A Demonstration of Spectral and Spatial Interferometry at THz Frequencies

A laboratory prototype spectral/spatial interferometer has been constructed to demonstrate the feasibility of the double Fourier technique at Far Infrared (FIR) wavelengths (0.15 - 1 THz). It is planned to use this demonstrator to investigate and validate important design features and data processing methods for future astronomical FIR interferometer instruments. In building this prototype we have had to address several key technologies to provide an end-end system demonstration of this double Fourier interferometer. We report on the first results taken when viewing single slit and double slit sources at the focus of a large collimator used to simulate real sources at infinity. The performance of the prototype instrument for these specific field geometries is analyzed to compare with the observed interferometric fringes and to demonstrate image reconstruction capabilities.Comment: Accepted for publication in Applied Optic

Meningitis purulenta aséptica o meningitis que responde a corticoesteroides

En esté trabajo presentamos el primer caso diagnosticado en nuestro Hospital de una meningitis purulenta aséptica, o meningitis que responde a corticosteroides. Incluimos además una revisión de este tipo de meningitis caninas y de su posible etiopatogenia.This paper is a case report of the first diagnosed dog with Aseptic Purulent Meningitis, or Corticosteroid-responsive Meningitis, in our Hospital. It includes a review of this type of disease in the dog and its possible ethiopathogenesis

Multimode simulations of a wide field of view double-Fourier far-infrared spatio-spectral interferometer

In the absence of 50-m class space-based observatories, subarcsecond astronomy spanning the full far-infrared wavelength range will require space-based long-baseline interferometry. The long baselines of up to tens of meters are necessary to achieve subarcsecond resolution demanded by science goals. Also, practical observing times command a field of view toward an arcminute (1′) or so, not achievable with a single on-axis coherent detector. This paper is concerned with an application of an end-to-end instrument simulator PyFIInS, developed as part of the FISICA project under funding from the European Commission’s seventh Framework Programme for Research and Technological Development (FP7). Predicted results of wide field of view spatio–spectral interferometry through simulations of a long-baseline, double-Fourier, far-infrared interferometer concept are presented and analyzed. It is shown how such an interferometer, illuminated by a multimode detector can recover a large field of view at subarcsecond angular resolution, resulting in similar image quality as that achieved by illuminating the system with an array of coherent detectors. Through careful analysis, the importance of accounting for the correct number of higher-order optical modes is demonstrated, as well as accounting for both orthogonal polarizations. Given that it is very difficult to manufacture waveguide and feed structures at sub-mm wavelengths, the larger multimode design is recommended over the array of smaller single mode detectors. A brief note is provided in the conclusion of this paper addressing a more elegant solution to modeling far-infrared interferometers, which holds promise for improving the computational efficiency of the simulations presented here

The Wide-Field Spatio-Spectral Interferometer: System Overview, Data Synthesis and Analysis

The Wide-field Imaging Interferometry Testbed (WIIT) is a double Fourier (DF) interferometer operating at optical wavelengths, and provides data that are highly representative of those from a space-based far-infrared interferometer like SPIRIT. We have used the testbed to observe both geometrically simple and astronomically representative test scenes. Here we present an overview of the astronomical importance of high angular resolution at the far infrared, followed by the description of the optical set-up of WIIT, including the source simulator CHIP (Calibrated Hyperspectral Image Projector). We describe our synthesis algorithms used in the reconstruction of the input test scenes via a simulation of the most recent measurements. The updated algorithms, which include instruments artifacts that allow the synthesis of DF experimental data, are presented and the most recent results analyzed

ENTORNO Y NECESIDADES DE SALUD DE LA POBLACIÓN MAYOR DE 75 AÑOS NO ATENDIDA EN CUATRO ÁREAS BÁSICAS DE SALUD DE BARCELONA.

Objetivo: Observar y describir el entorno en que viven las personas mayores de 75 años que no acuden a centros de salud de la red pública y analizar sus necesidades de salud. Participantes y métodos. Diseño: Estudio observacional, descriptivo, transversal. Ámbito: Cuatro Areas Básicas de Salud (ABS) de la Dirección de Atención Primaria Sant Martí de Barcelona (ABS El Clot, ABS La Pau, ABS Verneda Nord y ABS Verneda Sud), que atienden una población de 80.373 habitantes, 4810 mayores de 75 años, según datos del padrón 1996. Sujetos: Ancianos >75 años asignados a las ABS, que no habían acudido en ninguna ocasión al Centro de Atención Primaria de Salud, identificados mediante el Sistema de Información de Atención Primaria (SIAP). Del total de >75 años (n= 4810), cumplieron requisitos 1666 (34,63%) . Medidas: Cuestionario semiestructurado administrado mediante entrevista en el domicilio; se recogió información sobre edad, género, convivencia, características del cuidador, de los edificios y de la vivienda, problemas de salud y necesidades alteradas según el modelo de V. Henderson, Escala de Arnel modificada y diagnósticos médicos autodeclarados. Resultados: De los 1666 ancianos identificados, respondieron el cuestionario 227 (13,62%). Las causas más frecuentes de no respuesta fueron: defunción, cambio domicilio, no localización y no desear participar. Características de los entrevistados: media de edad 81.55 (DE 4.29), 60,79% mujeres. El 20,26% viven solos, el 33 % con su esposo/a. Tienen cuidador el 33,92%, siendo mujeres más del 70%. El 35,68% tienen barreras arquitectónicas y el 68,72% ascensor. El 85,46% tienen calefacción. El 37% referían diagnósticos médicos, siendo los más prevalentes: ansiedad, depresión, dolor y problemas cardiovasculares. De los diagnósticos enfermeros según la nomenclatura de la NANDA Nursing Diagnoses, el 34,36% presentaron deterioro de la movilidad física, 51% dolor y 13,6% estreñimiento crónico. Más del 90% no se sienten útiles, pero con estabilidad emocional, buena comunicación, buenas relaciones familiares y no se sienten solos. Conclusiones: Se evidencia una notable falta de actualización en las bases de datos poblacionales del SIAP. Las personas entrevistadas son mayoritariamente mujeres, que más de la mitad viven solas o con parejas de la misma edad. Tienen cuidador 1/3 mayoritariamente mujeres. Existen barreras arquitectónicas en los edificios y en su domicilio, tienen calefacción y ducha. Los problemas de salud mental son los más frecuentes, seguidos del dolor y de los cardiovasculares. Los diagnósticos enfermeros más frecuentes son deterioro de la movilidad física, dolor y estreñimiento crónico. Más de un 90% de los ancianos dicen no sentirse útiles, pero manifiestan que no se sienten solos

