200 research outputs found

    A new species of Armeria (Plumbaginaceae) from southern Spain with molecular and morphometric evidence on its origin

    Get PDF
    The definitive version is available at http://onlinelibrary.wiley.com/The taxonomic status of the populations of Armeria from the Horconera massif (Co´rdoba province), previously misidentified or referred to without an explicit identification, is re-examined on the basis of morphological and molecular data. A multivariate analysis indicates that they can be discriminated from morphologically and geographically close taxa using morphometric characters. According to these results, and taking into account the previous evidence that supports extensive reticulation in the genus, a new species, A. trianoi, is formally described. Molecular evidence from our previous works, in particular the nuclear ribosomal ITS sequence data, provides the frame for a discussion on the origin of the new entity. It is suggested that A. trianoi may be the result of introgression of sympatric populations of A. villosa subsp. longiaristata into a pre-existing taxon, possibly A. filicaulis var. minor presently occurring in Sierra Tejeda some 50 km apart.This work has been supported by the Spanish Dirección General de Enseñanza Superior e Investigación Científica (grant DGES PB97-1146).Peer reviewe

    Desarrollo e implementación de un algoritmo paralelo de identificación de vórtices en simulaciones DNS

    Full text link
    [ES] En este trabajo se ha desarrollado e implementado en Fortran un algoritmo en paralelo para detectar y seguir la evolución temporal de los vórtices presentes en un ujo turbulento calculado mediante simulaciones DNS. Para agregar los vórtices, que son estructuras coherentes tridimensionales, el algoritmo desarrollado primero agrupa regiones coherentes bidimensionales en planos para convertirlas en nodos de un grafo. Las aristas de este grafo se sitúan entre nodos de planos consecutivos que coincidan en al menos un punto en dos dimensiones. Una vez construido el grafo el programa obtiene sus componentes conexos, y cada uno de ellos será un vórtice. Tras agregar los vórtices para una serie de pasos temporales, el programa compara las estructuras presentes en pasos temporales consecutivos, usando sus características geométricas en primer lugar y comparando punto por punto después, para así estudiar la evolución temporal de los torbellinos presentes en el campo uido. La evolución temporal de cada vórtice y sus interacciones con otros se guardan en una base de datos, desde la que se pueden representar los vórtices mediante grafos representativos de su vida e interacciones, imágenes y animaciones.[EN] In this project a parallel vortex identification and tracking algorithm has been developed and implemented in Fortran to detect and follow the evolution of vortices present in uid Fields obtained as a result of DNS simulations. To aggregate vortices, which are coherent three-dimensional structures, the developed algorithm first groups coherent regions in two-dimensions in every plane which are the nodes of a graph. This graph will has its edges between every two nodes in consecutive planes which share at least one point in two dimensions. Once the graph is built, the program groups its connected components, each being representative of a vortex. The program performs this operations for a series of time steps and then compares the structures present in pairs of consecutive time steps, first using the structures' geometric features and then performing a point to point comparison, obtaining then the evolution of the vortices present in the fluid field. The evolution of the vortices and their interactions with others are saved in a database, from which vortices can be represented by means of graphs representing their lives and interactions, images and animations.[CA] En aquest treball s'ha desenvolupat i implementat en Fortran un algoritme en paral·lel per detectar i seguir l'evolució temporal dels vórtices presents en uxos turbulents obtinguts mitjançant simulacions DNS. Per agregar els vórtices, que són estructures coherents tridimensionals, el algoritme desenvolupat primer agrupa regions coherents bidimensionals per convertir-les en els nodes d'un grafs. Les aristes d'aquest graf es situen entre els nodes de plans consecutius que coincidisquen en almenys un punt en dos dimensions. Després de construir el graf, el programa agrupa els seus components conexos, i cadascú serà un vòrtex. Després d'agregar els vórtices per una sèrie de passos temporals, el programa després compara les estructures presents en passos temporals consecutius, utilitzant les seues característiques geomètriques primer i comparat punt a punt després, per així estudiar l'evolució temporal dels vórtices presents al camp fugit. L'evolució temporal de cadascun dels vórtices i les seues interaccions amb els altres es guarden en una base de dades, des de la qual es poden representar els vórtices mitjançant grafs representatius de les vides i interaccions, imatges i animacions.Aguilar Fuertes, JJ. (2019). Desarrollo e implementación de un algoritmo paralelo de identificación de vórtices en simulaciones DNS. Universitat Politècnica de València. http://hdl.handle.net/10251/131196TFG

