Artífices del 1911: Alfredo Wiechers y Miguel Pou, centenario de un monumento: Mausoleo del Cuerpo de Bomberos de Ponce

English Abstract.Abstracto en Españo

Birkhoff's Theorem for Three-Dimensional AdS Gravity

All three-dimensional matter-free spacetimes with negative cosmological constant, compatible with cyclic symmetry are identified. The only cyclic solutions are the 2+1 (BTZ) black hole with SO(2) x R isometry, and the self-dual Coussaert-Henneaux spacetimes, with isometry groups SO(2) x SO(2,1) or SO(2) x SO(2).Comment: 11 pages, RevTeX4; minor typos corrected, Ref. added, accepted for publication in Phys. Rev.

A Methodology for Classifying Search Operators as Intensification or Diversification Heuristics

Selection hyper-heuristics are generic search tools that dynamically choose, from a given pool, the most promising operator (low-level heuristic) to apply at each iteration of the search process. The performance of these methods depends on the quality of the heuristic pool. Two types of heuristics can be part of the pool: diversification heuristics, which help to escape from local optima, and intensification heuristics, which effectively exploit promising regions in the vicinity of good solutions. An effective search strategy needs a balance between these two strategies. However, it is not straightforward to categorize an operator as intensification or diversification heuristic on complex domains. Therefore, we propose an automated methodology to do this classification. This brings methodological rigor to the configuration of an iterated local search hyper-heuristic featuring diversification and intensification stages. The methodology considers the empirical ranking of the heuristics based on an estimation of their capacity to either diversify or intensify the search. We incorporate the proposed approach into a state-of-the-art hyper-heuristic solving two domains: course timetabling and vehicle routing. Our results indicate improved performance, including new best-known solutions for the course timetabling problem

First record of the genus Semiopyla Simon, 1901 (Araneae: Salticidae: Sitticini) From Colombia

Las arañas saltarinas son el grupo más diverso dentro del orden Araneae, distribuidas en casi todos los continentes y habitando una amplia variedad de microhábitats, incluyendo los manglares. En un estudio sobre arañas saltarinas en los manglares del sur del Golfo de Morrosquillo, se recolectaron especímenes del género Semiopyla Simon, 1901 mediante muestreo de hojarasca y recolección manual. Este estudio pretende reportar por primera vez la presencia de este género en Colombia, específicamente de la especie S. cataphracta Simon, 1901. Adicionalmente, el estudio incluye mapas de distribución basados en registros nuevos y anteriores, junto con observaciones ecológicas de la especie en bosques de manglar.Jumping spiders are the most diverse group within the order Araneae, distributed across nerly all continents, and inhabiting a wide variety of microhabitats, including mangrove forests. In a study of jumping spiders in the mangrove forests of the southern Gulf of Morrosquillo, specimens of the genus Semiopyla Simon, 1901 were collected through leaf litter sampling and manual collection. This study aims to report the presence of this genus in Colombia for the first time, specifically the species S. cataphracta Simon, 1901. Additionally, the study includes distribution maps based on new and previous records, along with ecological observations on the species in mangrove forests

Sistema de Información Geográfica aplicado al Diseño de Obras de Conservación de Aguas y Suelos

107 p.El objetivo del presente trabajo es desarrollar una aplicación web que permita el diseño de obras de conservación de aguas y suelos, entregando una solución práctica y de fácil utilización para una gran gama de usuarios. Se comienza el trabajo describiendo el contexto de la aplicación, definiendo el problema a resolver y fijando los objetivos a lograr. Se presentan trabajos relacionados al tema abordado, considerando tanto trabajos académicos como comerciales. Luego se entrega una revisión de la literatura existente en torno a los sistemas de información geográfica, sus componentes, tipos de sistemas, tipos de arquitecturas empleadas, los tipos de integración con otros sistemas y los modelos de datos más utilizados en sus implementaciones. A continuación se entrega la descripción del proceso de desarrollo del software que implementa un SIG básico aplicado a diseño de obras de conservación de aguas y suelos. Se incluyen en este capítulo tópicos tales como metodología de desarrollo, requerimientos funcionales, contexto de la aplicación, arquitectura del sistema, definición de módulos, requerimiento de datos, etc. Se detalla además la integración de un servidor de mapas al sistema, a fin de disponer de las funcionalidades básicas de un sistema de información geográfica para la localización de las estaciones y su correcta utilización en los cálculos de diseño de obras.Se definen los criterios de evaluación de los resultados obtenidos del proceso de desarrollo, y la comparación del método de trabajo propuesto con las alternativas existentes. Finalmente se presenta un análisis de los resultados obtenidos. Para terminar se entregan sugerencias relacionadas a nuevas funcionalidades por desarrollar, y observaciones acerca del proceso de desarrollo realizado. Palabras clave: SIG, diseño, obras, conservación, aguas, suelos, canales, zanjas./ABSTRACT: The goal of this work is to develop a web-based application to design soil and water conservation works, giving a practical and easy to use solution for many kinds of users. The application context is described, the problem is defined and the solution is delimited. Academic studies and commercial applications related to the present study are reviewed. In the literature review, system types and components, architecture, application integration and typical data models are discussed. The software development process is described for implementing a basic GIS in the soil and water conservation field. This includes development methodology, functional requirements, application context, system architecture, module definition and data requirements as well as other issues. The integration of a map server with the software provides the basic GIS functionality to assist users in locating representative precipitation stations and to facilitate correct design procedures. The criteria used in evaluation of the development process are defined and a comparison is made between the proposed and alternative approaches. The final results are analyzed and suggestions made for extending the functionality of the system, and regarding the system development process. Keywords: Web-based GIS, design, soil, water, conservation

