Beta-diversity of Central European forests decreases along an elevational gradient due to the variation in local community assembly processes

Beta-diversity has been repeatedly shown to decline with increasing elevation, but the causes of this pattern remain unclear, partly because they are confounded by coincident variation in alpha- and gamma-diversity. We used 8,795 forest vegetation-plot records from the Czech National Phytosociological Database to compare the observed patterns of beta diversity to null-model expectations (beta-deviation) controlling for the effects of alpha- and gamma-diversity. We tested whether \b{eta}-diversity patterns along a 1,200 m elevation gradient exclusively depend on the effect of varying species pool size, or also on the variation of the magnitude of community assembly mechanisms determining the distribution of species across communities (e.g., environmental filtering, dispersal limitation). The null model we used is a novel extension of an existing null-model designed for presence/absence data and was specifically designed to disrupt the effect of community assembly mechanisms, while retaining some key features of observed communities such as average species richness and species abundance distribution. Analyses were replicated in ten subregions with comparable elevation ranges. Beta-diversity declined along the elevation gradient due to a decrease in gamma-diversity, which was steeper than the decrease in alpha-diversity. This pattern persisted after controlling for alpha- and gamma-diversity variation, and the results were robust when different resampling schemes and diversity metrics were used. We conclude that in temperate forests the pattern of decreasing beta-diversity with elevation does not exclusively depend on variation in species pool size, as has been hypothesized, but also on variation in community assembly mechanisms. The results were consistent across resampling schemes and diversity measures, thus supporting the use of vegetation plot databases for understanding...Comment: Accepted version 25 pages, 5 figures, 1 tabl

SIVIM Alpine - Database of high-mountain grasslands in the Iberian Peninsula

SIVIM Alpine (GIVD ID: EU-00-034) is a thematic database focused on vegetation plots from alpine grasslands of the Iberian Peninsula. The main aim of the database is to centralize historical and new vegetation plots of grassland-like communities above the treeline from Spanish mountains, the Pyrenees (including France and Andorra) and Serra da Estrela (Portugal). The database was registered in GIVD in December 2020, and it is currently available in EVA under semi-restricted regime. SIVIM Alpine includes both digitized relevés from the literature and unpublished data. Most of digitized relevés overlap with SIVIM (GIVD ID EU-00-004) but the header data and the geographical coordinates of SIVIM Alpine have been improved when possible. The database is routinely updated with new surveys conducted with GPS and detailed ecological data. Nowadays, SIVIM Alpine contains 6,420 vegetation plots corresponding to all phytosociological alliances described in the Iberian Peninsula for high-mountain grassland vegetation, 85% of them also classified at the association level. Plot size is available for 80% of the relevés. Plant taxonomy keeps the names provided by the original authors of the relevés, with an additional correspondence to Euro+Med and The Plant List, when possible. The database is continuously updated by revisiting the original sources. Different versions of the database have been used to vegetation analysis at national at continental scales

El envejecimiento y la muerte: un enfoque filosófico

In this essay, the author reflects on the topic of aging and its focal relation to the idea of death. The author integrates historical and scientific information and then complements a philosophical assessment. This is the aim of this essays. In the first part, the different conceptions of aging that have prevailed over time are explained, emphasizing the paradigmatic cases antagonistic as Plato and Aristotle, who would later central to the present. In the second part, a brief discussion of the concepts of longevity and aging, which finally allows him to associate the theme of old age with the idea of death from the philosophical framework is done as a question. En este ensayo, el autor reflexiona acerca del tema del envejecimiento y su relación focal con la idea de la muerte. Para este propósito integra previamente información histórica y científica, para luego culminar en la complementaria valoración filosófica, objeto del ensayo. En la primera parte se explica las distintas concepciones de la vejez que han predominado en el tiempo, destacando los casos paradigmáticos como antagónicos de Platón y Aristóteles, quienes serían la principal empresa interpretativa de posteriores versiones hasta la actualidad. En la segunda parte, se realiza en forma interrogativa un breve análisis de los conceptos de longevidad y envejecimiento, que finalmente permite asociar el tema de la vejez con la idea de la muerte desde el marco filosófico.&nbsp

El video digital como herramienta de instrucción alternativa del Manual de instrucción en el uso de bienes tecnológicos

Existe una percepción generalizada, basada fundamentalmente en la observación, que las personas al adquirir un bien tecnológico domestico, al momento de iniciar el proceso de adaptación y conocimiento del mismo a través del Manual de Instrucción escrito, mas que servir de guía, tiende a provocar confusión e incertidumbre en sus usuarios. Esta investigación pretende demostrar que existe un alto indice de personas o usuarios domésticos que desconocen el manejo de los bienes tecnológicos adquiridos, lo cual no les permite usar y manejarlas adecuadamente y lograr el maximo rendimiento. Para el consumidor domestico, la información que suministra un Manual de Instrucción, después de la compra, es sumamente importante, coma fuentes de información que guían, orientan y capacitan al usuario en el uso adecuado y correcto de los bienes tecnológicos adquiridos. Muchos de estos manuales, mas que guiar, orientar y capacitar, provocan confusión e incertidumbre en los usuarios, debido a una redacción incoherente, contenidos confusos, uso inapropiado de las ilustraciones e impresiones defectuosas. Esta confusión repercute negativamente en el mercadeo del bien tecnológico domestico, la cual afecta la promesa de utilidad, de beneficio y rendimiento. Esta situación defrauda las expectativas de sus usuarios y debilita el lazo de imagen y lealtad hacia la marca. Hoy en día existe la producción audiovisual digitalizada que presenta y combine elementos de audio, vídeo y color en una gama muy significativa, reforzando aquel adagio que dice: una imagen habla mas que mil palabras. Bajo esta premisa, se propone el uso del vídeo digital como una alternativa a los actuales manuales de instrucción escritos

Corrugated velocity patterns in the spiral galaxies: NGC 278, NGC 1058, NGC 2500 & UGC 3574

We address the study of the H α vertical velocity field in a sample of four nearly face-on galaxies using long-slit spectroscopy taken with the Intermediate dispersion Spectrograph and Imaging System (ISIS), attached to the William Herschel Telescope (WHT) at the Roque de los Muchachos Observatory (Spain). The spatial structure of the velocity vertical component shows a radial corrugated pattern with spatial scales higher or within the order of 1 kpc. The gas is mainly ionized by high-energy photons: only in some locations of NGC 278 and NGC 1058 is there some evidence of ionization by low-velocity shocks, which, in the case of NGC 278, could be due to minor mergers. The behaviour of the gas in the neighbourhood of the spiral arms fits, in the majority of the observed cases, with that predicted by the so-called hydraulic bore mechanism, where a thick magnetized disc encounters a spiral density perturbation. The results obtained show that it is difficult to explain the H α large-scale velocity field without the presence of a magnetized, thick galactic disc. Larger samples and spatial covering of the galaxy discs are needed to provide further insight into this problem.We acknowledge financial support from the Spanish Ministry of Economy and Competitiveness through grants AYA2010-17631 and AYA2013-40611-P, and from the Consejeria de Educacion y Ciencia (Junta de Andalucia) through TIC-101, TIC-4075 and TIC-114Peer Reviewe