4 research outputs found

    The role of seed dispersal, pollination and historical effects on genetic patterns of an insular plant that has lost its only seed disperser

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    Aim The genetic structure of many plant species is heavily dependent on their pollinators and seed dispersers, and can thus be altered if either of the associated mutualistic interactions is disrupted. In this study we assess the genetic diversity and structure and infer the seed/pollen gene-flow patterns among insular populations of Daphne rodriguezii, a shrub pollinated and dispersed by animals that has lost its only disperser (the lizard Podarcis lilfordi) in most of its populations. Location The island of Menorca and the islet of Colom (Balearic Islands, Western Mediterranean). Methods To assess the contribution of gene flow via pollen and seeds to the genetic structure of D.rodriguezii we used amplified fragment length polymorphisms (AFLPs; seeds and pollen) and plastid DNA sequences (cpDNA; seeds). We sampled individuals from all population nuclei of the species (12-19 adults per population): one population in Colom, where the plant-lizard interaction persists, and four in Menorca, where the seed dispersal mutualism disappeared with the extinction of the lizard. Results The highest heterozygosity values were found in Colom and in its closest population (Favàritx), whereas values were lower in the smallest Menorcan populations, which also had higher relatedness among individuals. We found distinct genetic signals between AFLP and cpDNA analyses. While AFLP markers showed low differentiation between populations, cpDNA showed a clear differentiation between them. Main conclusions Our results point to negative impacts of the disperser loss on genetic diversity and relatedness in the smaller and more isolated populations. They also suggest an old isolation by seeds, probably occurring well before the extinction of the lizard (c.2000years ago). Gene flow was maintained via pollination; however, the seed disperser loss may ultimately hinder pollinator-mediated gene flow, as a result of reduced probabilities of effective pollination among increasingly distant and scarce individuals. © 2012 Blackwell Publishing Ltd.The study was partially financed by projects BOS2011-0610 and GL2004-04884-C02-01/BOS from the Spanish Government and by a satellite project from the Consell Insular de Menorca (LIFE 2000 NAT/E/7355) financed to A.T., and by grant FP-2001-1819 (Dirección General de Investigación Científica y Técnica, Ministerio de Educación y Ciencia) to J.R.P. G.V.-A. is currently supported by a postdoctoral fellowship from the Portuguese Fundaçao para a Ciência e a Tecnologia (FCT) (Ref: SFRH/BPD/74834/2010). M.C.-C. was supported by an Isidro Parga Pondal contract (Xunta de Galicia)Peer Reviewe

    Modelos de administración y gestión, políticas y metodologías, en materia de e-learning para la enseñanza en la universidad pública española

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    Proyecto elaborado en el ámbito de la 'III convocatoria de ayudas a la innovación educativa: convocatoria para el desarrollo y participación en proyectos de innovación educativa y mejora de la calidad docente, curso 2007-2008'No existe un modelo estándar, ni aproximaciones pedagógicas, tecnológicas u organizativas únicas al e-learning. Por ello es necesario determinar cuáles son los elementos que definen la elección de un modelo u otro para su aplicación al ámbito de la educación superior. En este sentido se ofrece una aproximación a los distintos modelos existentes de e-learning para, a continuación, realizar un estudio sobre el aprendizaje derivado del uso de estos modelos: aprendizaje significativo, aprendizaje basado en problemas, aprendizaje basado en proyectos, y aprendizaje basado en casos. Por último, se ofrece un apartado en el que se describe la situación del e-learning en la Universidad pública española, se proponen modelos de evaluación del e-learning y se dan herramientas para la acción docente y para la gestión de modelos en el ámbito universitario.MadridBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

    Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Disease∗

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    OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease
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