Sistema de informacion geografica aplicado al diseno de obras de conservacion de aguas y suelos

107 p.El objetivo del presente trabajo es desarrollar una aplicación web que permita el diseño de obras de conservación de aguas y suelos, entregando una solución práctica y de fácil utilización para una gama de usuarios. Se comienza el trabajo describiendo el contexto de aplicación, definiendo el problema a resolver y fijando los objetivos a lograr. Se presentan trabajos relacionados al tema abordado, considerando tanto trabajos académicos como comerciales. Luego se entrega una revisión de la literatura existente en torno a los sistemas de información geográfica, sus componentes, tipos de sistemas, tipos de arquitecturas empleadas, los tipos de integración con otros sistemas y los modelos de datos más utilizados en sus implementaciones. A continuación se entrega la descripción del proceso de desarrollo del software que implementa un SIG básico aplicado a diseño de obras de conservación de aguas y suelos

Direct measurements of the correlation between reentrant ferromagnetism and lattice expansion in FeCuZr alloys

Amorphous metastable alloy of nominal composition [Fe_(0.5)Cu_(0.5)]_(87)Zr_(13) has been synthesized by high-energy ball milling. The alloy exhibit a ferromagnetic behavior with a Curie Temperature of T_(C)=255 K, as determined from low-field measurements whereas no transition to a paramagnetic state is observed under high- enough applied magnetic fields. The evolution of hysteresis loops with temperature as well as thermoremanence measurements indicate an anomalous magnetic behavior characterized by a spontaneous increase in the magnetization values as well as by a magnetic hardening when the temperature is increased above T_(C). These effects are strongly correlated with a dilation of the Fe-Fe nearest-neighbor distances, as determined from extended x-ray absorption fine structure (EXAFS) studies. EXAFS results indicate an almost negligible thermal expansion at temperatures below T_(C) while normal thermal expansion takes place at higher temperatures. Such expansion seems to promote a reinforcement of the ferromagnetic interactions among Fe-Fe atoms that would account for the observed spontaneous increase in the magnetization as well as for the evolution of the coercive field

Augmented reality for ESL/EFL and bilingual education: an international comparison

In recent decades, educational technologies have enabled new opportunitiesfor teaching and learning on a recurrent basis. In contemporary educationalcontexts, which are mainly oriented towards active methodologies and studentcentered approaches, educational technologies have led to a significantbreakthrough in education. Among emergent educational technologies, it isinteresting to specifically highlight the current importance of Augmented Reality(AR), which allows overlaying of virtual objects (that is, ‘augmented’ elements)into the real world. This paper, after exploring the potential of AR in education, isaimed at comparing pre-service English as a Second Language (ESL), English asa Foreign Language (EFL) and Bilingual Education (BE) teachers’ perceptions,uses and preferences (n = 53) from two universities (Texas Woman’s University,USA, and University of Córdoba, Spain) regarding the use of AR, and analyzewhether there are similarities and/or differences based on sociocultural context,approaches to education or teacher practices. The findings reveal the positiveattitudes towards integrating AR in ESL/EFL and bilingual contexts of theparticipants of the two institutions. The most noted advantages of AR are thatit enhances classroom engagement and its focus is different from traditionalteaching methods, increasing student motivation and facilitating their learningprocesses. Some reported challenges imposed by AR are that access to mobiledevices is limiting, the cost of technology, technical issues and the necessityfor specialized teacher training. We also found other challenges and numerousadvantages of AR usage in ESL/EFL and bilingual contexts, which are discussedthoroughly. Finally, current needs in the field are identified and suggestions areoffered for further research in AR for ESL/EFL and BE

Implementación de sistema de gestión de calidad utilizando herramientas CASE

El presente trabajo propone un modelo y prototipo de software resultado de la aplicación de la metodología de desarrollo incremental, utilizando la herramienta GeneXus. El mismo se aplicó a la gestión de la calidad a la asignatura “diseño basado en conocimiento”, de la Carrera Licenciatura de en Análisis de Sistemas de la Universidad Nacional de Salta (U.N.Sa). La experiencia demostró que la aplicación de la metodología y la herramienta elegida contribuyeron a la mejora de la calidad en la educación superior en la asignatura.Eje: Ingeniería de Software.Red de Universidades con Carreras en Informátic

Study X-ray photoelectron spectroscopy determination of interactions between gold nanoparticles and epidermal growth factor for potential use in biomedicine

Nowadays, biomedical applications of gold nanoparticles coupled with Epidermal Growth Factor have attracted huge attention because of its theranostic activity, which could be useful for diagnosis and treatment of neurodegenerative diseases. Therefore, there is a great interest to know the nature of the intermolecular interactions between the gold nanoparticles and epidermal growth factor (EGF). A two-step synthesis was performed. In the first step, gold nanoparticles were synthesized by chemical reduction of tetrachloroauric acid using sodium citrate as reducing and capping agent. Secondly, gold nanoparticles were coupled with EGF. The obtained nanoparticles were characterized by ultraviolet-visible spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and zeta-potential before and after being coupled with the EGF. Gold nanoparticles with an average diameter of 8.09 nm were obtained. After coupled with EGF, the particle average diameter increased to 9.14 nm. X-ray photoelectron spectroscopy showed an electrostatic interaction between gold nanoparticles and EGF. Zeta potential corroborated these results. Thus, it was possible for the first time to identify the interactions between these two chemical species. Since gold nanoparticles may act as carriers of EGF, these results illustrate the great potential for the use of this bionanocomposite in neurodegenerative disease treatment.UAEME