On the heterochromatic number of hypergraphs associated to geometric graphs and to matroids

The heterochromatic number hc(H) of a non-empty hypergraph H is the smallest integer k such that for every colouring of the vertices of H with exactly k colours, there is a hyperedge of H all of whose vertices have different colours. We denote by nu(H) the number of vertices of H and by tau(H) the size of the smallest set containing at least two vertices of each hyperedge of H. For a complete geometric graph G with n > 2 vertices let H = H(G) be the hypergraph whose vertices are the edges of G and whose hyperedges are the edge sets of plane spanning trees of G. We prove that if G has at most one interior vertex, then hc(H) = nu(H) - tau(H) + 2. We also show that hc(H) = nu(H) - tau(H) + 2 whenever H is a hypergraph with vertex set and hyperedge set given by the ground set and the bases of a matroid, respectively

Microextraction of ochratoxin A in raw wheat with supramolecular solvents

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Nanostructured-solvent for the extraction of ochratoxin A in Andalusian wines

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Mechanical characterisation of tungsten-1wt.% yttrium oxide as a function of temperature and atmosphere

This study evaluates the mechanical behaviour of an Y2O3-dispersed tungsten (W) alloy and compares it to a pure W reference material. Both materials were processed via mechanical alloying (MA) and subsequent hot isostatic pressing (HIP). We performed non-standard three-point bending (TPB) tests in both an oxidising atmosphere and vacuum across a temperature range from 77 K, obtained via immersion in liquid nitrogen, to 1473 K to determine the mechanical strength, yield strength and fracture toughness. This research aims to evaluate how the mechanical behaviour of the alloy is affected by oxides formed within the material at high temperatures, primarily from 873 K, when the materials undergo a massive thermal degradation. The results indicate that the alloy is brittle to a high temperature (1473 K) under both atmospheres and that the mechanical properties degrade significantly above 873 K. We also used Vickers microhardness tests and the dynamic modulus by impulse excitation technique (IET) to determine the elastic modulus at room temperature. Moreover, we performed nanoindentation tests to determine the effect of size on the hardness and elastic modulus; however, no significant differences were found. Additionally, we calculated the relative density of the samples to assess the porosity of the alloy. Finally, we analysed the microstructure and fracture surfaces of the tested materials via field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). In this way, the relationship between the macroscopic mechanical properties and micromechanisms of failure could be determined based on the temperature and oxides forme

Primordial black holes and gravitational waves from dissipation during inflation

We study the generation of a localized peak in the primordial spectrum of curvature perturbations from a transient dissipative phase during inflation, leading to a large population of primordial black holes. The enhancement of the power spectrum occurs due to stochastic thermal noise sourcing curvature fluctuations. We solve the stochastic system of Einstein equations for many realizations of the noise and obtain the distribution for the curvature power spectrum. We then propose a method to find its expectation value using a deterministic system of differential equations. In addition, we find a single stochastic equation whose analytic solution helps to understand the main features of the spectrum. Finally, we derive a complete expression and a numerical estimate for the energy density of the stochastic background of gravitational waves induced at second order in perturbation theory. This includes the gravitational waves induced during inflation, during the subsequent radiation epoch and their mixing. Our scenario provides a novel way of generating primordial black hole dark matter with a peaked mass distribution and a detectable stochastic background of gravitational waves from inflation.Comment: 48 pages, 11 figures; matches published version in JCAP; typo corrected, the rest of the paper is unchange

An annotated and updated checklist of the ophsthobranchs ((Mollusca: Gastropoda) from Spain and Portugal (including islands and archipelagos)

