Quantization of Weyl invariant unimodular gravity with antisymmetric ghost fields

The enforcement of the unimodularity condition in a gravity theory by means of a Lagrange multiplier leads, in general, to inconsistencies upon quantization. This is so, in particular, when the classic linear splitting of the metric between the background and quantum fields is used. To avoid the need of introducing such a Lagrange multiplier while using the classic linear splitting, we carry out the quantization of unimodular gravity with extra Weyl symmetry by using Becchi-Rouet-Stora-Tyutin (BRST) techniques. Here, two gauge symmetries are to be gauge-fixed: transverse diffeomorphisms and Weyl transformations. We perform the gauge-fixing of the transverse diffeomorphism invariance by using BRST transformations that involve antisymmetric ghost fields. We show that these BRST transformations are compatible with the BRST transformations needed to gauge-fix the Weyl symmetry, so that they can be combined in a set of transformations generated by a single BRST operator. Newton's law of gravitation is derived within the BRST formalism we put forward as well as the Slavnov-Taylor equation.Comment: 24 pages, 1 table, 1 figur

Wannier-based calculation of the orbital magnetization in crystals

We present a first-principles scheme that allows the orbital magnetization of a magnetic crystal to be evaluated accurately and efficiently even in the presence of complex Fermi surfaces. Starting from an initial electronic-structure calculation with a coarse ab initio k-point mesh, maximally localized Wannier functions are constructed and used to interpolate the necessary k-space quantities on a fine mesh, in parallel to a previously-developed formalism for the anomalous Hall conductivity [X.Wang, J. Yates, I. Souza, and D. Vanderbilt, Phys. Rev. B 74, 195118 (2006)]. We formulate our new approach in a manifestly gauge-invariant manner, expressing the orbital magnetization in terms of traces over matrices in Wannier space. Since only a few (e.g., of the order of 20) Wannier functions are typically needed to describe the occupied and partially occupied bands, these Wannier matrices are small, which makes the interpolation itself very efficient. The method has been used to calculate the orbital magnetization of bcc Fe, hcp Co, and fcc Ni. Unlike an approximate calculation based on integrating orbital currents inside atomic spheres, our results nicely reproduce the experimentally measured ordering of the orbital magnetization in these three materials.Comment: 13 pages, 3 figures, 4 table

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

Campaña de comunicación integral para la marca "Avena Swift"

Este trabajo tiene como finalidad crear una campaña de comunicación integral para la marca “Avena Swift”. La cual estará apuntada hacia Mujeres jóvenes (Millennials), amas de casa con o sin hijos, residentes en Lima Metropolitana; pertenecientes a los niveles socioeconómicos A y B. Los objetivos de esta campaña serán comunicar el lanzamiento de la marca destacando sus beneficios diferenciales y romper con el insight relacionado a que la comida instantánea siempre hace daño a la salud y/o es menos nutritiva que la comida elaborada de forma tradicional.The purpose of this work is to create a comprehensive communication campaign for the brand “Avena Swift”. Which will be aimed at young housewives with or without children, residents of Metropolitan Lima, belonging to socioeconomic groups A and B. The objectives of this campaign will be to communicate the launch of the brand, highlighting its differential benefits and breaking with the insight that instant food is always harmful to the health and / or is less nutritious than food prepared in a traditional way

DNA double strand break repair in Escherichia coli perturbs cell division and chromosome dynamics

To prevent the transmission of damaged genomic material between generations, cells require a system for accommodating DNA repair within their cell cycles. We have previously shown that Escherichia coli cells subject to a single, repairable site-specific DNA double-strand break (DSB) per DNA replication cycle reach a new average cell length, with a negligible effect on population growth rate. We show here that this new cell size distribution is caused by a DSB repair-dependent delay in completion of cell division. This delay occurs despite unperturbed cell size regulated initiation of both chromosomal DNA replication and cell division. Furthermore, despite DSB repair altering the profile of DNA replication across the genome, the time required to complete chromosomal duplication is invariant. The delay in completion of cell division is accompanied by a DSB repair-dependent delay in individualization of sister nucleoids. We suggest that DSB repair events create inter-sister connections that persist until those chromosomes are separated by a closing septum

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

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

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