265 research outputs found
Joan Mañé: la nació i l'Estat des de la premsa
La biografia esdevĂ© un element imprescindible per entendre un temps, una societat i una manera de ser. La de Joan Mañé i Flaquer ens ajuda a cercar aquests elements en la relaciĂł i el lloc que va ocupar Catalunya dins de l’Espanya liberal. Però tambĂ© Ă©s la relectura dels mitjans de comunicaciĂł com a element de difusiĂł ideològica de primer ordre i de com es va començar a constituir en una empresa de carĂ cter capitalista, en un moment en què el debat polĂtic comença a sortir dels reduĂŻts cenacles d’una petita minoria de persones.The biography becomes an indispensable element in order to understand a time, a society and a way of being. That of Joan Mañé i Flaquer helps us to find these elements in the relationship and the position taken by Catalonia in liberal Spain. But it is also a new reading of the media as an element of ideological diffusion of the first order and how it came to transform itself into a capitalist style business, at a time when political debate was starting to spread from the previously limited circles of a small minority
Influence of temperature on high molecular weight poly(lactic acid) stereocomplex formation
The influence of temperature on the formation of high molecular weight poly(lactic acid) (PLA) stereocomplex was studied by evaluation of the precipitates from dioxane solutions of PLA enantiomers (PLLA and PDLA). The racemic mixtures were characterized by Gel Permeation Chromatography, Infrared Spectroscopy, Differential Scanning Calorimetry, Scanning Electronic Microscopy, Wide-Angle X-ray Scattering and Vicat Softening Temperature. Precipitation was carried out under different solution temperatures, keeping constant the mixing ratio (XD), the molecular weight, the optical purity of both PLA enantiomers and the stirring rate. It was found that the precipitates contained only pure stereocomplex crystallites (racemic crystallites), without observing crystal phase separation between both homocrystals. The kinetics of the insoluble phase formation could be adjusted with the Avrami model, classically used for polymer crystallization in molten state. It was observed that the maximum PLA stereocomplex production rate was at about 40°C. However, more thermally stable racemic crystallites were formed at high solution temperatures. It was found that all the precipitates were sphere-like at 10 g·dl–1 at the solution temperature of 25, 40, 60 and 80°CPeer ReviewedPostprint (author's final draft
Plantes transgèniques en recerca
El conjunt d'aproximacions presentades en aquest article il·lustra alguns dels usos més
habituals de les plantes transgèniques en la recerca, que han permès, i encara permeten,
respondre moltes preguntes genuĂŻnes de gran interès biològic difĂcilment resolubles per
altres aproximacions. Per això es pot afirmar que les plantes transgèniques han revolucionat
la recerca bĂ sica i aplicada en el camp de la biologia vegetal. La seua utilitzaciĂł ens
estĂ ajudant a entendre millor com uns organismes tan fascinants i plĂ stics com les plantes
es formen i, en interaccionar amb el medi, responen alterant la seua forma o fisiologia.
Encara ens queda molt per conèixer, i l'ús de plantes transgèniques en la nostra recerca
encara té molt a dir. Esbrinar més o menys depèn, en gran mesura, de la imaginació dels
investigadors.The different strategies summarized in the manuscript illustrate some of the most common
uses of transgenic plants in research. They have allowed answering several questions
of great biological importance that cannot be easily addressed by other approaches.
For that reason it is probably correct to state that transgenic plants have revolutionized
basic and applied research in plant biology. Its utilization is helping us to better understand
how these fascinating and plastic organisms are formed and, when interacting with
the environment, responding by changing their form and/or physiology. We still have a lot to learn, and usage of transgenic plants in our research still has a lot to give. To discover
more or less depends, partially, on the imagination of researchers
Euphorbia duvalii Lecoq & Lamotte en la penĂnsula ibĂ©rica
Euphorbia duvalii Lecoq & Lamotte is an endemic species from the Catalan-Occitan territory -western Mediterranean area- and is usually found in the south of France. Euphorbia duvalii has been cited from some localities of the Iberian Peninsula, but in later reviews all of these citations were finally identified as other species of Euphorbia L. One of these citations, from the Alt EmpordĂ -Girona, Spain-, was of specific interest because not all the sources agreed on what the species was. To clarify whether or not this species is really present in the Iberian Peninsula, we examined new material from this population in order to establish whether the species is in fact E. duvalii. Once the morphology of the specimens from the Serra de Bac Grillera population had been analysed, we were able to confirm that they were indeed E. duvalii. This means that this is the only area on the Iberian Peninsula where this endemic species has been identified. The population is located in a rocky meadow that contains some scrub and is surrounded by pinewoods. Because this is the one and only Iberian population, a management and conservation plan needs to be drawn up to ensure its preservation.Euphorbia duvalii Lecoq & Lamotte es una especie endĂ©mica del territorio catalano-occitano -área mediterránea occidental- que puede ser hallada normalmente en el sur de Francia. Euphorbia duvalii ha sido citada de algunas localidades de la PenĂnsula IbĂ©rica, pero en revisiones posteriores todas las citas se identificaron finalmente como otras especies de Euphorbia L. Una de estas citas, la del Alt EmpordĂ -Gerona, España-, era muy interesante, ya que no todas las fuentes estaban de acuerdo a quĂ© especie correspondĂa. Para clarificar si esta especie se encuentra en la PenĂnsula IbĂ©rica, examinamos material nuevo de esta localidad para determinar si la especie era de hecho E. duvalii. Tras el análisis de la morfologĂa de los especĂmenes de la poblaciĂłn de la sierra de Bac Grillera, fuimos capaces de confirmar que se trataba de E. duvalii. Esto significa que Ă©sta es la Ăşnica área en la penĂnsula ibĂ©rica donde esta especie endĂ©mica ha sido identificada. La poblaciĂłn se encuentra en un prado rocoso con algunos matorrales y rodeado de pinares. Ya que Ă©sta es la Ăşnica poblaciĂłn ibĂ©rica, es necesario un plan de gestiĂłn y conservaciĂłn de esta especie para su preservaciĂłn
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