Rational characteristic functions and markov chains

Abstract 1 We investigate in this paper how to estimate the density function of a random variable using a parametric ARMA model for its characteristic function. The choice of this model is motivated by the fact that this type of density characterizes the duration of staying at an N-states Markov chain, but the approach is general enough to be applied to many practical problems. Both ML and moment-based linear estimates are derived, the former being based on the optimization of a highly non-linear function. 1.Peer ReviewedPostprint (published version

Silvopasture policy promotion in European Mediterranean areas

Silvopasture is the deliberate integration of a woody component with grazed pastures as understorey. It is one of the most extended agroforestry practices all over the world. Silvopasture use is key to increase the sustainability of livestock farming systems as silvopasture reduces the use of concentrates since the woody component provides feed for animals. However, it is not an extensively used practice in Europe. This paper aims at evaluating, from Eurostat, LUCAS database and the 118 rural development programs, the current situation of permanent grasslands in the Mediterranean area of Europe as well as the rural development programmes fostering silvopasture to better understand how sustainable land use systems are promoted and provide insights to foster silvopasture across Europe. The results of this study show that most of the policy measures related to silvopasture are adapted to the local necessity. The already existing agroforestry managed land (dehesas/montado) are related to measures supporting regeneration and maintenance while in those areas where agroforestry does not exist the measures are related to forest fire prevention.MRML was supported by the European Commission through the AFINET (grant agreement no 727872) and the Go-Grass projects (grant agreement no 862674) from the European Union´s H2020 Research and Innovation Programme (https://ec.europa.eu/programmes/horizon2020/ en) and the Open2preserve project (SOE2/P5/E0804) from the Interreg Sudoe Programme (https://interreg-sudoe.eu/gbr/home). ARR was supported by the Xunta de Galicia, Consellerı´a de Educación, Universidade e Formación Profesional (https://www.edu.xunta.gal/portal/es) through the Consolidation funds 2019–2022. NFD was also supported by the Xunta de Galicia, Consellerı´a de Educacio´n, Universidade e Formación Profesional (https://www.edu.xunta.gal/portal/es) (Programa de axudas a´ etapa posdoutoral modalide B DOG n˚ 213, 08/11/2019 p.48018, exp: ED481D 2019/009). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

Nuevos datos geocronológicos 40Ar-39Ar en dos puntos singulares del macizo de Anaga (Tenerife): Punta Poyata e Igueste de San Andrés. Consecuencias de interés

En este trabajo se aportan nuevos datos geocronológicos Ar40-Ar39 en rocas ancaramíticas submarinas localizadas en dos puntos singulares del macizo de Anaga (NE de Tenerife): las ancaramitas submarinas hidrotermalizadas de Punta Poyata (NNW de Anaga) y las lavas submarinas ancaramíticas del Barranco de Igueste (SE de Anaga). Las muestras estudiadas pertenecen a afloramientos pertenecientes a los niveles estratigráficos más inferiores de la secuencia volcánica que conforma el edificio de Anaga. En Punta Poyata se tomaron dos especímenes que dieron edades de 12,2 ± 1,9 Ma and 13,0 ± 1,0 Ma. En el barranco de Igueste los resultados geocronológicos de las muestras tomadas dieron edades de 12,7 ± 1,6 Ma and 9,7 ± 1,0 Ma. Estos datos sugieren que el macizo de Anaga comenzó su desarrollo subaéreo antes de lo que anteriormente se creía, ajustándose dicho período inicial al Mioceno Medio en lugar de al Mioceno tardío como previamente se asumía.This work provides new Ar40-Ar39 geochronological data in submarine ankaramite rocks located in two distant points of Anaga (NE Tenerife): the submarine hydrothermally altered ankaramites of Punta Poyata area (NNW Anaga) and the ankaramitic pillow lavas at Barranco de Igueste (SE Anaga). The studied samples were collected from outcrops of the lowest stratigraphic levels throughout the volcanics that build up the Anaga massif. At Punta Poyata, two collected samples yielded an age of 12,2 ± 1,9 Ma and 13,0 ± 1,0 Ma. At Barranco de Igueste, sample results are of 12,7 ± 1,6 Ma and 9,7 ± 1,0 Ma. These data support the assumption that the Anaga massif began its subaerial growth earlier than that previously was supposed, most likely in the Mid-Miocene Instead of late Miocene as currently believed.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Los Juegos de Alambre. Una experiencia de juego en una clase de grado