The present publication is a new annotated and updated checklist of the opisthobranchs (Mollusca, Gastropoda) from the Spanish and Portuguese coasts, including their Atlantic archipelagos (Azores, Madeira, Selvagens and Canary Islands). The bathyal species recorded from the continental shelf of all these areas are also included. Incorporating a review of the literature, 523 species are included on the present checklist, 23 belonging to Architectibranchia, 111 to Cephalaspidea s. s., 14 to Anaspidea, 4 to Acochlidiomorpha, 37 to Thecosomata, 7 to Gymnosomata, 43 to Sacoglossa, 3 to Umbraculoidea, 16 to Pleurobranchoidea and 265 to Nudibranchia: 127 Doridoidea, 42 Dendronotoidea, 9 Arminoidea, and 87 Aeolidoidea. The records these species have been divided into 12 geographic sectors: 1) Spanish coast on the Bay of Biscay; 2) Galicia; 3) mainland coast of Portugal; 4) Andalusian Atlantic coast; 5) Straits of Gibraltar, including Ceuta (northern Africa); 6) Andalusian Mediterranean coast, ..

Highly photostable solid-state dye lasers based on silicon-modified organic matrices

11 pages, 13 figures, 4 tables.-- PACS: 42.55.Rz; 42.60.FcWe report on the synthesis, characterization, and physical properties of modified polymeric matrices incorporating silicon atoms in their structure and doped with laser dyes. When the silicon-modified organic matrices incorporated pyrromethene 567 (PM567) and pyrromethene 597 (PM597) dyes as actual solid solutions, highly photostable laser operation with reasonable, nonoptimized efficiencies was obtained under transversal pumping at 532 nm. At a pump repetition rate of 10 Hz, the intensity of the laser emission remained at the level or above the initial lasing intensity after 100 000 pump pulses in the same position of the sample, corresponding to an estimated accumulated pump energy absorbed by the system of 518 and 1295 GJ/mol for PM567 and PM597, respectively. When the pump repetition rate was increased to 30 Hz, the laser emission of dye PM567 decreased steadily and the output energy fell to one-half its initial value after an accumulated pump energy of 989 GJ/mol. Dye PM597 demonstrated a remarkable photostability, and under 30 Hz pumping the laser emission from some samples remained stable after 700 000 pump pulses in the same position of the sample, corresponding to an accumulated pump energy of 17 300 GJ/mol. Narrow linewidth operation with tuning ranges of up to 31 nm was obtained with both pyrromethene dyes when some of the samples were incorporated into a grazing-incidence grating oscillator.This work was supported by Project Nos. 7N/0100/02 of the Comunidad Autónoma de Madrid ( CAM) and MAT2004- 04643-C03-01 of the Spanish CICYT. One of the authors (O.G.) thanks the MEC for awarding her a Ramón y Cajal scientific contract. Another author (D.A.) thanks CAM for a predoctoral scholarship.Peer reviewe

Identification of differentially expressed key genes of Longissimus lumborum samples from Portuguese Alentejano and Bísaro local pig breeds

Most of the swine industry nowadays is about productive and profitable fast-growing lean breeds raised under intensive conditions leading to meat and fat rich in saturated fatty acids. The Portuguese local Alentejano (AL) and Bísaro (BI) pig breeds present high intramuscular fat (IMF) content which contributes to highly appreciated pork products. These breeds have different ancestors: AL belongs to the Iberian group, presenting lower growth rates and higher lipid accretion and unsaturated fatty acids level when compared to BI, which belongs to the Celtic group, sharing ancestors with leaner breeds such as Large White and Landrace. The goal of this work was to compare the muscle gene expression profiles of AL and BI pig breeds to better understand the influence of the genetic background in the main metabolic processes occurring in the Longissimus lumborum (LL) muscle, namely in terms of lipid synthesis, muscle tissue formation, protein synthesis and cell proliferation. LL samples were obtained at slaughter, from adult AL and BI pigs with ~150kg body weight. Total RNA was extracted and sequenced for a transcriptome comparison analysis. A total of 250 genes were found to be differentially expressed (DE) in LL samples (q<0.05) conditional on breed, with 174 DE genes up-regulated in AL (log2(fold_change) = 0.65 to 7.03) and 76 in BI (log2(fold_change) = 0.63 to 4.53). Genes related to skeletal muscle development and function, such as MYH3, MYH13 or ACTN4, were significantly up-regulated in BI when compared to AL, which is in agreement with the higher muscle mass of the former breed. Genes involved in lipid metabolism were up-regulated in AL, including SCD (q=0.05), responsible for catalysing the reaction that introduces the first double bond into saturated fatty acyl-CoA substrates, which agrees with the higher unsaturation of fat tissues generally associated with the former breed. A functional enrichment analysis (metabolic pathways and GO enrichment) was performed for the DE genes and the identified functions included tissue development, cellular growth and proliferation, quantity of connective tissue and lipid metabolism. Potential regulators found that explain the observed gene expression changes in the dataset included molecules such as: ADORA2A, CEBPA, SMAD3 and PPARG (predicted to be activated in AL); HDAC and ASXL1 (predicted to be inhibited in AL)

