Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

Enclavijado de Ender en las fracturas del macizo trocantéreo: análisis retrospectivo de la ocupación del canal medular

Se revisaron las historias clínicas de 226 pacientes afectos de fracturas del macizo trocantérico, tratadas mediante enclavijado de Ender en un periodo de 9 años en el Hospital del Insalud de Barbastro. La estabilidad de las fracturas se determinó mediante la clasificación de Ramadier. Se valoró el porcentaje de ocupación de la cavidad medular femoral por los clavos de Ender y la posible relación de este parámetro con la migración del material de osteosíntesis. Se evaluó también la utilidad del bloqueo distal de los clavos de Ender con agujas de Kirschner, en la prevención de su migración distal. Se comprobó una relación significativa entre el porcentaje de ocupación del canal medular y la migración distal del material en las fracturas inestables. El bloqueo distal con aguja de Kirschner no se acompañó de una menor incidencia en la migración distal de los clavos.A retrospective study was done on 226 trochanteric fractures managed with Ender nails during a 9 years period at the Insalud Hospital of Barbastro. Stability of these fractures was classified following Ramadier's criteria. Filling of the medular cavity by Ender nails and its relation with osteosyntehsis migration was analysed. Distal locking of Ender nails by Kirschner pins was evaluated to prevent its distal mobilization. A significative relationship was observed between a high filling rate of the medular cavity and lower distal migration rate in unestable trochanteric fractures. Distal locking of Ender nails was not accompanied of lower rate of distal osteosynthesis migratio

Multi-Phase Flash Sintering: The Next Natural Step in Flash Sintering Evolution

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Addressing sustainable food management in hotels: proposing a framework and examining hotel groups

Purpose - Sustainable food practices have been recognised as a key issue in efforts to improve and report sustainable tourism practices, given the importance of the social, environmental and economic impacts of the food industry throughout its entire chain of production - from farm to fork. From this standpoint, the aim of the present paper is to propose a comprehensive framework for reporting or making decisions concerning sustainable food management in hotels, taking into account the various facets of the food supply chain. Design/methodology/approach - Several dimensions are proposed for dealing with sustainable food management, involving all aspects of food supply chains that may be relevant for hotel decision-making. Furthermore, some key criteria for creating and using indicators of different types (qualitative and quantitative) to address these various dimensions of sustainable food management are suggested. Subsequently, the proposed framework is validated with the sustainability criteria and indicators provided by the top eight hotel groups, according to the 2019 SAM Annual Corporate Sustainability Assessment. Findings - Hotels neglect a number of aspects of sustainable food management identified in the framework. The quality and the quantity of the information provided by hotels are limited. Practical implications - There is a need to improve sustainability in food management in the hotels under analysis in several areas. A comprehensive framework such as that proposed in this paper may be of great value in seeking to remedy this situation. It may also assist users of hotel services and communities in making more informed decisions. Originality/value - The proposed framework may be beneficial in advancing academic debate towards a more embracing and relevant understanding of sustainable food management in hotels and on the indicators required in this regard. Keywords Sustainability indicators, Sustainable supply chain, Food chain management, Food waste, Hotels Paper type Research pape

Kerker Conditions Upon Lossless, Absorption, and Optical Gain Regimes

The directionality and polarization of light show peculiar properties when the scattering by a dielectric sphere can be described exclusively by electric and magnetic dipolar modes. Particularly, when these modes oscillate in-phase with equal amplitude, at the so-called first Kerker condition, the zero optical backscattering condition emerges for non-dissipating spheres. However, the role of absorption and optical gain in the first Kerker condition remains unexplored. In this work, we demonstrate that either absorption or optical gain precludes the first Kerker condition and, hence, the absence of backscattered radiation light, regardless of the size of the particle, incident wavelength, and incoming polarization. Finally, we derive the necessary prerequisites of the second Kerker condition of the zero forward light scattering, finding that optical gain is a compulsory requirement