    Tracking Turbulent Coherent Structures by Means of Neural Networks

    Full text link
    [EN] The behaviours of individual flow structures have become a relevant matter of study in turbulent flows as the computational power to allow their study feasible has become available. Especially, high instantaneous Reynolds Stress events have been found to dominate the behaviour of the logarithmic layer. In this work, we present a viability study where two machine learning solutions are proposed to reduce the computational cost of tracking such structures in large domains. The first one is a Multi-Layer Perceptron. The second one uses Long Short-Term Memory (LSTM). Both of the methods are developed with the objective of taking the the structures' geometrical features as inputs from which to predict the structures' geometrical features in future time steps. Some of the tested Multi-Layer Perceptron architectures proved to perform better and achieve higher accuracy than the LSTM architectures tested, providing lower errors on the predictions and achieving higher accuracy in relating the structures in the consecutive time steps.This work was supported by RTI2018-102256-B-I00 of MINECO/FEDER. The computations of the new simulations were made possible by a generous grant of computing time from the Barcelona Supercomputing Centre, reference AECT-2020-2-0005.Aguilar-Fuertes, JJ.; Noguero-Rodríguez, F.; Jaen Ruiz, JC.; García-Raffi, LM.; Hoyas, S. (2021). Tracking Turbulent Coherent Structures by Means of Neural Networks. Energies. 14(4):1-15. https://doi.org/10.3390/en1404098411514

    Geoheritage as an educational resource and educational resources as heritage

    Get PDF
    El presente trabajo muestra una compilación de experiencias didácticas que emplean el patrimonio geológico como herramienta pedagógica en la enseñanza de las materias relacionadas con las Ciencias de la Tierra. El objetivo de todas ellas es acercar al alumnado al conocimiento y comprensión de los procesos que acontecen en nuestro planeta, con la finalidad de lograr un acercamiento y sensibilización hacia los mismos. Las seis propuestas seleccionadas presentan variedad en cuanto al contexto territorial de desarrollo de las actividades, a los contenidos y niveles trabajados (desde Enseñanza Secundaria hasta estudios universitarios) y a las metodologías utilizadas para la transmisión de dichos contenidos. Dentro de esta diversidad pueden distinguirse dos grupos de actividades diferentes. El primero de ellos se basa en el desarrollo de experiencias pedagógicas en localidades cuyas características geológicas resultan modélicas, únicas y/o espectaculares. Por el contrario, el segundo conjunto de actividades se centra en el trabajo de los recursos geológicos presentes en el entorno próximo del centro educativo. En ellas se explota su valor patrimonial, es decir, su potencial didáctico para abordar el estudio de la historia geológica del territorio. A través de las actividades incluidas en este compendio, se evidencia la validez de ambos tipos de aproximaciones y, al mismo tiempo, se debaten y realzan algunas de las virtudes más destacables de cada una de ellas. De esta manera, este catálogo podría resultar útil e inspirador para posibles planteamientos futuros.This manuscript presents a compilation of didactic experiences, which address the teaching of Earth Sciences through the knowledge of geological heritage. The aim of these proposals is to promote students’ comprehension of the Earth processes so that they may develop a positive attitude towards them. The six activities chosen offer a catalogue with a variety of sites, methodologies, contents and levels. Within this variety, the activities shown can be gathered into two separate groups. On the one hand, the first group collects experiences, which use geological heritage, i.e., the experiences are developed in places whose geological content is exemplary, unique and/or spectacular. On the other hand, the second group is focused on the geologic resources in the neighborhood of the school. These sites have heritage value, that is, an educational value for studying the geologic history of their territory. The activities drawn together show that both viewpoints are useful, and the benefits of each are pointed out. Consequently, this catalogue might be useful and inspiring for forthcoming attempts in this field

    The use and limits of ITS data in the analysis of intraspecific variation in Passiflora L. (Passifloraceae)

