Comparing omnidirectional reflection from periodic and quasiperiodic one-dimensional photonic crystals

We determine the range of thicknesses and refractive indices for which omnidirectional reflection from quasiperiodic multilayers occurs. By resorting to the notion of area under the transmittance curve, we assess in a systematic way the performance of the different quasiperiodic Fibonacci multilayers.Comment: 5 pages, 4 color figures. Comments welcome

The transfer matrix: a geometrical perspective

We present a comprehensive and self-contained discussion of the use of the transfer matrix to study propagation in one-dimensional lossless systems, including a variety of examples, such as superlattices, photonic crystals, and optical resonators. In all these cases, the transfer matrix has the same algebraic properties as the Lorentz group in a (2+1)-dimensional spacetime, as well as the group of unimodular real matrices underlying the structure of the abcd law, which explains many subtle details. We elaborate on the geometrical interpretation of the transfer-matrix action as a mapping on the unit disk and apply a simple trace criterion to classify the systems into three types with very different geometrical and physical properties. This approach is applied to some practical examples and, in particular, an alternative framework to deal with periodic (and quasiperiodic) systems is proposed.Comment: 50 pages, 24 figure

Backward-wave regime and negative refraction in chiral composites

Possibilities to realize a negative refraction in chiral composites in in dual-phase mixtures of chiral and dipole particles is studied. It is shown that because of strong resonant interaction between chiral particles (helixes) and dipoles, there is a stop band in the frequency area where the backward-wave regime is expected. The negative refraction can occur near the resonant frequency of chiral particles. Resonant chiral composites may offer a root to realization of negative-refraction effect and superlenses in the optical region

Critical assessment of protein intrinsic disorder prediction (CAID) - Results of round 2

Protein intrinsic disorder (ID) is a complex and context-dependent phenomenon that covers a continuum between fully disordered states and folded states with long dynamic regions. The lack of a ground truth that fits all ID flavors and the potential for order-to-disorder transitions depending on specific conditions makes ID prediction challenging. The CAID2 challenge aimed to evaluate the performance of different prediction methods across different benchmarks, leveraging the annotation provided by the DisProt database, which stores the coordinates of ID regions when there is experimental evidence in the literature. The CAID2 challenge demonstrated varying performance of different prediction methods across different benchmarks, highlighting the need for continued development of more versatile and efficient prediction software. Depending on the application, researchers may need to balance performance with execution time when selecting a predictor. Methods based on AlphaFold2 seem to be good ID predictors but they are better at detecting absence of order rather than ID regions as defined in DisProt. The CAID2 predictors can be freely used through the CAID Prediction Portal, and CAID has been integrated into OpenEBench, which will become the official platform for running future CAID challenges

CAID prediction portal: A comprehensive service for predicting intrinsic disorder and binding regions in proteins

Intrinsic disorder (ID) in proteins is well-established in structural biology, with increasing evidence for its involvement in essential biological processes. As measuring dynamic ID behavior experimentally on a large scale remains difficult, scores of published ID predictors have tried to fill this gap. Unfortunately, their heterogeneity makes it difficult to compare performance, confounding biologists wanting to make an informed choice. To address this issue, the Critical Assessment of protein Intrinsic Disorder (CAID) benchmarks predictors for ID and binding regions as a community blind-test in a standardized computing environment. Here we present the CAID Prediction Portal, a web server executing all CAID methods on user-defined sequences. The server generates standardized output and facilitates comparison between methods, producing a consensus prediction highlighting high-confidence ID regions. The website contains extensive documentation explaining the meaning of different CAID statistics and providing a brief description of all methods. Predictor output is visualized in an interactive feature viewer and made available for download in a single table, with the option to recover previous sessions via a private dashboard. The CAID Prediction Portal is a valuable resource for researchers interested in studying ID in proteins. The server is available at the URL: https://caid.idpcentral.org

High seroprevalence of equine infectious anemia in workhorses from an endemic region in Northeast Argentina

La anemia infecciosa equina (AIE), también conocida como fiebre del pantano,es una enfermedad infecciosa causada por un virus ARN común en équidos,burros y mulas. Tiene una distribución mundial. El objetivo de este estudio fueinvestigar la prevalencia y la incidencia serológica de AIE en 118 caballos dela provincia de Corrientes, zona endémica del Nordeste Argentino, durante unperiodo de tres años (2014-2016). Se realizaron tres muestreos de un total de118 caballos de trabajo. Se obtuvieron muestras de sangre completa de cadacaballo y re-muestreos posteriores por punción yugular con agujas estériles,guantes y jeringas desechables. La prevalencia de AIE fue de 77,2% en 2014,81,3% en 2015 y 88,7% en 2016. La incidencia acumulada de la enfermedadfue de 0,30 en un año y de 0,35 en dos años. Considerando que la AIE es undesafío importante para los sistemas de producción de equinos en laArgentina, el éxito del control de la enfermedad requerirá el esfuerzo conjuntode autoridades sanitarias, veterinarios y propietarios de caballos.Equine infectious anemia (EIA), also known as swamp fever, is an infectious disease caused by an RNA virus common in equids, donkeys and mules. It has a worldwide distribution and is currently considered a global disease. The aim of this study was to investigate the serological incidence and prevalence of EIA in 118 horses from the province of Corrientes, an endemic area of Northeast Argentina, over three years (2014-2016). Three samplings of a total of 118 workhorses were performed. Whole blood samples of each horse and subsequent resamplings were obtained by jugular puncture with sterile needles, gloves and disposable syringes. EIA prevalence was 77.2% in 2014, 81.3% in 2015 and 88.7% in 2016. The accumulated incidence of the disease was 0.30 in one year and 0.35 in two years. Considering that EIA is a major challenge for equine production systems in Argentina, successful disease control will require the joint effort of sanitary authorities, veterinary practitioners and horse owners.Fil: Espasandin, Ana Gabriela. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cipolini, María F.. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Storani, Carlos A.. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Monzon, Nolly Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Martínez, Diana. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Diaz, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin