Design of pixel-level ADCs for energy-sensitive hybrid pixel detectors

Single-photon counting hybrid pixel detectors have shown\ud to be a valid alternative to other types of X-ray imaging\ud devices due to their high sensitivity, low noise, linear behavior\ud and wide dynamic range. One important advantage of these\ud devices is the fact that detector and readout electronics are\ud manufactured separately. This allows the use of industrial\ud state-of-the-art CMOS processes to make the readout\ud electronics, combined with a free choice of detector material\ud (high resistivity Silicon, GaAs or other). By measuring not\ud only the number of X-ray photons but also their energies (or\ud wavelengths), the information content of the image increases,\ud given the same X-ray dose. We have studied several\ud possibilities of adding energy sensitivity to the single photon\ud counting capability of hybrid pixel detectors, by means of\ud pixel-level analog-to-digital converters. We show the results of\ud simulating different kinds of analog-to-digital converters in\ud terms of power, area and speed

Spectroscopic quantum imaging using pixel-level ADCs in semiconductor-based hybrid pixel detectors

This thesis describes the design of a microelectronic system that can be used to build a spectroscopic imaging system, in particular a spectroscopic quantum imaging using pixel-level ADCs in semiconductor-based hybrid pixel detectors. In such a system the signal generated in the sensor by a photon interaction is electronically processed to obtain a measurement of the energy deposited by the photon. This measurement is expressed as a digital value and read from the pixel by the appropriate circuitry located in the periphery of the chip. The digital data corresponding to the measurement (energy of the photon and pixel address in the imaging array) is then read from the chip by an external data acquisition system for further processing or visual presentation

Relation between diet type and modification in the human intestinal microbiota. Systematic bibliographic review

Los cambios en la dieta pueden haber afectado en la composición de la microbiota intestinal, creciendo el interés por la modulación de la dieta y conseguir una microbiota intestinal favorable para promover la salud. Objetivo: Conocer los cambios que generan diferentes tipos de dieta en la microbiota intestinal humana. Material y métodos: Se realiza una revisión bibliográfica sistemática utilizando las bases de datos: Medline a través de Pubmed, CINALH, Biblioteca Cochrane, CUIDEN y Gredos (Repositorio documental de la Universidad de Salamanca). Publicados entre 2015 y 2019. Resultados: Se seleccionaron 10 estudios, sobre la modificación causada por los macronutrientes y el uso de probióticos y prebióticos en distintas alteraciones de la microbiota intestinal. Conclusión: La dieta es un potente modificador de la microbiota intestinal, una composición favorable de ésta promueve la salud. Los ácidos grasos de cadena corta, resultantes de la fermentación de carbohidratos no digeribles, han demostrado diferentes beneficios y ser terapéuticos novedosos muy prometedores. Los prebióticos y probióticos y los polifenoles han demostrado también beneficios en el restablecimiento de alteraciones de la microbiota intestinal

Spanish generation from Spanish Sign Language using a phrase-based translation system

This paper describes the development of a Spoken Spanish generator from Spanish Sign Language (LSE – Lengua de Signos Española) in a specific domain: the renewal of Identity Document and Driver’s license. The system is composed of three modules. The first one is an interface where a deaf person can specify a sign sequence in sign-writing. The second one is a language translator for converting the sign sequence into a word sequence. Finally, the last module is a text to speech converter. Also, the paper describes the generation of a parallel corpus for the system development composed of more than 4,000 Spanish sentences and their LSE translations in the application domain. The paper is focused on the translation module that uses a statistical strategy with a phrase-based translation model, and this paper analyses the effect of the alignment configuration used during the process of word based translation model generation. Finally, the best configuration gives a 3.90% mWER and a 0.9645 BLEU

Evaluating a Speech Communication System for deaf people

This paper describes the development of an Advanced Speech Communication System for Deaf People and its field evaluation in a real application domain: the renewal of Driver’s License. The system is composed of two modules. The first one is a Spanish into Spanish Sign Language (LSE: Lengua de Signos Española) translation module made up of a speech recognizer, a natural language translator (for converting a word sequence into a sequence of signs), and a 3D avatar animation module (for playing back the signs). The second module is a Spoken Spanish generator from sign-writing composed of a visual interface (for specifying a sequence of signs), a language translator (for generating the sequence of words in Spanish), and finally, a text to speech converter. For language translation, the system integrates three technologies: an example-based strategy, a rule-based translation method and a statistical translator. This paper also includes a detailed description of the evaluation carried out in the Local Traffic Office in the city of Toledo (Spain) involving real government employees and deaf people. This evaluation includes objective measurements from the system and subjective information from questionnaires. Finally, the paper reports an analysis of the main problems and a discussion about possible solutions

