Discrete nonlinear Schrödinger equations for periodic optical systems : pattern formation in \chi(3) coupled waveguide arrays

Discrete nonlinear Schrödinger equations have been used for many years to model the propagation of light in optical architectures whose refractive index profile is modulated periodically in the transverse direction. Typically, one considers a modal decomposition of the electric field where the complex amplitudes satisfy a coupled system that accommodates nearest neighbour linear interactions and a local intensity dependent term whose origin lies in the χ (3) contribution to the medium's dielectric response. In this presentation, two classic continuum configurations are discretized in ways that have received little attention in the literature: the ring cavity and counterpropagating waves. Both of these systems are defined by distinct types of boundary condition. Moreover, they are susceptible to spatial instabilities that are ultimately responsible for generating spontaneous patterns from arbitrarily small background disturbances. Good agreement between analytical predictions and simulations will be demonstrated

Super-resolution track-density imaging studies of mouse brain: Comparison to histology

The recently proposed track-density imaging (TDI) technique was introduced as a means to achieve superresolution using diffusion MRI. This technique is able to increase the spatial resolution of the reconstructed images beyond the acquired MRI resolution by incorporating information from whole-brain fibre-tracking results. It not only achieves super-resolution, but also provides very high anatomical contrast with a new MRI contrast mechanism. However, the anatomical information-content of this novel contrast mechanism has not yet been assessed. In this work, we perform such a study using diffusion MRI of ex vivo mouse brains acquired at 16.4T, to compare the results of the super-resolution TDI technique with histological staining (myelin and Nissl stains) in the same brains. Furthermore, a modified version of the directionally-encoded colour TDI map using short-tracks is introduced, which reduces the TDI intensity dynamic range, and therefore enhances the directionality colour-contrast. Good agreement was observed between structures visualised in the superresolution TDI maps and in the histological sections, supporting the anatomical information-content of the images generated using the TDI technique. The results therefore show that the TDI methodology does provide meaningful and rich anatomical contrast, in addition to achieving super-resolution. Furthermore, this study is the first to show the application of TDI to mouse brain imaging: the high-resolution, high-quality images demonstrate the useful complementary information that can be achieved using super-resolution TDI

Identification of sixteen grapevine rootstocks by RFLP and RFLP analysis of nuclear DNA extracted from the wood

Sixteen rootstocks of the Vitis genus have been identified by the RFLP analysis methodology with the restriction enzyme HinfI. Uniques or moderately repeated DNA sequences of the nuclear genome of the Chardonnay V. vinifera variety were used as probes. RFLP analysis of 5 clones of SO 4 (V. berlandieri x V. riparia) and of 3 clones of 41 B Mgt (V. berlandieri x V. vinifera) with 4 probes and HinfI did not lead to any polymorphism. This is not surprising because of the vegetative origin of the clones. A simple method of nuclear DNA extraction of wood is described for the grapevine. We propose now the RFLP analysis methodology to complement or to replace in certain cases the ampelographical methods of identification of the rootstocks. The extension of this application to the V. vinifera varieties is considered.Identification de 16 porte-greffes de vigne par analyse RFLP, et analyse RFLP d'ADN nucléaire extrait à partir du boisNous avons identifié 16 porte-greffes du genre Vitis par la méthodologie d'analyse du polymorphisme de longueur des fragments de restriction (RFLP) de l'ADN avec l'enzyme de restriction HinfI. Pour cela, nous avons utilisé comme sondes des fragments d'ADN uniques ou peu répétés du génome de la variete Chardonnay de Vitis vinifera. L'analyse RFLP de cinq clones de SO 4 (V. berlandieri x V. riparia) et de trois clones de 41 B Mgt (V. berlandieri x V. vinifera) avec quatre sondes RFLP et l'enzyme HinfI n'a pas permis de différencier les clones d'un même hybride, dont les genomes sont extrêmement proches puisqu'ils sont obtenus de façon végétative. Nous présentons aussi une méthode simple d'extraction d'ADN nucléaire à partir du bois de vigne. Les analyses RFLP de cet ADN ont donné des résultats identiques à ceux obtenus avec l'ADN des feuilles. Nous sommes maintenant en mesure de proposer que la méthodologie d'analyse RFLP complète ou remplace dans certains cas les méthodes ampélographiques d'identification des portegreffes du genre Vitis. L'élargissement de cette application est envisagé pour les varietes de Vitis vinifera