Quasi-optical analysis of a far-infrared spatio-spectral space interferometer concept

FISICA (Far-Infrared Space Interferometer Critical Assessment) was a three year study of a far-infrared spatio-spectral double-Fourier interferometer concept. One of the aims of the FISICA study was to set-out a baseline optical design for such a system, and to use a model of the system to simulate realistic telescope beams for use with an end-to-end instrument simulator. This paper describes a two-telescope (and hub) baseline optical design that fulfils the requirements of the FISICA science case, while minimising the optical mass of the system. A number of different modelling techniques were required for the analysis: fast approximate simulation tools such as ray tracing and Gaussian beam methods were employed for initial analysis, with GRASP physical optics used for higher accuracy in the final analysis. Results are shown for the predicted far-field patterns of the telescope primary mirrors under illumination by smooth walled rectangular feed horns. Far-field patterns for both on-axis and off-axis detectors are presented and discussed

CREB decreases astrocytic excitability by modifying subcellular calcium fluxes via the sigma-1 receptor

Altres ajuts: La Marató de TV3 (TV3-20141430)Astrocytic excitability relies on cytosolic calcium increases as a key mechanism, whereby astrocytes contribute to synaptic transmission and hence learning and memory. While it is a cornerstone of neurosciences that experiences are remembered, because transmitters activate gene expression in neurons, long-term adaptive astrocyte plasticity has not been described. Here, we investigated whether the transcription factor CREB mediates adaptive plasticity-like phenomena in astrocytes. We found that activation of CREB-dependent transcription reduced the calcium responses induced by ATP, noradrenaline, or endothelin-1. As to the mechanism, expression of VP16-CREB, a constitutively active CREB mutant, had no effect on basal cytosolic calcium levels, extracellular calcium entry, or calcium mobilization from lysosomal-related acidic stores. Rather, VP16-CREB upregulated sigma-1 receptor expression thereby increasing the release of calcium from the endoplasmic reticulum and its uptake by mitochondria. Sigma-1 receptor was also upregulated in vivo upon VP16-CREB expression in astrocytes. We conclude that CREB decreases astrocyte responsiveness by increasing calcium signalling at the endoplasmic reticulum-mitochondria interface, which might be an astrocyte-based form of long-term depression

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): First Flight

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter far-infrared (30-100 m) double-Fourier Michelson interferometer designed to fly on a high altitude scientific balloon. The project began in 2011, and the payload was declared ready for flight in September 2016. Due to bad weather, the first flight was postponed until June 2017; BETTII was successfully launched on June 8, 2017 for an engineering flight. Over the course of the one night flight, BETTII acquired a large amount of technical data that we are using to characterize the payload. Unfortunately, the flight ended with an anomaly that resulted in destruction of the payload. In this paper, we will discuss the path to BETTII flight, the results of the first flight, and some of the plans for the future

Optical and Quasi-Optical Analysis of System Components for a Far-Infrared Space Interferometer

Many important astrophysical processes occur at wavelengths that fall within the far-infrared band of the EM spectrum, and over distance scales that require sub-arc second spatial resolution. It is clear that in order to achieve sub-arc second resolution at these relatively long wavelengths (compared to optical/near-IR), which are strongly absorbed by the atmosphere, a space-based far-IR interferometer will be required. We present analysis of the optical system for a proposed spatial-spectral interferometer, discussing the challenges that arise when designing such a system and the simulation techniques employed that aim to resolve these issues. Many of these specific challenges relate to combining the beams from multiple telescopes where the wavelengths involved are relatively short (compared to radio interferometry), meaning that care must be taken with mirror surface quality, where surface form errors not only present potential degradation of the single system beams, but also serve to reduce fringe visibility when multiple telescope beams are combined. Also, the long baselines required for sub-arc second resolution present challenges when considering propagation of the relatively long wavelengths of the signal beam, where beam divergence becomes significant if the beam demagnification of the telescopes is not carefully considered. Furthermore, detection of the extremely weak far-IR signals demands ultra-sensitive detectors and instruments capable of operating at maximum efficiency. Thus, as will be shown, care must be taken when designing each component of such a complex quasioptical system

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): towards the first flight

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is a balloon-borne, far-infrared direct detection interferometer with a baseline of 8 m and two collectors of 50 cm. It is designed to study galactic clustered star formation by providing spatially-resolved spectroscopy of nearby star clusters. It is being assembled and tested at NASA Goddard Space Flight Center for a first flight in Fall 2016. We report on recent progress concerning the pointing control system and discuss the overall status of the project as it gets ready forits commissioning flight