Language Resources for Spanish - Spanish Sign Language (LSE) translation

This paper describes the development of a Spanish Spanish Sign Language (LSE) translation system. Firstly, it describes the first Spanish Spanish Sign Language (LSE) parallel corpus focused on two specific domains: the renewal of the Identity Document and Driver’s License. This corpus includes more than 4,000 Spanish sentences (in these domains), their LSE translation and a video for each LSE sentence with the sign language representation. This corpus also contains more than 700 sign descriptions in several sign writing specifications. The translation system developed with this corpus consists of two modules: a Spanish into LSE translation module that is composed of a speech recognizer (for decoding the spoken utterance into a word sequence), a natural language translator (for converting a word sequence into a sequence of signs) and a 3D avatar animation module (for playing back the signs). The second module is a Spanish generator from LSE made up of a visual interface (for specifying a sequence of signs in sign writing), a language translator (for generating the sequence of words in Spanish) and a text to speech converter. For each language translation, the system uses three technologies: an example based strategy, a rule based translation method and a statistical translator

Sistema de Comunicación Oral para Personas Sordas

Este artículo describe el desarrollo y la evaluación de un sistema de comunicación para personas sordas en un ámbito de aplicación específico: la renovación del permiso de conducir. El sistema de comunicación desarrollado está compuesto por dos módulos que permiten la comunicación en los dos sentidos. El primer módulo es un traductor de voz en castellano a Lengua de Signos Española (LSE) y está formado por un reconocedor de voz, un traductor de palabras en castellano a una secuencia de signos y un tercer módulo de representación de los signos mediante un agente animado. El segundo módulo es un generador de voz en castellano a partir de una secuencia de signos, y está formado por una interfaz donde se especifican los signos, un traductor (para convertir la secuencia de signos en una secuencia de palabras) y un conversor de texto a voz. En los dos módulos de traducción entre lenguas, se integran tres tecnologías: una basada en ejemplos, una basada en reglas y un traductor estadístico. Este artículo describe la evaluación del sistema llevada a cabo en la Jefatura Provincial de Tráfico de Toledo implicando a funcionarios de dicha jefatura y personas sordas

Clinical significance of donor-specific human leukocyte antigen antibodies in liver transplantation

Antibody-mediated rejection (AMR) caused by donorspecific anti-human leukocyte antigen antibodies (DSA) is widely accepted to be a risk factor for decreased graft survival after kidney transplantation. This entity also plays a pathogenic role in other solid organ transplants as it appears to be an increasingly common cause of heart graft dysfunction and an emerging issue in lung transplantation. In contrast, the liver appears relatively resistant to DSA-mediated injury. This “immune-tolerance” liver property has been sustained by a low rate of liver graft loss in patients with preformed DSA and by the intrinsic liver characteristics that favor the absorption and elimination of DSA; however, alloantibody-mediated adverse consequences are increasingly being recognized, and several cases of acute AMR after ABO-compatible liver transplant (LT) have been reported. Furthermore, the availability of new solid-phase assays, allowing the detection of low titers of DSA and the refinement of objective diagnostic criteria for AMR in solid organ transplants and particularly in LT, have improved the recognition and management of this entity. A cost-effective strategy of DSA monitoring, avoidance of class ? human leukocyte antigen mismatching, judicious immunosuppression attached to a higher level of clinical suspicion of AMR, particularly in cases unresponsive to conventional antirejection therapy, can allow a rational approach to this threat

High Pretransplant BAFF Levels and B-cell Subset Polarized towards a Memory Phenotype as Predictive Biomarkers for Antibody-Mediated Rejection

Antibody-mediated rejection (AbMR) is one of the leading causes of graft loss in kidney transplantation and B cells play an important role in the development of it. A B-cell activating factor (BAFF) is a cytokine involved in B cell ontogeny. Here, we analyzed whether B cell maturation and the e ect of B cell soluble factors, such as BAFF could be involved in AbMR. Serum BAFF levels and B and T cell subpopulations were analyzed 109 kidney transplant patients before transplantation and at 6 and 12 months after kidney transplantation. Pretransplant serum BAFF levels as well as memory B cell subpopulations were significantly higher in those patients who su ered clinical AbMR during the first 12 months after kidney transplantation. Similar results were observed in the prospective analysis of patients with subclinical antibody-mediated rejection detected in the surveillance biopsy performed at 12 months after kidney transplantation. A multivariate analysis confirmed the independent role of BAFF in the development of AbMR, irrespective of other classical variables. Pretransplant serum BAFF levels could be an important non-invasive biomarker for the prediction of the development of AbMR and posttransplant increased serum BAFF levels contribute to AbMR

Sistema de traducción de lenguaje SMS a castellano

En este artículo se describe el proceso llevado a cabo para desarrollar un sistema de traducción de lenguaje SMS (Short Message Service) a castellano. En primer lugar, se genera una base de datos necesaria para desarrollar el sistema, formada por más de 11000 términos y expresiones en lenguaje SMS y sus traducciones al castellano, así como frases de ejemplo en lenguaje SMS para realizar una primera evaluación del sistema. La arquitectura completa está formada por un traductor automático estadístico basado en subfrases o secuencias de palabras y una serie de funciones implementadas para actuar sobre las frases en tiempo real. La evaluación de la arquitectura se realiza con las siguientes métricas: WER (tasa de error de palabras), BLEU (“BiLingual Evaluation Understudy”) y NIST. Como resultado final, se obtiene una tasa de error de palabra de 20,2% para el mejor experimento