ALBERT

Description: Los extranjeros autorizados en 2006-2009 a residir en España por motivos de reagrupación familiar, muestran la importancia que ha alcanzado esta forma de inmigración en el total de nuevos extranjeros empadronados. La investigación se basa en una encuesta específica a reagrupantes africanos y latinoamericanos, que también informan sobre sus familiares reagrupados, hayan utilizado, o no, las leyes de reagrupación. Africanos y latinoamericanos ofrecen dinámicas y estructuras sociodemográficas muy diferentes, a resultas, entre otras causas, de la antigüedad de sus flujos, su fecundidad, su dominio del idioma español, su nivel de instrucción, sus posibilidades de ingresos, su estructura por sexo y edad, tamaño de las familias reagrupadas, etc. Se ofrece información para los dos colectivos continentales y para los subgrupos familiares —reagrupantes, cónyuges, hijos, progenitores y otros familiares—, y se utilizan escalas del conjunto estudiado y de ámbitos territoriales —Cataluña litoral, Comunidad Valenciana, Murcia-Almería—. Los africanos concentran los aspectos estructurales más negativos —idioma español, instrucción, ingresos,…—, pero también son los que declaran intenciones más firmes y generalizadas de permanencia en España. Las conclusiones orientan sobre el futuro de estos flujos. [fr] Le nombre d’étrangers autorisés à résider en Espagne entre 2006 et 2009 pour des raisons de regroupement familial démontrent l’importance acquise par cette forme d’immigration par rapport au total des nouveaux étrangers recensés. Cette recherche est fondée sur une enquête spécifique réalisée sur des demandeurs de regroupement africains et latino-américains, qui informent aussi sur les membres de leur famille ayant été regroupés, ayant eu recours ou non aux lois sur le regroupement. Les Africains et les Latino-Américains présentent des dynamiques et des structures sociodémographiques très différentes, ce qui est dû, entre autres causes, à l’ancienneté de leur flux migratoires, à leur fécondité, à la maîtrise de la langue espagnole, au niveau d’instruction, aux possibilités de revenus, à la structure par sexe et par âge, à la dimension des familles regroupées, etc. Nous présentons des informations sur les deux collectifs continentaux et sur les sous-groupes familiaux – demandeurs de regroupement, conjoints, enfants, géniteurs et autres membres de la famille –, et nous utilisons des échelles de l’ensemble étudié et des unités territoriales – littoral de la Catalogne, Communauté Valencienne, Murcie-Almería. Les Africains concentrent les aspects structurels les plus négatifs – maîtrise de la langue espagnole, niveau d’instruction, revenus… –, mais ce sont aussi ceux qui déclarent l’intention la plus ferme et généralisée de vouloir rester en Espagne. Les conclusions servent d’orientation sur l’avenir de ces flux migratoires.

Description: A scimitar-toothed cat ( Homotherium serum ) and stag moose ( Cervalces sp.) are described from Tyson Spring Cave, Fillmore County, Minnesota. These specimens represent the first records of both species in the state, and the first record for H. serum in the Great Lakes region. Although the Cervalces specimen remains undated, it shares features with pre-Wisconsin specimens from the eastern Great Plains. The H. serum individual dates to c.  26.9 ka, when the Wisconsin ice margin was less than 60 km away. Genetic analyses support the identity of the Homotherium specimen as conspecific with Homotherium serum found in older Beringian deposits, as well as both the early divergence of tribes Homotherini and Smilodontini within Machairodontinae and the early divergence of this Machairodontinae from the lineage that produced extant cats.

Description: The study of atmospheric dispersion has become increasingly important over the last 120 years or so. Research in exposure pathways, fate of pollutants, dispersion model evaluation and validation are all reliant on experimental data. The most common atmospheric tracer compounds in use at the present time are the cyclic perfluoroalkanes and sulphur hexafluoride. These compounds are non-toxic, non-reactive and have low atmospheric background concentrations although they are recognized as greenhouse gases. This review discusses their use relative to other tracer species. A brief history of their individual analyses is included. The review then seeks to give a concise description of some representative atmospheric tracer dispersion experiments in terms of range, duration and objectives, and tracers used. Concluding remarks relating to the future use of these species are also presented. Copyright © 2011 Royal Meteorological Society

Description: Among the objectives of the upcoming space missions Tandem-L and BIOMASS, is the 3-D representation of the global forest structure via synthetic aperture radar (SAR) tomography (TomoSAR). To achieve such a goal, modern approaches suggest solving the TomoSAR inverse problems by exploiting polarimetric diversity and structural model properties of the different scattering mechanisms. This way, the related tomographic imaging problems are treated in descriptive regularization settings, applying modern non-parametric spatial spectral analysis (SSA) techniques. Nonetheless, the achievable resolution of the commonly performed SSA-based estimators highly depends on the span of the tomographic aperture; furthermore, irregular sampling and non-uniform constellations sacrifice the attainable resolution, introduce artifacts and increase ambiguity. Overcoming these drawbacks, in this paper, we address a new multi-stage iterative technique for feature-enhanced TomoSAR imaging that aggregates the virtual adaptive beamforming (VAB)-based SSA approach, with the wavelet domain thresholding (WDT) regularization framework, which we refer to as WAVAB (WDT-refined VAB). First, high resolution imagery is recovered applying the descriptive experiment design regularization (DEDR)-inspired reconstructive processing. Next, the additional resolution enhancement with suppression of artifacts is performed, via the WDT-based sparsity promoting refinement in the wavelet transform (WT) domain. Additionally, incorporation of the sum of Kronecker products (SKP) decomposition technique at the pre-processing stage, improves ground and canopy separation and allows for the utilization of different better adapted TomoSAR imaging techniques, on the ground and canopy structural components, separately. The feature enhancing capabilities of the novel robust WAVAB TomoSAR imaging technique are corroborated through the processing of airborne data of the German Aerospace Center (DLR), providing detailed volume height profiles reconstruction, as an alternative to the competing non-parametric SSA-based methods.