177,773 research outputs found
Milán y el teatro áureo español: ¿historia o mito?
No full textSurvey of the presence of Milan in Golden Age Spanish imagery, based on the historical, economic and cultural ties, especially important in those centuries. Overview of Golden Age plays whose setting is Milan, which seems to be just the typical courtly comedy reference, presenting no tangible elements of significant relevance.Reseña de la presencia de la ciudad de Milán en el imaginario español de los Siglos de Oro, en razón de los lazos históricos, económicos y culturales especialmente vivos en la época. Panorama de las comedias áureas ambientadas en Milán, que se configura como un escenario de la típica comedia palatina, sin elementos concretos de especial relevancia
Pájaros nuevos y además colaboradores. Lope frente a la escritura en colaboración
No full textEl estudio se detiene en las razones por las que Lope de Vega no se dedicó a la escritura de comedias en colaboración, con la excepción de la pieza "Los terceros de San Francisco", cuyo coautor fue Juan Pérez de Montalbán
Chain dynamics and the simulation of electron spin resonance spectra from oriented phospholipid membranes
No full textA model previously developed for describing the dynamics of flexible alkyl chains that is based on Flory's rotational isomeric state approximation is adapted and applied to the analysis of electron spin resonance (ESR) spectra obtained from a phospholipid spin label in a macroscopically aligned phospholipid membrane, In this model, rotation around each C-C bond of the labeled alkyl chain is characterized by three inequivalent minima, with one end of the chain fixed to mimic the phospholipid headgroup, and with the dynamic effects of the nitroxide label explicitly included. This model is integrated with that for the overall rotation of the phospholipid in the mean orientational potential of the aligned membrane, and it is incorporated into the stochastic Liouville equation which describes the ESR line shape in the presence of these dynamic processes. The analysis is simplified by introducing the fact that the relatively rapid internal modes of motion can be treated by motional narrowing theory and a time scale separation can be made with respect to the much slower overall motions of the phospholipid. A series of ESR spectra from the spin label 16-PC in the lipid dimyristoylphosphatidylcholine were obtained over a range of temperatures (35-65 degrees C) in the L-alpha phase for various orientations of the normal to the bilayer plane relative to the magnetic field. Very good agreement with experiment is obtained from this model by using least squares fitting procedures for the overall motional dynamics. One finds an order parameter of [D-00(2)] that is constant throughout the phase and the perpendicular component for rotational diffusion, R-perpendicular to, that ranges from about 1-3 x 10(7)s(-1) (which corresponds to the ESR slow motional regime). Fits to the ESR spectra were also obtained from a simple but standard model wherein a single overall rotational diffusion tensor is used to describe the combined effects of internal and overall dynamics. These fits were almost as good, but they lead to a much larger R-perpendicular to approximate to 3-6 x 10(8)s(-1) and a smaller [D-00(2)] = 0.1, since these parameters now include the composite effects of both types of processes. New ESR experiments are proposed to provide more critical tests of these models
Conformational dynamics and the rotational isomeric state approximation for alkyl chains
No full textThe assumption of a timescale separation between conformational kinetics and torsional modes, implicit in the rotational isomeric state approximation, is analysed on the basis of asymptotic solutions of a multidimensional diffusion equation
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Effetti dell'abbandono della gestione forestale sull'avifauna nelle abetine miste: un caso di studio nelle Alpi Orientali
No full textCurrently, relatively large parts of Alpine forests, where management has ceased for some time, show old-growth characteristics. To explore the effects of forest abandonment, we compared species richness and composition of birds between two forested watersheds of equal size (1,040 ha): Val Tovanella, where forest management ceased around 50 years ago, and Cajada, where forests are still managed. Both watersheds are located in the Dolomites of Zoldo and are found between 500 and 2,400 m a.s.l. During the breeding season in two subsequent years (2010-2011), 10 sampling plots were used to survey bird presence. In both watersheds, listening points were located within mature r forests. The abandoned forest had higher values for several structural variables: soil nitrogen, beech proportion, tree species richness and quantity of deadwood. Furthermore, composition of the tree and ground layers differed signicantly. To test differences in bird species richness we used linear mixed models by applying the REML method. The differences in composition were computed through the application of PERMANOVA and PERMDISP. Bird species richness was higher in the managed forest (REML, P=0.013, F=7.691). Overall, the composition was signicantly different (PERMANOVA, R2=0.198, P<0.001) even with similar community dispersion (i.e., variability) among treatments (PERMDISP, P=0.153, F=2.224). Some species showed signicantly higher frequencies in the managed forest: Cuculus canorus, Dendrocopos major, and Turdus viscivorus; whereas Poecile palustris was the only species with higher frequency in the abandoned forest. Fifty years of management abandonment has led to a reduction in bird species richness and a different community composition. Nevertheless, it is likely that such a short period without management did not allow the establishment of forest structures suitable to support richer and diverse bird communities, also due to a rather abundant beech proportion in the Val Tovanella forest
Interaction of MO2++ ( M = U, Np, and Pu ) with Dicarboxylate Ligands Containing Other Donor Atoms.
No full textA quantílatitve study of the interaction ol uranyl(Vl), neptunyl(VI). and plutonyl(V) with oxydiacetate, iminodiacetate, thiodiacetate, and glutarate ligands has been carried out potentiometrically in aqueous solution with IM (Na,H)ClO4 at 20°C. Possible structures lor the varíous species present in solution are indicated on the basis ol an analysis ol the potentiometric data. The hehaviour o! the lour ligands towards the actinyl(VI) ions is discussed in terms ol their ditlerent central groups sncl their basicities. The stability constants show thst there are only minor ditlerences among the tendencies of the three actinyl(Vl) ions to form complexes wíth the ligands examined
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Reactions of 5-Sulphosalicylic acid with lanthanides(III) and thorium(IV) in aqueous solution.
No full textThe complex formation equilibria of 5-sulphosalicylic acid with lanthanide(III) and thorium(IV) ions have been studied by means of potentiometric [H+] measurements in aqueous solution at 20 °C in a 1M (Na,H)ClO4 medium. The analysis of the potentiometric data referring to pH ranges where the hydrolytic reactions of metal ions are negligible indicates the formation of chelate complexes of the type LnL and LnL23- for the rare earth ions and ThL+ for the thorium ion. The ligand behaves as chelating agent through both the deprotonated carboxylate and phenolate groups. The stability constants of the complexes are reported and discussed
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