Experiences and needs of direct support staff working with people with intellectual disabilities during the COVID-19 pandemic:A thematic analysis

Background The present study aimed to explore the experiences and needs of direct support staff during the initial stage of the COVID‐19 lockdown in the Netherlands. Method Overall, eleven direct support staff were recruited from five intellectual disability services to participate in this descriptive qualitative study. They recorded 34 audio messages during the considered period. Thematic analysis was used to analyse these audio recordings. Results Four themes emerged: (1) Emotional impact, which pertained to various emotions they experienced in their work; (2) Cognitive impact, which referred to challenges and changes they had undergone in their work; (3) Practical impact, which centred on the practical impact of the pandemic on their work; and (4) Professional impact, which concerned their experiences with other professionals. Conclusions This study provides valuable insights into the experiences and needs of direct support staff during the COVID‐19 pandemic, which, in turn, can help inform practice in preparation for a second wave of COVID‐19 or another future pandemic

The experiences of psychologists working with people with intellectual disabilities during the COVID-19 crisis

BACKGROUND: The aim of this study was to explore the experiences of psychologists working with people with intellectual disabilities during the initial stage of the COVID‐19 lockdown in the Netherlands. METHOD: Five psychologists, who were affiliated with three intellectual disability services, participated in this descriptive qualitative study. Overall, they recorded 22 audio messages during the period under examination, which were analysed using thematic analysis. RESULTS: Three themes were identified: (a) Working from home; (b) Adapting to the new reality; and (c) Advising and coaching support staff. CONCLUSIONS: This study provides critical insights into the experiences of psychologists working with people with intellectual disabilities during the initial stage of the COVID‐19 lockdown. These insights can help policymakers and practitioners to prepare for either a potential second wave of COVID‐19 or a future pandemic

Arthroscopic treatment of an intra-articular hemangioma in the posterior compartment of the knee

AbstractWe report the case of a 37-year-old patient presenting with knee pain and recurrent effusion without instability due to an intra-articular hemangioma in the posterior compartment of the knee. MRI showed features suggesting a diagnosis of hemangioma. Arthroscopic excision of the tumor was performed and the diagnosis was confirmed histologically. There was no recurrence after 5 years of follow-up

Picosecond fluctuating protein energy landscape mapped by pressure–temperature molecular dynamics simulation

Microscopic statistical pressure fluctuations can, in principle, lead to corresponding fluctuations in the shape of a protein energy landscape. To examine this, nanosecond molecular dynamics simulations of lysozyme are performed covering a range of temperatures and pressures. The well known dynamical transition with temperature is found to be pressure-independent, indicating that the effective energy barriers separating conformational substates are not significantly influenced by pressure. In contrast, vibrations within substates stiffen with pressure, due to increased curvature of the local harmonic potential in which the atoms vibrate. The application of pressure is also shown to selectively increase the damping of the anharmonic, low-frequency collective modes in the protein, leaving the more local modes relatively unaffected. The critical damping frequency, i.e., the frequency at which energy is most efficiently dissipated, increases linearly with pressure. The results suggest that an invariant description of protein energy landscapes should be subsumed by a fluctuating picture and that this may have repercussions in, for example, mechanisms of energy dissipation accompanying functional, structural, and chemical relaxation

Évolution de la qualité de vie après un traumatisme crânien par accident de la route : un suivi à cinq ans de la cohorte ESPARR

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Parallel Controllability Methods For the Helmholtz Equation

The Helmholtz equation is notoriously difficult to solve with standard numerical methods, increasingly so, in fact, at higher frequencies. Controllability methods instead transform the problem back to the time-domain, where they seek the time-harmonic solution of the corresponding time-dependent wave equation. Two different approaches are considered here based either on the first or second-order formulation of the wave equation. Both are extended to general boundary-value problems governed by the Helmholtz equation and lead to robust and inherently parallel algorithms. Numerical results illustrate the accuracy, convergence and strong scalability of controllability methods for the solution of high frequency Helmholtz equations with up to a billion unknowns on massively parallel architectures