External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems

National communication policies : genesis, reception and evolution of the concept in democratic Catalonia

In the 21st century, the field of communication policies studies has launched a timely process of revision of notions of 'communication policy' and 'media policy' in the light of changes observed in their definition, scope and praxis. One of the central aspects of the discussion is the growing strength gained since the mid-1980s by private actors, supranational political organisations and independent bodies with regard to the definition, adoption and implementation of regulatory measures, to the detriment of state government leadership. This article aims to contribute to that debate in two ways. The first is to draw on 1970s' Latin-American thought on national communication policies (NCPs) as cultural autonomy and development tools. The second is to present how these ideas were received by a number of scholars in Catalonia in the 1980's and how they have re-elaborated the NCPs concept on the basis of the importance of public communication policies for national reconstruction in a stateless nation

An empirical investigation of parametric and semiparametric estimation methods in sample selection models

In this paper we analyze empirically different specifications of a sample selection model. We are interested in how the estimates vary across alternative assumptions concerning the joint conditional distribution of the sample selection equation errors, such us the specification of error distribution, the functional relationship of the index function and heteroskedasticity. To do this, we estimate a wage equation for the Spanish labor market using two different approaches: Maximum Likelihood and Two-Step Methods. For the latter, three alternative semiparametric procedures are used to compute the sample selection mechanism, and thus three alternative two-step estimators of the parameters of the wage equation are obtained. We compare theses estimates with Heckman's approach

Semiparametric three step estimation methods in labor supply models

The aim of this paper is to provide an alternative way of specification and estimation of a labor supply model. The proposed estimation procedure can be included in the so called predicted wage methods and its main interest is twofold .. First, under standard assumptions in studies of labor supply, the estimator based on predicted wages is shown to be consistent and asymptotically normal. Moreover, we propose also a consistent estimator of the asymptotic covariance matrix. In the main part of the paper we introduce a semiparametric estimator based on marginal integration techniques that allows for nonlinear relationships between the labor supply variable and its covariates. We show that also the wage equation could be modeled nonparametrically. The asymptotic properties of the estimators are given. Finally, in a detailed application we compare the results empirically against those obtained in standard three step estimators based on predicted wages

Diferències dialectals del català a partir de les oracions interogatives absolutes amb 'que'

Aquest estudi centra l'atenció en l'anàlisi dels paràmetres prosòdics (entonació, durada i intensitat) que caracteritzen les oracions interrogatives absolutes encapçalades per la conjunció «que». El corpus emprat ha estat el constituït per oracions completes de tres accents tonals obtingut en quatre punts d'enquesta (Barcelona, Tarragona, Lleida i Tortosa) a partir de mostres recollides a parlants femenines representatives del lloc en qüestió. Els resultats mostren clarament com l'anàlisi de l'F0 caracteritza la parla de cadascun dels quatre indrets estudiats sense confusió

Primera cita del elusivo calamar oceánico Thysanoteuthis rhombus Troschel, 1857 (Cephalopoda: Thysanoteuthidae) en la costa catalana

The diamondback squid Thysanoteuthis rhombus Troschel, 1857 is a large and elusive oceanic squid species. Here, we provide the first record of the species for the Catalan coast and integrate this finding in the current knowledge of the species in close areas.El chipirón volantín (Thysanoteuthis rhombus Troschel, 1857) es una especie de calamar oceánico grande y elusivo. En este trabajo se proporciona el primer registro de la especie para la costa catalana y se discute en el contexto de registros de la especie en zonas cercanas

Reseña: La realidad aumentada y su aplicación en el patrimonio cultural

La trascendencia del discurso de las nuevas tecnologías en el mundo actual es un tema delicado, habiendo posiciones encontradas en cuanto a su utilización y hegemonía. Sin embargo, la investigación de David Ruiz Torres nos lleva por otros derroteros. Más allá de ningún posicionamiento, el autor expone e ilustra con clarificadores ejemplos el concepto de realidad aumentada (AR), facilitándonos una definición propia: «tecnología que combina el mundo real con información generada por ordenador, obteniendo una percepción mejorada o aumentada del mismo, en la que esa información debe tener un registro tridimensional e insertarse en el entorno real del usuario de forma que ofrezca una impresión realista en la fusión de ambos mundos, de modo que pueda interactuar como si se tratase de elementos físicos reales».Y desde luego, logra el objetivo de ubicarla en el contexto de la disciplina humanística, apuntando una serie de posibilidades prometedoras en el ámbito cultural, patrimonial y museístico. Su texto es el resultado de una profunda lectura de selectos documentos consagrados a esta materia, pero sobre todo, es un compendio descriptivo de experiencias producto de esta novedosa tecnología

El mercado de los datos personales: la infuencia del big data en el remarketing = The personal data market: The influence of big data on remarketing

La gestión de datos se está convirtiendo en una de las prioridades de todo negocio que desarrolle su actividad de manera digital. Esa información les permite idear estrategias de marketing mucho más directas hacia sus clientes, revolucionando con ello el concepto que teníamos hasta ahora. Al mismo tiempo se han profesionalizado nuevas figuras encargadas de diseñar e instalar herramientas de rastreo, de análisis, perfilación y protección de datos personales, incluso profesionales encargados de vender o subastar información. Todo este desarrollo ha dado lugar a una reinvención del marketing digital con los términos Remarketing o Retargeting, que por medio de publicidad personalizada pretenden acercarse cada vez más al final del embudo del consumidor. En tal personalización es donde adquieren importancia los métodos de rastreo, de los que sobresalen las cookies. La clave se encuentra en que esta información es capaz de crear un mercado basado en el Big Data, denominado Mercado de Datos, el cual genera importantes ingresos a los estados, es un activo de gran valor para empresas y una herramienta de poder para los consumidores

Métodos de documentación arqueológica aplicados en arqueología subacuática: el modelo fotogramétrico y el fotomosaico del pecio fenicio Mazarrón-2 (Puerto de Mazarrón, Murcia)

In 2007, ARQVA – National Museum of Underwater Archaeology carried out an archaeological project at the Phoenician shipwreck Mazarron-2 (Port of Mazarron, Murcia, Spain). The aims of the project were to check the state of preservation of the hull remains of the ship as well as the metal structure that protects the site. Moreover, the available archaeological data on the shipwreck were updated for the purpose of creating a new digital archive of the site. A real scale photogrammetrical 3D model of the interior of the hull of the ship was created using the program Photomodeler. In addition, a high-resolution photomosaic of the ship was produced since this had not been done in the past. This article describes the methods employed in the realization of both the photogrammetrical model and the photomosaic. Finally, an evaluation is offered of the applications of these recording techniques for archaeological hull remains underwater