Deporte en el éter: las emisiones deportivas de Radio Nacional de España en los inicios del franquismo

Esta investigación analiza -a partir de diferentes tipos de documentación- los rastros de las emisiones deportivas de Radio Nacional de España durante el primer franquismo. Se identifican las guías de actuación que siguió Radio Nacional de España en sus emisiones deportivas como voz oficial del Estado durante el primer franquismo. En el análisis de esta documentación se advierten los propósitos de los dirigentes, los problemas a los que el ente estatal de radio tuvo que hace frente y -se apuntan- los objetivos de estas emisiones. Las conclusiones señalan dos niveles en las emisiones deportivas de Radio Nacional de España. Por un lado, su rol de catalizador de los anhelos ideológicos y políticos de la dictadura y, por otro lado, canalizar una vía de entretenimiento y ocio para las clases populares durante este periodo

La gestión de la comunicación en el ciclismo profesional. El caso de la Vuelta a Asturias

This research analyzes the communication management of the Vuelta a Asturias, one of the oldest cycling competitions on the Spanish calendar, included in the UCI Europe Tour 2.1 category. The study describesthe information management of both the specialized press and cycling teams and organization. A triangulation of methods was carried out, based on a bibliographic review, to carry out a content analysis of the information published in El Comercio, La Nueva España, Marca and Ciclismo a Fondo during the days before and during the 2021 edition. The results of these first two phases were used to carry out aseries of interviews with communication professionals in charge of organizing and disseminating the As-turian test. In this way, it has been possible to describe, on the one hand, how the communication management is from the cycling teams themselves and the organization of the event, and on the other, how the coverage of this event is carried out by the journalists in charge of these specialized tasks. A rapid andprogressive application of new technologies by journalists and communication departments, a creative process of information disintermediation by cycling teams, the importance of generating identification processes and sports sponsorship as a key piece of information were detectedEsta investigación analiza la gestión comunicativa de la Vuelta a Asturias, una de las competiciones ciclistas más antiguas del calendario español, incluida en la categoría UCI Europe Tour 2.1. El estudio describe la gestión informativa tanto de la prensa especializada como de equipos ciclistas y organización. Se realizó una triangulación de métodos, partiendo de una revisión bibliográfica, para efectuar a continuación un análisis de contenido de las informaciones publicadas en El Comercio, La Nueva España, Marca y Ciclismo a Fondo durante los días previos y el transcurso de la edición de 2021. Los resultados de estas dos primeras fases sirvieron para realizar una serie de entrevistas a profesionales dela comunicación encargados de la organización y difusión de la prueba asturiana. De este modo, se ha podido describir, por un lado, cómo es la gestión de la comunicación desde los propios equipos ciclistas y la organización de la prueba, y por otro, cómo se realiza la cobertura de este evento por parte de los periodistas encargados de estas labores especializadas. Se detectó una aplicación rápida y progresiva de las nuevas tecnologías por parte de periodistas y departamentos de comunicación, un creativo proceso dedesintermediación informativa por parte de los equipos ciclistas, la importancia de generar procesos de identificación y el patrocinio deportivo como pieza informativa clave