172,047 research outputs found
Estudio del caso Fandango como intermediario digital de la industria audiovisual argentina : ¿innovación o thriller?
No full textFil: Devoto Borrelli, María C.. Universidad de San Andrés. Departamento de Derecho; Argentina
Europa e Islam tra i secoli XIV e XVI - Europe and Islam Between 14th and 16th Centuries (edito marzo 2002)
No full textAn advanced global soil erodibility (K) assessment including the effects of saturated hydraulic conductivity
No full textUSLE-type models are widely used to estimate average annual soil loss at large scales, with the erodibility factor (K) being the sole component that accounts for soil's susceptibility to erosion. The factor includes the information on permeability in the equation, however, most definitions of the K factor consider the soil hydrological influence only very crudely and indirectly. Thus, the direct impact of surface runoff infiltration and drainage on soil erosion is largely neglected. The objective of this study is to incorporate soil hydraulic properties in the K factor map by merging available global-scale measured saturated hydraulic conductivity (Ksat) data with soil texture and organic carbon information into a modified K factor. To achieve this, the Wischmeier and Smith (1978) soil texture-and permeability-based equation (KWischmeier factor) was modified to include Ksat, called Kksat factor. Using the Random Forest machine learning algorithm, the KWischmeier factor and the Kksat factor were each correlated with soil and remote sensing covariates for spatial extrapolation of two independent K factor maps at 1 km spatial resolution. We noted a clear decrease in the mean value of the Kksat factor (0.023 t ha h ha-1 MJ-1 mm-1) compared to the mean value of the KWischmeier factor (0.027 t ha h ha-1 MJ-1 mm-1). The reduction in Kksat factor values was most pronounced in tropical regions reflecting the difference in soil properties (e.g., clay and iron), whereas other climate regions showed relatively minor changes in comparison to the KWischmeier factor as well as to the recent global modeling of Borrelli et al. (2017) (KGloSEM factor maps). As many studies discussed an overall overestimation of (R)USLE based erosion rates compared to measurements, this reduction in the K factor might improve modeled erosion rates in the right direction. The Kksat marks an important initial step in integrating hydraulic properties into the K factor of USLE-type models and can prove their significance in future studies
Technical Note: Determination of the metabolically active fraction of benthic foraminifera by means of Fluorescent In Situ Hybridization (FISH)
No full textBenthic foraminifera are an important component of the marine biota, but protocols for investigating their viability and metabolism are still extremely limited. Classical studies on benthic foraminifera have been based on direct counting under light microscopy. Typically, these organisms are stained with Rose Bengal, which binds proteins and other macromolecules, but does not allow discrimination between viable and recently dead organisms. The fluorescent in situ hybridization technique (FISH) represents a new and useful approach to identify living cells possessing an active metabolism. Our work is the first test of the suitability of the FISH technique, based on fluorescent probes targeting the 18S rRNA, to detect live benthic foraminifera. The protocol was applied on <I>Ammonia</I> group and Miliolids, as well as on agglutinated polythalamous (i.e., <I>Leptohalysis scottii</I> and <I>Eggerella scabra</I>) and soft-shelled monothalamous (i.e., <I>Psammophaga</I> sp. and saccamminid morphotypes) taxa. The results from FISH analyses were compared with those obtained, on the same specimens assayed with FISH, from microscopic analysis of the cytoplasm colour, presence of pigments and pseudopodial activity. Our results indicate that FISH targets only metabolically active foraminifera, and allows discerning from low to high cellular activity, validating the hypothesis that the intensity of the fluorescent signal emitted by the probe is dependent upon the physiological status of cells. These findings support the usefulness of this molecular approach as a key tool for obtaining information on the physiology of living foraminifera, both in field and experimental settings
Isocinetica: L’uso di una metodica innovativa nella riabilitazione delle patologie dell’apparato locomotore
No full text“Capitolo VIII. Materiale Epigrafico”
No full textCatalogo delle tavolette cuneiformi mesopotamiche (III-I millennio a.C.) appartenenti al Pontificio Istituto Biblico e attualmente in prestito permanente ai Musei Vaticani, preceduto da capitolo introduttivo sugli aspetti storico-culturali del materiale epigrafico trattato
Multiple solutions for a self-consistent Dirac equation in two dimensions
No full textThis paper is devoted to the variational study of an effective model for the electron transport in a graphene sample. We prove the existence of infinitely many stationary solutions for a nonlinear Dirac equation which appears in the WKB limit for the Schrödinger equation describing the semi-classical electron dynamics. The interaction term is given by a mean field, self-consistent potential which is the trace of the 3D Coulomb potential. Despite the nonlinearity being 4-homogeneous, compactness issues related to the limiting Sobolev embedding H12(Ω,C)→L4(Ω,C) are avoided, thanks to the regularization property of the operator (-Δ)-12. This also allows us to prove smoothness of the solutions. Our proof follows by direct arguments
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