[ES] Este trabajo describe en profundidad el desarrollo de un juego específico, utilizado como herramienta para conseguir el siguiente propósito: comprobar el grado de adquisición de conocimiento de una asignatura así cómo afianzarlo. Se plantea como un método complementario a las metodologías tradicionales. El nuevo juego ha sido creado en el curso académico 2019/20 y se utilizó en dos grupos diferentes del Grado en Administración y Dirección de Empresas (uno impartido en inglés y otro impartido en español). El diseño del juego ha permitido lograr en buena medida objetivoscomo conocer mejor a los estudiantes, su nivel de implicación en la asignatura o el grado de interrelación existente entre ellos. También ha servido para obtener información valiosa de cara a la utilización más precisa de otras herramientas (tutorías, profundización teórica en aspectos concretos o estudio de casos).[EN] This work describes in detail the development of an educational game as a tool to check the degree of acquisition and consolidation of knowledge of the student in relation to a subject are . It is proposed as a complementary method to traditional methodologies. Thus, the article presents the devolpment of a brand new serious game which has been created in the 2019-20 academic year. Ithas been used in two different groups of the Degree in Business Management (one taught in English and the other one in Spanish). Based on previous gamification experiences, the design and use of the game has lead to the achievement of the goals pursued, generating also an important volume of valuable information that can increase the effectiveness of the use of other tools (tutorials, theoretical immersion in some specific subjects or case studies).Montero-Navarro, A.; Rodríguez-Sánchez, J.; Gallego-Losada, R.; González-Torres, T. (2020). The wire games. A gaming experience within a Grade Class. WPOM-Working Papers on Operations Management. 11(1):14-24. https://doi.org/10.4995/wpom.v11i1.12823OJS142411

Validation of an AutoRegressive Integrated Moving Average model for the prediction of animal zone temperature in a weaned piglet building

An AutoRegressive Integrated Moving Average model was validated for the prediction of temperatures in the animal zone of conventional weaned piglet barn. The validation period covered seven cycles and recorded values at 10-min intervals for 292 days. Average weight was 5.75 ± 0.86 kg at the beginning of the production cycle and 18.41 ± 2.12 kg at the end of the cycle. Mean outdoor air temperatures ranged 6.14 to 17.85 °C with deviations in the range 2.49 °C to 5.24 °C, which involved marked differences in the operation of the ventilation system. The Mean Average Percentage Error was below 4%, with a mean error of ≤1 °C. The Root Mean Square Error was in the range 0.77 °C to 1.19 °C, whereas the coefficient of determination ranged between 0.52 and 0.81. Despite the changes in environmental conditions and in animal weight and management, the accuracy of the model remained stable with low dispersion of values. The model showed good accuracy and reliability covering all the seasons under changing meteorological conditions because it considered the operation of the heating and ventilation systems and changes in animal weight. The residuals obtained from the validation of the seven production cycles were Gaussian distributed, which confirmed the validity of the model. The generated model can be used for more effective environmental control systems that are capable of anticipating events and show a better response, which helps improve energy savings and animal welfareThe authors are grateful to the regional government Xunta de Galicia for funding this research through the “Programme of consolidation and structuring of competitive research units” (GPC2014/072)S

Energy, Production and Environmental Characteristics of a Conventional Weaned Piglet Farm in North West Spain

