8 resultados para Lapiedra martinezii


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The aim of this work was to investigate the alkaloid patterns of Lapiedra martinezii and their relation to biogeography and phenology focused in a phylogenetic comparison. Plants from 14 populations of L. martinezii, covering almost its entire distribution area, were subjected to morphological, ecological, and phytochemical analysis. Experiments for different alkaloid-type content are proposed as a new tool for analysis of plant distribution. Several plants were transplanted for weekly observation of their phenological changes, and alkaloids from different plant organs were extracted, listed, and compared. The alkaloid pattern of L. martinezii comprises 49 compounds of homolycorine, lycorine, tazettine, haemantamine, and narciclasine types. The populations located in the north and south margins of the distribution area displayed alkaloid patterns different from those of the central area. Changes in these patterns during their phenological cycle may be related to a better defence for plant reproduction. L. martinezii is an old relict plant, and it has maintained some of the more primitive morphological features and alkaloid profiles of the Mediterranean Amaryllidaceae. The variations in alkaloid content observed could be interpreted in a phylogenetic sense, and those found in their phenological changes, in an adaptive one.

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Se han estudiado las comunidades vegetales casmotiticas basifilas. presentes sobre los roquedos cálidos y secos, pertenecientes al orden Asplenietalia petrarchae Br.-Bl. & Meier 1934, en el territorio de la Comunidad Valenciana y alrededores, detectándose en el mismo los siguientes sintaxones: Alianza Asplenion petrarchae Br.-Bl. & Meier 1934, con la asociación Melico-Saturejetum fruticosae O. Bolós & Vives 1957. Alianza Teucrion buxifolii Rivas Goday 1955, con las asociaciones: Hippocrepido-Scabiosetum saxatilis (Rivas Goday 1953) O. Bolós 1957, Jasonio-Teucrietum thymifolii G. Mateo 1983, Rhamno borgiae-Teucrietum buxifolii nova y Lapiedro martinezii-Cheilanthetum velleae nova.

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El estudio de las causas de la no asistencia al trabajo es uno de los retos más importantes que tienen la Salud Ocupacional y las empresas en el país. Sorprende la poca información frente al tema y la necesidad que tenemos de esta. Es claro que el

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Peponapis bees are considered specialized pollinators of Cucurbita flowers, a genus that presents several species of economic value (squashes and pumpkins). Both genera originated in the Americas, and their diversity dispersion center is in Mexico. Ten species of Peponapis and ten species of Cucurbita (only non-domesticated species) were analyzed considering the similarity of their ecological niche characteristics with respect to climatic conditions of their occurrence areas (abiotic variables) and interactions between species (biotic variables). The similarity of climatic conditions (temperature and precipitation) was estimated through cluster analyses. The areas of potential occurrence of the most similar species were obtained through ecological niche modeling and summed with geographic information system tools. Three main clusters were obtained: one with species that shared potential occurrence areas mainly in deserts (P. pruinosa, P. timberlakei, C. digitata, C. palmata, C. foetidissima), another in moist forests (P. limitaris, P. atrata, C. lundelliana, C. o. martinezii) and a third mainly in dry forests (C. a. sororia, C. radicans, C. pedatifolia, P. azteca, P. smithi, P. crassidentata, P. utahensis). Some species with similar ecological niche presented potential shared areas that are also similar to their geographical distribution, like those occurring predominantly on deserts. However, some clustered species presented larger geographical areas, such as P. pruinosa and C. foetidissima suggesting other drivers than climatic conditions to shape their distributions. The domestication of Cucurbita and also the natural history of both genera were considered also as important factors. (C) 2011 Elsevier B.V. All rights reserved.

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El trabajo llevado a cabo por la Red Estudios Filológicos ha consistido en la revisión de las memorias de los siguientes grados: Español: lengua y literaturas; Estudios árabes e islámicos; Estudios franceses; Estudios ingleses y Filología Catalana. Se han corregido erratas evidentes, se han unificado criterios compartidos por todos los grados y se han subsanado yerros tanto de forma como de contenido con el objetivo de proceder a una solicitud de modificación de estas Memorias.

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Esta investigación analiza la producción científica presentada en los congresos de la Asociación Española de Investigación de la Comunicación con el fin de comprender su desarrollo y su estado actual. Para ello, se han analizado 715 comunicaciones con veintidós variables, entre las que se encuentran: el autor, el género, la vinculación institucional, la nacionalidad, el tipo de comunicación, la metodología empleada, la réplica de contenidos, la tipología descriptiva y la finalidad de las comunicaciones. Entre otros hallazgos, los resultados muestran una mayoría femenina en la contribución académica, pero no entre los cargos académicos de mayor rango; la preferencia de los objetos de estudio empresariales, pero no profesionales o laborales; una tendencia hacia la mayor participación de doctorandos; y una elevada concentración de la producción científica en cuanto a la temática y la distribución territorial.