Numerical Distribution Functions for Seasonal Unit Root Tests

When working with time series data observed at intervals smaller than a year, it is often necessary to test for the presence of seasonal unit roots. One of the most widely used methods for testing seasonal unit roots is that of HEGY, which provides test statistics with non-standard distributions. This paper describes a generalisation of this method for any periodicity and uses a response surface regressions approach to calculate the critical values and P values of the HEGY statistics whatever the periodicity and sample size of the data. The algorithms are prepared with the Gretl open source econometrics package and some new tables of critical values for daily, hourly and half-hourly data are presented.seasonality, unit roots, surface response analysis

De novo malignancies following liver transplantation: impact and recommendations

1. De novo malignancy is one of the leading causes of late mortality after liver transplantation. 2. The risks of skin cancers and lymphoma are more than 10-fold greater than the risks in an age-matched and sex-matched general population. 3. Some types of neoplasia, such as lung, head and neck, and colorectal cancer, are more frequent in liver transplant recipients than in an age-matched and sexmatched population. The risks of other frequent malignancies, such as prostate and breast cancer, do not seem to be increased. 4. The most important risks for posttransplant malignancy are Epstein-Barr virus seronegativity (for lymphoma), sun exposure (for skin cancer), smoking, and increasing age. 5. Despite the absence of evidence, general recommendations (such as avoidance of overimmunosuppression, sunlight protection, and cessation of smoking) should be given. Screening protocols may help to detect neoplasia at an early stage of disease

Numerical Distribution Functions for Seasonal Unit Root Tests

When working with time series data observed at intervals smaller than a year, it is often necessary to test for the presence of seasonal unit roots. One of the most widely used methods for testing seasonal unit roots is that of HEGY, which provides test statistics with non-standard distributions. This paper describes a generalisation of this method for any periodicity and uses a response surface regressions approach to calculate the critical values and P values of the HEGY statistics whatever the periodicity and sample size of the data. The algorithms are prepared with the Gretl open source econometrics package and some new tables of critical values for daily, hourly and half-hourly data are presented.Financial support from research project ECO2010-15332 from Ministerio de Ciencia e Innovación, and Econometrics Research Group IT-334-07 from the Basque Government are gratefully acknowledged. The SGI/IZO-SGIker UPV/EHU is gratefully aknowledged for its generous allocation of computational resource

Open cluster Dolidze 25: Stellar parameters and the metallicity in the Galactic Anticentre

The young open cluster Dolidze 25, in the direction of the Galactic Anticentre, has been attributed a very low metallicity, with typical abundances between $-0.5$ and $-0.7$ dex below solar. We intend to derive accurate cluster parameters and accurate stellar abundances for some of its members. We have obtained a large sample of intermediate- and high-resolution spectra for stars in and around Dolidze 25. We used the FASTWIND code to generate stellar atmosphere models to fit the observed spectra. We derive stellar parameters for a large number of OB stars in the area, and abundances of oxygen and silicon for a number of stars with spectral types around B0. We measure low abundances in stars of Dolidze 25. For the three stars with spectral types around B0, we find $0.3$ dex (Si) and $0.5$ dex (O) below the values typical in the solar neighbourhood. These values, even though not as low as those given previously, confirm Dolidze 25 and the surrounding H II region Sh2-284 as the most metal-poor star-forming environment known in the Milky Way. We derive a distance $4.5\pm0.3\:$kpc to the cluster ($r_{\textrm{G}}\approx12.3\:$kpc). The cluster cannot be older than $\sim3\:$Myr, and likely is not much younger. One star in its immediate vicinity, sharing the same distance, has Si and O abundances at most $0.15\:$dex below solar. The low abundances measured in Dolidze 25 are compatible with currently accepted values for the slope of the Galactic metallicity gradient, if we take into account that variations of at least $\pm0.15\:$dex are observed at a given radius. The area traditionally identified as Dolidze 25 is only a small part of a much larger star-forming region that comprises the whole dust shell associated with Sh2-284 and very likely several other smaller H II regions in its vicinity.Comment: Accepted for publication in Astronomy \& Astrophysics. 16 pages, 12 figure

Behavior of propagating and evanescent components in azimuthally polarized non-paraxial fields

The contribution of the propagating and the evanescent waves associated with freely propagating non-paraxial light fields whose transverse component is azimuthally polarized at some plane is investigated. Analytic expressions are derived for describing both the spatial shape and the relative weight of the propagating and the evanescent components integrated over the transverse plane. The analysis is carried out within the framework of the plane-wave angular spectrum approach. These results are used to illustrate the behavior of a kind of donut-like beams with transverse azimuthal polarization at some plane

An approach to the teaching of pronunciation in Primary Education in Spain

The aim of this research study is mainly to introduce me to the world of research in English classroom, the main components that a research must have and the most relevant research methods. This work also presents an overview of the different methodologies prevailing in the teaching of English as a foreign language throughout the last two centuries and a description of the methodology that is commonly followed nowadays. It will also attempt a description of the most typical pronunciation problems that Spanish learners present by the time they learn English language. Finally, with the aim of conclude which method is the best to teach pronunciation, a research will be implemented in two groups of students of the same age

Desarrollo de un método de reflexión estructurada como estrategia docente en la adquisición de competencia diagnóstica en alumnos de Medicina

Memoria ID-0102. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

Desarrollo, aplicación y evaluación de una estrategia, basada en el modelo GOLE, para el aprendizaje autodirigido en el Rotatorio de Medicina Interna

Memoria ID-0116. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2016-2017

Implementación de una metodología ‘sandwich e-learning’ para mejorar la adquisición de competencias en las prácticas del Grado de Medicina. Formación virtual 2.0

Memoria ID-0107. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018

Implementación y análisis de modelos de co-enseñanza (“co-teaching”) en la asignatura de Rotatorio en Medicina Interna. Utilización de metodologías en línea (“on-line”)

Memoria ID-104. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020.[ES]El objetivo principal es implementar y analizar los resultados de la aplicación de un modelo seleccionado de co-enseñanza (“co-teaching”) en la asignatura de Rotatorio del Grado en Medicin