La ley del precio unitario en la zona metropolitana fronteriza = The Law of one price in the Borderplex

RESUMEN Precios de menú en ocho franquicias son utilizados para examinar desviaciones de la paridad de precios entre México y Estados Unidos. Los productos de la muestra incluyen una variedad de artículos idénticos que se venden en ambos lados de la Frontera Norte. Los resultados ofrecen evidencia a favor de la paridad de precios. También indican que divergencias entre precios y tasas de cambio duran menos de lo que indican estudios anteriores. ABSTRACT Menu prices from eight restaurant franchises are utilized to examine departures from the law of one price. Products in the sample include a variety of identical menu items marketed on both sides of the border between the United States and Mexico. Results generally favor purchasing power parity. Deviations from parity are found to be much shorter that what is reported in earlier studies

El conocimiento didáctico del contenido (CDC) como herramienta para explicar las relaciones entre el contenido a enseñar y las estrategias didácticas en Biología

Enseñar el tema meiosis plantea desafíos a los profesores. En esta comunicación presentamos los resultados sobre el CDC en relación a la meiosis, enfocado en las fases de transferencia, enseñanza y evaluación. El objetivo fue indagar la importancia dada por los profesores al tema, la adecuación de la selección de contenidos al nivel educativo, las estrategias de enseñanza y los instrumentos de evaluación empleados por 7 profesoras en activo. Las representaciones fueron recogidas mediante un instrumento adaptado a partir del ReCo (Representación del Contenido, Loughran et al. , 2004). El CDC de este grupo muestra una transformación del conocimiento disciplinar limitada a una reducción y simplificación, una selección de contenidos y estrategias de enseñanza prescriptas en el diseño curricular e instrumentos de evaluación para comprobar la adquisición de conocimientos

OTELO survey: optimal emission-line flux determination with OSIRIS/GTC

Emission-line galaxies are important targets for understanding the chemical evolution of galaxies in the universe. Deep, narrow-band imaging surveys allow to detect and study the flux and the equivalent widths (EW) of the emission line studied. The present work has been developed within the context of the OTELO project, an emission line survey using the Tunable Filters (TF) of OSIRIS, the first generation instrument on the GTC 10.4m telescope located in La Palma, Spain, that will observe through selected atmospheric windows relatively free of sky emission lines. With a total survey area of 0.1 square degrees distributed in different fields, reaching a 5 \sigma depth of 10^-18 erg/cm^2/s and detecting objects of EW < 0.3 A, OTELO will be the deepest emission line survey to date. As part of the OTELO preparatory activities, the objective of this study is to determine the best combination of sampling and full width at half maximum (FWHM) for the OSIRIS tunable filters for deblending H\alpha from [NII] lines by analyzing the flux errors obtained. We simulated the OTELO data by convolving a complete set of synthetic HII galaxies in EW with different widths of the OSIRIS TFs. We estimated relative flux errors of the recovered H\alpha and [NII]6583 lines. We found that, for the red TF, a FWHM of 12 A and a sampling of 5 A is an optimal combination that allow deblending H\alpha from the [NII]6583 line with a flux error lower than 20%. This combination will allow estimating SFRs and metallicities using the H\alpha flux and the N2 method, respectively.Comment: 16 pages, 9 figures. Some authors added. Accepted for publication in PAS

The fish family Muraenidae: an ideal group for testing at small-scale the coherency of Macaronesia as a biogeographic unit, with the first report on separate fishery statistics

: The present study was conceptualized to study the muraenid species (moray eels) occurring around the volcanic archipelagos of the Azores, Madeira, Selvagens, Canary and Cabo Verde islands (eastern-central Atlantic). The biogeographic patterns of these species were analysed and compared. We then hypothesized that this fish family is an ideal group for testing at small-scale the coherency of Macaronesia and its direct biogeographic units: i.e. the Azores, Webbnesia and Cabo Verde, as proposed in recent scientific literature. Additionally, this paper provides for the first time separate fishery statistics for this group in the region that were analysed to contrast the biogeographic results.En prensa1,00

Research Note: Persistent Salmonella problems in slaughterhouses related to clones linked to poultry companies

Salmonellosis remains one of the main foodborne zoonoses in Europe, with poultry products as the main source of human infections. The slaughterhouse has been identified as a potential source for Salmonella contamination of poultry meat. Despite the mandatory programme of the EU, there are companies with persistent Salmonella that are unable to remove the bacteria from their processing environment, compromising the entire production line. In this context, an intensive sampling study was conducted to investigate a slaughterhouse with persistent Salmonella problems, establishing the genetic relationship among Salmonella strains isolated during the slaughter process. A total of 36 broiler flocks were sampled during processing at the slaughterhouse. Salmonella was identified based on ISO 6579-1:2017 (Annex D), serotyped by Kauffman-White-Le-Minor technique, and the genetic relationship was assessed with ERIC-PCR followed by PFGE. The outcomes showed that 69.4% of the batches sampled carried Salmonella upon arrival at the slaughterhouse and that 46.3% of the different samples from carcasses were contaminated with Salmonella. The two serovars isolated at the different steps in the slaughterhouse were Enteritidis (98.2%) and Kentucky (1.8%). Pulsed-field gel electrophoresis analysis revealed a low genetic diversity, with all S. Enteritidis isolates showing a nearly identical pulsotype (similarity >85%) and S. Kentucky strains showed the same XbaI PFGE profile (95.0% genetic similarity). The results of this study showed a high genetic relationship among isolates recovered from carcasses and environmental samples in the slaughterhouse from both Salmonella-positive and Salmonella-free flocks. Salmonella strains re-circulated across to poultry flocks and re-entered the slaughterhouse to survive on the processing line. Thus, it is necessary to implement molecular diagnosis methods in time at the field level to determine the Salmonella epidemiology of the flock, to make rapid decisions for the control of Salmonella and prevent entry into the slaughterhouse environment.info:eu-repo/semantics/publishedVersio

Aprender Arquitectura de Computadores con la herramienta Simula3MS

En este artículo se presenta la experiencia de uso de la herramienta Simula3MS en el laboratorio de las asignaturas de Arquitectura de Computadores en los estudios impartidos en la Facultad de Informática de la Universidade da Coruña y la Escuela Técnica Superior de Ingeniería de la Universidade de Santiago de Compostela. El objetivo de las prácticas es ilustrar, mediante un juego de ejercicios realizados sobre el simulador Simula3MS, cómo trabaja el procesador del computador. El simulador usa un subconjunto de instrucciones MIPS y varias configuraciones diferentes del procesador que se escogen según el objetivo de los ejercicios prácticos. En el artículo se describen los ejercicios que se proponen a los estudiantes en el laboratorio y se muestra un análisis sobre el impacto que ha tenido el uso del simulador en la actividad docente.Peer Reviewe