La secuencia malacológica de la cueva de Nerja (Málaga): excavaciones de 1982

[Resumen] Este trabajo es un avance al estudio de la malaco fauna de los niveles arqueológicos del Vestfbulo de la Cueva de Nerja (Málaga). En el describimos la estratigraffa obtenida en el sondeo efectuado en la última campaña de excavaciones de 1982 en el Vestíbulo, y estudiamos los diferentes moluscos que aparecieron, agrupándolos en cuatro conjuntos, entre los que destaca el bromatológico. Observamos grandes acumulaciones de conchas que llegan a formar auténticas capas bioclásticas, conchas que fueron utiIizadas por los habitantes de la Cueva de Nerja para su alimentación. Las culturas que aparecen representadas corresponden al Paleolftico Superior, Epipaleol1tico y Neolítico Inicial, por lo que estos moluscos están situados en el Pleistoceno Final y Holoceno Inicial. A partir de los datos obtenidos en anteriores excavaciones en otra sala de la Cueva, y de los que exponemos aquí, se puede observar una serie de variaciones ecológicas y climáticas muy significativas, fundamentalmente en la transición Pleistoceno-Holoceno.[Resumé] Dans ce travail nous présentons les premieres rèsuIta ts de l' etude de lamaIacofaune du VestibuIo de la Grotte de Nerja (Málaga). Nous y décrirons la stratigraphie obtenue dans le forage réalisé dans le Vestibulo au cours de la campagne de fouilles enteprise en 1982. Aussi nous y étudions es différents mol usques apparus et les groupant en quatre ensembles, parmi lesquels il fant signaler l'eQ. semble bromatologique. N ous avons observé de grandes accumulations de coqui Ilages qui peurent former une véritable couche bioclastique. Ces coquilles ont été employ"'ees par les habitants de la Grotte pour leur alimentation. Les cultures qui y sont représentées correspondent au Paléolithique Supérieur, Epipaléolithique et Néolithique Initial, raison par laqueLle ces molusques se situeraient au Pleistocene Final el Holocene Initial. Les données obtenues par des fouilles realisées précájelment dans une autre salle de la G ro'tte ainsi que celles qui font I'objet de notre étude, nous ont permis de constater 'une série d'importantes variations écologiques et cl imati"ques fonfamentalment lors de la transition Pleistocene - Holocen

The Effects of Inter-particle Attractions on Colloidal Sedimentation

We use a mesoscopic simulation technique to study the effect of short-ranged inter-particle attraction on the steady-state sedimentation of colloidal suspensions. Attractions increase the average sedimentation velocity $v_s$ compared to the pure hard-sphere case, and for strong enough attractions, a non-monotonic dependence on the packing fraction $\phi$ with a maximum velocity at intermediate $\phi$ is observed. Attractions also strongly enhance hydrodynamic velocity fluctuations, which show a pronounced maximum size as a function of $\phi$. These results are linked to a complex interplay between hydrodynamics and the formation and break-up of transient many-particle clusters.Comment: 4 pages 4 figure

How Peclet number affects microstructure and transient cluster aggregation in sedimenting colloidal suspensions

We study how varying the P \'eclet number (Pe) affects the steady state sedimentation of colloidal particles that interact through short-ranged attractions. By employing a hybrid molecular dynamics simulation method we demonstrate that the average sedimentation velocity changes from a non- monotonic dependence on packing fraction {\phi} at low Pe numbers, to a monotonic decrease with {\phi} at higher Pe numbers. At low Pe number the pair correlation functions are close to their equilibrium values, but as the Pe number increases, important deviations from equilibrium forms are observed. Although the attractive forces we employ are not strong enough to form permanent clusters, they do induce transient clusters whose behaviour is also affected by Pe number. In particular, clusters are more likely to fragment and less likely to aggregate at larger Pe numbers, and the probability of finding larger clusters decreases with increasing Pe number. Interestingly, the life-time of the clusters is more or less independent of Pe number in the range we study. Instead, the change in cluster distribution occurs because larger clusters are less likely to form with increasing Pe number. These results illustrate some of the subtleties that occur in the crossover from equilibrium like to purely non-equilibrium behaviour as the balance between convective and thermal forces changes.Comment: 8 page

