Estimating true evolutionary distances under the DCJ model

Motivation: Modern techniques can yield the ordering and strandedness of genes on each chromosome of a genome; such data already exists for hundreds of organisms. The evolutionary mechanisms through which the set of the genes of an organism is altered and reordered are of great interest to systematists, evolutionary biologists, comparative genomicists and biomedical researchers. Perhaps the most basic concept in this area is that of evolutionary distance between two genomes: under a given model of genomic evolution, how many events most likely took place to account for the difference between the two genomes

Information filtering via Iterative Refinement

With the explosive growth of accessible information, expecially on the Internet, evaluation-based filtering has become a crucial task. Various systems have been devised aiming to sort through large volumes of information and select what is likely to be more relevant. In this letter we analyse a new ranking method, where the reputation of information providers is determined self-consistently.Comment: 10 pages, 3 figures. Accepted for publication on Europhysics Letter

Інформаційні ресурси: нові підходи до визначення поняття

У статті окреслено нові підходи щодо визначення категорій «інформаційний ресурс», «інформаційний потенціал», їх класифікації та функцій. Зазначається, що інформаційні ресурси нині стають системотворчим фактором життєдіяльності суспільства.In the article, the author determines new approaches in defining the categories of «information resource», «information potential», their classification and functions. The information resources are considered to become the important system-forming factor of the activity of society

La familia foral y la familia castellana : memoria premiada por la Academia Matritense de Jurisprudencia y Legislación, en el concurso abierto en 20 de junio de 1862

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Enhancement of the Binding Energy of Charged Excitons in Disordered Quantum Wires

Negatively and positively charged excitons are identified in the spatially-resolved photoluminescence spectra of quantum wires. We demonstrate that charged excitons are weakly localized in disordered quantum wires. As a consequence, the enhancement of the "binding energy" of a charged exciton is caused, for a significant part, by the recoil energy transferred to the remaining charged carrier during its radiative recombination. We discover that the Coulomb correlation energy is not the sole origin of the "binding energy", in contrast to charged excitons confined in quantum dots.Comment: 4 Fig

Understanding herbivore-plant-soil feedbacks to improve grazing management on Mediterranean mountain grasslands

The surface of many European mountain grasslands is decreasing due to global change and extensive grazing stands out as a key tool for their conservation. Sound knowledge of grassland ecosystem functioning and its feedback processes is required to implement sustainable grazing management. This study aimed to understand the effect of different grazing intensities on herbivore-plant-soil feedbacks in Mediterranean mountain grasslands. We estimated spatial distribution of sheep grazing intensity using GPS technology in order to assess the effect of grazing pressure on vegetation and soil properties measured throughout the study area. Our results showed that grazing intensity ranged from 0.06 to 2.85 livestock units / ha, corresponding to a gradient of pasture utilisation rates varying from 2.38% to 45.60% of annual productivity from pasture. Increasing grazing pressure was associated with smaller relative cover and species richness of non-leguminous forbs, while the opposite trends were observed for graminoids. Forage had a greater concentration of N and smaller C:N ratio in more heavily grazed areas. Increasing grazing intensity was also associated with higher values of total soil N, NO3-, NH4+, soil organic carbon, microbial biomass C and activity of ß-glucosidase. Higher litter quality was the main factor explaining greater content of soil organic matter, which favoured both soil microbes and plant productivity. Grazing induced changes in the plant community triggered positive hervibore-plant-soil feedbacks, as they ultimately improved forage quality and productivity, which significantly influenced the pasture preference of free-ranging domestic grazers. Our work showed that grazing management aiming pasture utilisation rates of around 45% is critical in sustaining positive herbivore-plant-soil feedbacks and preserving or enhancing the whole ecosystem functioning in the Mediterranean mountain grasslands studied. © 2021 The Author

Valdés Leal : estudio crítico

Copia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 202

Consideraciones críticas sobre las legítimas : memoria leída en la Real Academia de Jurisprudencia y Legislación, en sesión pública de 7 de noviembre de 1879

Copia Digital : Real Academia de Jurisprudencia y Legislación, 2011Dedicatoria autógrafa del autor a la Real Academia de Jurisprudencia y Legislació

Differences between young and old university students on lexical decision task: evidence through an ex-Gaussian approach

This work compared two common variants of a lexical decision task (LDT) through two different analysis procedures: first, the classical ANOVA method, and second, by fitting the data to an ex-Gaussian distribution function. Two groups of participants (old and young university students) had to perform, blocks of go/no-go and yes/no tasks. Reaction times and error rates were much lower in the go/no-go task than in the yes/no task. Changes in the ex-Gaussian parameter related to attention were found with word frequency but not with the type of LDT tasks. These findings suggest that word frequency shows an attentional cost that is independent of age