    Get PDF
    The discovery and characterization of informative intraspecific genetic markers is fundamental for evolutionary and conservation genetics studies. Here, we used nuclear ribosomal ITS sequences to access intraspecific genetic diversity in 23 species of the genus Passiflora L. Some degree of variation was detected in 21 of these. The Passiflora and Decaloba (DC.) Rchb. subgenera showed significant differences in the sizes of the two ITS regions and in GC content, which can be related to reproductive characteristics of species in these subgenera. Furthermore, clear geographical patterns in the spatial distribution of sequence types were identified in six species. The results indicate that ITS may be a useful tool for the evaluation of intraspecific genetic variation in Passiflora

    Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care : a pragmatic, randomised, non-inferiority clinical trial (OB12)

    Get PDF
    The trial was financed by Ministerio de Sanidad y Consumo Español through their call for independent clinical research, Orden Ministerial SAS/2377, 2010 (EC10-115, EC10-116, EC10-117, EC10-119, EC10-122); CAIBER—Spanish Clinical Research Network, Instituto de Salud Carlos III (ISCIII) (CAI08/010044); and Gerencia Asistencial de Atención Primaria de Madrid. This study is also supported by the Spanish Clinical Research Network (SCReN), funded by ISCIII-Subdirección General de Evaluación y Fomento de la Investigación, project number PT13/0002/0007, within the National Research Program I+D+I 2013-2016 and co-funded with European Union ERDF funds (European Regional Development Fund). This project received a grant for the translation and publication of this article from the Foundation for Biomedical Research and Innovation in Primary Care (FIIBAP) Call 2017 for grants to promote research programs.Objectives To compare the effectiveness of oral versus intramuscular (IM) vitamin B12 (VB12) in patients aged ≥65 years with VB12 deficiency. Design Pragmatic, randomised, non-inferiority, multicentre trial in 22 primary healthcare centres in Madrid (Spain). Participants 283 patients ≥65 years with VB12 deficiency were randomly assigned to oral (n=140) or IM (n=143) treatment arm. Interventions The IM arm received 1 mg VB12 on alternate days in weeks 1–2, 1 mg/week in weeks 3–8 and 1 mg/month in weeks 9–52. The oral arm received 1 mg/day in weeks 1–8 and 1 mg/week in weeks 9–52. Main outcomes Serum VB12 concentration normalisation (≥211 pg/mL) at 8, 26 and 52 weeks. Non-inferiority would be declared if the difference between arms is 10% or less. Secondary outcomes included symptoms, adverse events, adherence to treatment, quality of life, patient preferences and satisfaction. Results The follow-up period (52 weeks) was completed by 229 patients (80.9%). At week 8, the percentage of patients in each arm who achieved normal B12 levels was well above 90%; the differences in this percentage between the oral and IM arm were −0.7% (133 out of 135 vs 129 out of 130; 95% CI: −3.2 to 1.8; p>0.999) by per-protocol (PPT) analysis and 4.8% (133 out of 140 vs 129 out of 143; 95% CI: −1.3 to 10.9; p=0.124) by intention-to-treat (ITT) analysis. At week 52, the percentage of patients who achieved normal B12 levels was 73.6% in the oral arm and 80.4% in the IM arm; these differences were −6.3% (103 out of 112 vs 115 out of 117; 95% CI: −11.9 to −0.1; p=0.025) and −6.8% (103 out of 140 vs 115 out of 143; 95% CI: −16.6 to 2.9; p=0.171), respectively. Factors affecting the success rate at week 52 were age, OR=0.95 (95% CI: 0.91 to 0.99) and having reached VB12 levels ≥281 pg/mL at week 8, OR=8.1 (95% CI: 2.4 to 27.3). Under a Bayesian framework, non-inferiority probabilities (Δ>−10%) at week 52 were 0.036 (PPT) and 0.060 (ITT). Quality of life and adverse effects were comparable across groups. 83.4% of patients preferred the oral route. Conclusions Oral administration was no less effective than IM administration at 8 weeks. Although differences were found between administration routes at week 52, the probability that the differences were below the non-inferiority threshold was very low.Publisher PDFPeer reviewe
    corecore