A Pipeline for the QR Update in Digital Signal Processing

[EN] The input and output signals of a digital signal processing system can often be represented by a rectangular matrix as it is the case of the beamformer algorithm, a very useful particular algorithm that allows extraction of the original input signal once it is cleaned from noise and room reverberation. We use a version of this algorithm in which the system matrix must be factorized to solve a least squares problem. The matrix changes periodically according to the input signal sampled; therefore, the factorization needs to be recalculated as fast as possible. In this paper, we propose to use parallelism through a pipeline pattern. With our pipeline, some partial computations are advanced so that the final time required to update the factorization is highly reducedThis work was supported by the Spanish Ministry of Economy and Competitiveness under MINECO and FEDER projects TIN2014-53495-R and TEC2015-67387-C4-1-R.Dolz, MF.; Alventosa, FJ.; Alonso-Jordá, P.; Vidal Maciá, AM. (2019). A Pipeline for the QR Update in Digital Signal Processing. Computational and Mathematical Methods. 1:1-13. https://doi.org/10.1002/cmm4.1022S113

Nuevas perspectivas sobre la neolitización en la cueva de Nerja (Málaga, España): la cerámica de la sala del Vestíbulo = New perspectives on the neolithization at Cueva de Nerja (Málaga-Spain): the pottery from the Vestíbulo Hall

Se presenta un conjunto de cerámicas recuperadas en la sala del Vestíbulo de la Cueva de Nerja. Sus especiales características y la datación obtenida sobre un hueso de oveja plantean una temprana llegada a la cueva de grupos de colonos neolíticos con una cultura material difícilmente comparable con la de otros conjuntos de similar cronología. Por ello se toma en consideración la posibilidad de una vía de neolitización norteafricana. Parte del conjunto cerámico presenta numerosas afinidades con el documentado en la Cultura de las Cuevas Andaluza, por lo que parece lógico ligar la colección presentada con el proceso histórico que provoca el desarrollo de esta cultura. This paper presents a collection of ceramic fragments recovered from the Vestíbulo Hall of Nerja Cave. The special features and the radiocarbon dating obtained on a sheep bone suggest the early arrival of groups of Neolithic settlers, whose material culture is hardly comparable to other assemblages of similar chronology. Thus, an alternative Neolithization process via North Africa is considered. Part of this ceramic assemblage has significant affinities with the ones documented for the Andalusian Culture of Caves, so it seems reasonable to link Neolithic groups like this one with the historical process leading to the development of this culture

Magnetic susceptibility of insulators from first principles

We present an {\it ab initio} approach for the computation of the magnetic susceptibility $\chi$ of insulators. The approach is applied to compute $\chi$ in diamond and in solid neon using density functional theory in the local density approximation, obtaining good agreement with experimental data. In solid neon, we predict an observable dependence of $\chi$ upon pressure.Comment: Revtex, to appear in Physical Review Lette

Impact of climate change on surface stirring and transport in the Mediterranean Sea

Understanding how climate change will affect oceanic fluid transport is crucial for environmental applications and human activities. However, a synoptic characterization of the influence of climate change on mesoscale stirring and transport in the surface ocean is missing. To bridge this gap, we exploit a high-resolution, fully coupled climate model of the Mediterranean basin using a Network Theory approach. We project significant increases of horizontal stirring and kinetic energies in the next century, likely due to increments of available potential energy. The future evolution of basin-scale transport patterns hints at a rearrangement of the main hydrodynamic provinces, defined as regions of the surface ocean that are well mixed internally but with minimal cross-flow across their boundaries. This results in increased heterogeneity of province sizes and stronger mixing in their interiors. Our approach can be readily applied to other oceanic regions, providing information for the present and future marine spatial planning.En prensa3,79