High-order dispersion mapping of an optical fiber

We report on measurements of high-order dispersion maps of an optical fiber, showing how the ratio between the third and fourth-order dispersion (β3/β4) and the zero-dispersion wavelength (λ0) vary along the length of the fiber. Our method is based on Four-Wave Mixing between short pulses derived from an incoherent pump and a weak laser. We find that the variations in the ratio β3/β4 are correlated to those in λ0. We present also numerical calculations to illustrate the limits on the spatial resolution of the method. Due to the good accuracy in measuring λ0 and β3/β4 (10 -3% and 5% relative error, respectively), and its simplicity, the method can be used to identify fiber segments of good uniformity, suitable to build nonlinear optical devices such as parametric amplifiers and frequency comb generators28342584273FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2012/50259-8; 2015/11779-4; 2017/16151-9; 2018/08988-9; 2019/16793-6Fundação de Amparo à Pesquisa do Estado de São Paulo (2012/50259-8, 2015/11779-4, 2017/16151-9, 2018/08988-9, 2019/16793-6); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS) (COL-10-2-05

Reactive Flash Sintering

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Electron temperature fluctuation measurements in the pedestal of improved confinement regimes at ASDEX Upgrade

US DOE (DE-SC0006419, DE-SC0014264, and DE- SC0017381)EUROfusion Consortium (No. 633053

Explainable Artificial Intelligence (XAI): Concepts, Taxonomies, Opportunities and Challenges toward Responsible AI

In the last few years, Artificial Intelligence (AI) has achieved a notable momentum that, if harnessed appropriately, may deliver the best of expectations over many application sectors across the field. For this to occur shortly in Machine Learning, the entire community stands in front of the barrier of explainability, an inherent problem of the latest techniques brought by sub-symbolism (e.g. ensembles or Deep Neural Networks) that were not present in the last hype of AI (namely, expert systems and rule based models). Paradigms underlying this problem fall within the so-called eXplainable AI (XAI) field, which is widely acknowledged as a crucial feature for the practical deployment of AI models. The overview presented in this article examines the existing literature and contributions already done in the field of XAI, including a prospect toward what is yet to be reached. For this purpose we summarize previous efforts made to define explainability in Machine Learning, establishing a novel definition of explainable Machine Learning that covers such prior conceptual propositions with a major focus on the audience for which the explainability is sought. Departing from this definition, we propose and discuss about a taxonomy of recent contributions related to the explainability of different Machine Learning models, including those aimed at explaining Deep Learning methods for which a second dedicated taxonomy is built and examined in detail. This critical literature analysis serves as the motivating background for a series of challenges faced by XAI, such as the interesting crossroads of data fusion and explainability. Our prospects lead toward the concept of Responsible Artificial Intelligence, namely, a methodology for the large-scale implementation of AI methods in real organizations with fairness, model explainability and accountability at its core. Our ultimate goal is to provide newcomers to the field of XAI with a thorough taxonomy that can serve as reference material in order to stimulate future research advances, but also to encourage experts and professionals from other disciplines to embrace the benefits of AI in their activity sectors, without any prior bias for its lack of interpretability

Protocol of sterile personal protective equipment for surgical personnel against SARS-CoV-2 during the COVID-19 pandemic

Background: COVID-19 represents the major pandemic seen the last years generating morbidity and mortality around the world. It is well known the propagation of the virus occurs by air mostly, so it is needed a barrier when the medic personal is treating suspect or confirm patients. Personal protective equipment represents a barrier between the health personnel and the patient during the COVID-19 pandemic. The surgical team during a COVID-19 confirmed o suspicious case procedure requires using PPE to be protected and keep the sterility for the patient safety.Methods: A team of surgeons from a 100% COVID-19 hospital of the Mexican institute of social security developed an inner protocol of safe use PPE maintaining sterility for the surgery.Conclusions: The protocol described provides safety to surgical team and the patient minimizing risk of surgical infections