice bandgap spectrum, associated with the spectral dynamics inside the first Brillouin zone and corresponding oscillations of the primary beam.Comment: 4 pages, 4 figure

Nonlinear localized modes at phase-slip defects in waveguide arrays

We study light localization at a phase-slip defect created by two semi-infinite mismatched identical arrays of coupled optical waveguides. We demonstrate that the nonlinear defect modes possess the specific properties of both nonlinear surface modes and discrete solitons. We analyze stability of the localized modes and their generation in both linear and nonlinear regimes.Comment: 3 pages, 6 figures, submitted to Opt. Let

Mid-term functional outcome after the internal fixation of distal radius fractures

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Distal radius fracture is a common injury with a variety of operative and non-operative management options. There remains debate as to the optimal treatment for a given patient and fracture. Despite the popularity of volar locking plate fixation, there are few large cohort or long term follow up studies to justify this modality. Our aim was to report the functional outcome of a large number of patients at a significant follow up time after fixation of their distal radius with a volar locking plate. Methods 180 patients with 183 fractures and a mean age of 62.4 years were followed up retrospectively at a mean of 30 months (Standard deviation = 10.4). Functional assessment was performed using the Disabilities of the Arm, Shoulder and Hand (DASH) and modified MAYO wrist scores. Statistical analysis was performed to identify possible variables affecting outcome and radiographs were assessed to determine time to fracture union. Results The median DASH score was 2.3 and median MAYO score was 90 for the whole group. Overall, 133 patients (74%) had a good or excellent DASH and MAYO score. Statistical analysis showed that no specific variable including gender, age, fracture type, post-operative immobilisation or surgeon grade significantly affected outcome. Complications occurred in 27 patients (15%) and in 11 patients were major (6%). Conclusion This single centre large population series demonstrates good to excellent results in the majority of patients after volar locking plate fixation of the distal radius, with complication rates comparable to other non-operative and operative treatment modalities. On this basis we recommend this mode of fixation for distal radius fractures requiting operative intervention.Peer Reviewe

Short courses of daily prednisolone during upper respiratory tract infections reduce relapse frequency in childhood nephrotic syndrome

Background Relapses of childhood nephrotic syndrome (NS) are frequently precipitated by viral upper respiratory tract infections (URTIs). A review of the literature reveals that in patients with steroid-dependent NS on alternate day corticosteroids, a short course of daily corticosteroid therapy during the course of an URTI may reduce relapse frequency. Objective To assess the effect of a short course of low-dose corticosteroid therapy during the course of an URTI on relapse frequency in patients with steroid-sensitive NS who have not been taking any treatment for a minimum period of 3 months. Methods A double-blind placebo-controlled crossover trial was conducted on 48 patients with idiopathic NS who had not been receiving corticosteroid therapy for a minimum of 3 months. Patients were randomized into two groups. Group A received 5 days of daily prednisolone at 0.5 mg/kg at the onset of an URTI while group B received 5 days of placebo. Both groups were followed up for 1 year and the URTI-induced relapse frequency was noted. A crossover was performed during the next year, with group A receiving placebo and group B receiving prednisolone. Results Thirty-three patients completed the study. In the treatment group, 115 episodes of URTI led to 11 relapses while in the control group 101 episodes of URTI led to 25 relapses. There was no significant difference between the mean number of URTIs between the treatment and control groups. The treatment group had significantly less relapses compared to the control group (p = 0.014). Within the treatment group, 65.6% did not relapse, while the remainder had a single relapse. In contrast, only 40.6% of the control group remained in remission while 40.6% suffered a single relapse and 18.8% had two or more relapses. Conclusions Prescribing a short course of daily corticosteroids during an URTI significantly reduces the frequency of URTI-induced relapse in patients with steroid-responsive NS who are off corticosteroid therapy

Observation of localized modes at phase slips in two-dimensional photonic lattices

We study experimentally light localization at phase-slip waveguides and at the intersection of phase-slips in a two-dimensional (2D) square photonic lattice. Such system allows to observe a variety of effects, including the existence of spatially localized modes for low powers, the generation of strongly localized states in the form of discrete bulk and surface solitons, as well as a crossover between one-dimensional (1D) and 2D localization.Comment: 4 double-column pages, 6 figures, submitted for publicatio

How common are vascular injuries in open tibial fractures? A prospective longitudinal cohort study.

BACKGROUND: Tibial fractures have an incidence of 15% of all adult fractures. They have been shown to have the highest incidence of non-union in long bone fractures and the highest incidence of vascular injury. Evidence from the literature suggests that a good vascular supply is important to ensure bone union. The aim of our study was to prospectively assess the incidence of vascular injuries in open tibial fractures and determine whether they were associated with an increased risk of non-union. METHODS: We performed a prospective study to investigate the incidence of arterial injuries with computed tomography angiography (CTA) in patients with Gustilo-Anderson grade I-III open tibial fractures between 2013 and 2015. CTA was performed with the trauma series at acute admission and reported by two independent musculoskeletal radiologists. Patients were followed up with clinical and radiographic assessment for 1 year. RESULTS: We recruited 77 patients into the study, and 56 patients (47 males, 9 females) were available for the final analysis, between 16 and 90 years of age. At the initial assessment, 29% had signs of arterial injury with active extravasation in 5%. The most common site of injury was in the diaphysis (87.5%), and the commonest mechanism was a road traffic accident. We found no significant relation between occult vascular injury and non-union (p > 0.05). CONCLUSION: The incidence of vascular injury in open tibial fractures is 29%, and CTA is therefore a useful test in identifying vascular injuries that may require vascular intervention