Postweaning is one of the most sensitive and energy-demanding phases of swine production. The objective of this research was to assess the energy, production and environmental characteristics of a conventional farm with temperature-based environmental control. The selected energy, environmental and production variables were measured on farm, in a high livestock density area of NW Spain, for seven production cycles. The quantification of variables was aimed at obtaining the maximum performance with the lowest possible use of resources, focusing on animal welfare and production efficiency. The Brown–Forsythe, Welch and Games-Howell tests revealed significant differences in terms of temperature, relative humidity and CO2 concentrations among production cycles, and among the critical, postcritical and final periods. Improved humidity management resulted in a 17% reduction of climate control energy, which involved energy savings in the range of 33% to 47% per kg produced at the end of the postweaning cycle. Accordingly, adding humidity as a control variable could result in higher ventilation rates, thereby improving animal welfare, reducing heating energy use and increasing weight gain per unit climate control energy. In addition, the strong correlations found between heating energy and relative humidity (R2 = 0.73) and ventilation energy and CO2 (R2 = 0.99) suggest that these variables could be readily estimated without additional sensor costsThis research has received funding from European Regional Development Fund (ERDF) (2007–2013) under the project Control and automation strategies for energy and production efficiency in weaned farms, included in the research and innovation programme for Galicia, PEME I+D SumaS

Raman-Mössbauer-XRD studies of selected samples from “Los Azulejos” outcrop: A possible analogue for assessing the alteration processes on Mars

The outcrop of “Los Azulejos” is visible at the interior of the Cañadas Caldera in Tenerife Island (Spain). It exhibits a great variety of alteration processes that could be considered as terrestrial analogue for several geological processes on Mars. This outcrop is particularly interesting due to the content of clays, zeolite, iron oxides, and sulfates corresponding to a hydrothermal alteration catalogued as “Azulejos” type alteration. A detailed analysis by portable and laboratory Raman systems as well as other different techniques such as X ray diffraction (XRD) and Mössbauer spectroscopy has been carried out (using twin-instruments from Martian lander missions: Mössbauer spectrometer MIMOS-II from the NASA-MER mission of 2001 and the XRD diffractometer from the NASA-MSL Curiosity mission of 2012). The mineral identification presents the following mineral species: magnetite, goethite, hematite, anatase, rutile, quartz, gregoryite, sulphate (thenardite and hexahydrite), diopside, feldspar, analcime, kaolinite and muscovite. Moreover, the in-situ Raman and Micro-Raman measurements have been performed in order to compare the capabilities of the portable system specially focused for the next ESA Exo-Mars mission. The mineral detection confirms the sub-aerial alteration on the surface and the hydrothermal processes by the volcanic fluid circulations in the fresh part. Therefore, the secondary more abundant mineralization acts as the color agent of the rocks. Thus, the zeolite-illite group is the responsible for the bluish coloration, as well as the feldspars and carbonates for the whitish and the iron oxide for the redish parts. The XRD system was capable to detect a minor proportion of pyroxene, which is not visible by Raman and Mössbauer spectroscopy due to the “Azulejos” alteration of the parent material on the outcrop. On the other hand, Mössbauer spectroscopy was capable of detecting different types of iron-oxides (Fe3+/2+-oxide phases). These analyses emphasize the strength of the different techniques and the working synergy of the three different techniques together for planetary space missions.The work was supported by the MICINN with the Project AYA-2008-04529.Peer reviewe

Determination of Partition Coefficients of Selected Model Migrants between Polyethylene and Polypropylene and Nanocomposite Polypropylene

Studies on nanoparticles have focused the attention of the researchers because they can produce nanocomposites that exhibit unexpected hybrid properties. Polymeric materials are commonly used in food packaging, but from the standpoint of food safety, one of the main concerns on the use of these materials is the potential migration of low molecular substances from the packaging into the food. The key parameters of this phenomenon are the diffusion and partition coefficients. Studies on migration from food packaging with nanomaterials are very scarce. This study is focused on the determination of partition coefficients of different model migrants between the low-density polyethylene (LDPE) and polypropylene (PP) and between LDPE and nanocomposite polypropylene (naPP). The results show that the incorporation of nanoparticles in polypropylene increases the mass transport of model migrants from LDPE to naPP. This quantity of migrants absorbed into PP and naPP depends partially on the nature of the polymer and slightly on the chemical features of the migrant. Relation () between partition coefficient and partition coefficient at 60°C and 80°C shows that only BHT at 60°C has a less than 1. On the other hand, bisphenol A has the highest with approximately 50 times more.The study was financially supported by the Xunta de Galicia (Project no. INCITE08PXIB203096). R. Sendon is grateful to the “Parga Pondal” Program financed by “Consellería de Innovación e Industria, Xunta de Galicia” for her postdoctoral contractS