All-optical 3D atomic loops generated with Bessel light fields

The propagation invariance of Bessel beams as well as their transversal structure are used to perform a comparative analysis of their effect on cold atoms for four different configurations and combinations thereof. We show that, even at temperatures for which the classical description of the atom center of mass motion is valid, the interchange of momentum, energy and orbital angular momentum between light and atoms yields efficient tools for all-optical trapping, transporting and, in general, manipulating the state of motion of cold atoms.Comment: 13 pages, 9 figure

The Level of NMDA Receptor in the Membrane Modulates Amyloid-β Association and Perforation

Alzheimer’s disease is a neurodegenerative disorder that affects mostly the elderly. The main histopathological markers are the senile plaques formed by amyloid-β peptide (Aβ) aggregates that can perforate the plasma membrane of cells, increasing the intracellular calcium levels and releasing synaptic vesicles that finally lead to a delayed synaptic failure. Several membrane proteins and lipids interact with Aβ affecting its toxicity in neurons. Here, we focus on NMDA receptors (NMDARs) as proteins that could be modulating the association and neurotoxic perforation induced by Aβ on the plasma membrane. In fact, our results showed that decreasing NMDARs, using enzymatic or siRNA approaches, increased the association of Aβ to the neurons. Furthermore, overexpression of NMDARs also resulted in an enhanced association between NMDA and Aβ. Functionally, the reduction in membrane NMDARs augmented the process of membrane perforation. On the other hand, overexpressing NMDARs had a protective effect because Aβ was now unable to cause membrane perforation, suggesting a complex relationship between Aβ and NMDARs. Because previous studies have recognized that Aβ oligomers are able to increase membrane permeability and produce amyloid pores, the present study supports the conclusion that NMDARs play a critical protective role on Aβ actions in hippocampal neurons. These results could explain the lack of correlation between brain Aβ burden and clinically observed dementia

Farmers’ perceptions towards production of Ojinegra lamb meat, an autochthonous sheep breed

Over the last two decades, in Spain there has been a growing interest in recovering and maintaining autochthonous livestock breeds. This has partly occurred because these breeds are considered essential to coping with changing socio-economic and environmental conditions. The aim of the present work is to analyze the perceptions of the farmers toward the production lamb meat from an autochthonous livestock breed in Spain. In addition, were explored the interrelationships between these perceptions and characteristics of farms as well as the farmers’ objectives. The information used was obtained from a sample of 34 lamb meat producers of an autochthone sheep breed originally from northeastern Spain. The statistical analysis performed was descriptive analysis, factor analysis and cluster analysis. The results show that breeders greatly value the positive effects of sheep breeding on rural development, which generate employment in disadvantaged areas. The cluster analysis reveals the existence of two groups of farmers with different perceptions. Moreover, results indicate that the positive perceptions of producers toward autochthonous breeds are closely related to the farmers’ objectives. Hence, public and private organization initiatives that seek to promote the development of a particular breed should account for livestock farm heterogeneity. En las dos últimas décadas se ha producido en España un creciente interés por recuperar y mantener razas de ganado autóctonas, en parte por considerarse esenciales en la adaptación a condiciones socio-económicas y ambientales cambiantes. El objetivo del trabajo es analizar las percepciones de un grupo de productores hacia la carne de cordero de una raza autóctona, relacionándolas con diferentes objetivos de los ganaderos y con características de sus explotaciones. La información empleada en el estudio se obtuvo a partir de entrevistas personales dirigidas a una muestra de 34 productores de ovino de la raza autóctona originaria del noreste de España. El análisis estadístico consistió en análisis descriptivo, factorial y cluster. Los resultados indican que los ganaderos valoran mucho el efecto positivo de la explotación de la raza sobre el desarrollo rural y la generación de empleo en zonas desfavorecidas. La segmentación realizada muestra la existencia de dos grupos de productores con percepciones diferentes hacia la raza. Además las percepciones positivas de los ganaderos hacia la raza autóctona, están muy relacionadas con los objetivos perseguidos por los ganaderos en su explotación. Es por ello que cualquier medida tomada por organizaciones públicas ó privadas que pretenda la promoción y fomento de una raza, debería tener en cuenta la heterogeneidad de las explotaciones

On special partitions of [0, 1] and lineability within families bounded variation functions

We show that there exists large algebraic structures (vector spaces, algebras, closed subspaces, etc.) formed entirely (except for 0), on one hand, by singular, nowhere monotonic functions on [0, 1] and, on the other hand, by absolutely continuous nowhere monotonic functions. Several tools, of independent interest, related to obtaining special partitions of R into uncountable collections will be provided and used. The results obtained in this note are either new or improved version of already existing ones.Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasFALSEMinisterio de Ciencia e Innovación (MICINN)Junta de AndalucíaWISS 2025 projectunpu

Landslides induced by the 2010 Chile megathrust earthquake: a comprehensive inventory and correlations with geological and seismic factors

The 2010 Mw=8.8 Maule earthquake, which occurred in the subduction contact between the Nazca and the South American tectonic plates off the coast of Chile, represents an important opportunity to improve understanding of the distribution and controls for the generation of landslides triggered by large megathrust earthquakes in subduction zones. This paper provides the analysis of the comprehensive landslide inventory for the Maule earthquake between 32.5° S and 38.5° S°. In total 1226 landslides were mapped over a total area of c.120,500 km2 , dominantly disrupted slides. The total landslide volume is c. 10.6 Mm3. The events are unevenly distributed in the study area, the majority of landslides located in the Principal Andean Cordillera and a very constrained region near the coast on the Arauco Peninsula, forming landslide clusters. Statistical analysis of our database suggests that relief and lithology are the main geological factors controlling coseismic landslides, while the seismic factor with higher correlation with landslide occurrence is the ratio between peak horizontal and peak vertical ground accelerations. The results and comparison with other seismic events elsewhere suggest that the number of landslides generated by megathrust earthquakes is lower than events triggered by shallow crustal earthquakes by at least one or two orders of magnitude, which is very important to consider in future seismic landslide hazard analysis

A new class of semiclassical wave function uniformizations

We present a new semiclassical technique which relies on replacing complicated classical manifold structure with simpler manifolds, which are then evaluated by the usual semiclassical rules. Under circumstances where the original manifold structure gives poor or useless results semiclassically the replacement manifolds can yield remarkable accuracy. We give several working examples to illustrate the theory presented here.Comment: 12 pages (incl. 12 figures

Solution and Asymptotic Behavior for a Nonlocal Coupled System of Reaction-Diffusion

This paper concerns with existence, uniqueness and asymptotic behavior of the solutions for a nonlocal coupled system of reaction-diffusion. We prove the existence and uniqueness of weak solutions by the Faedo-Galerkin method and exponential decay of solutions by the classic energy method. We improve the results obtained by Chipot-Lovato and Menezes for coupled systems. A numerical scheme is presented

Nature of the Neurotoxic Membrane Actions of Amyloid-β on Hippocampal Neurons in Alzheimer\u27s Disease

The mechanism by which amyloid-β (Aβ) produces brain dysfunction in patients with Alzheimer\u27s disease is largely unknown. According to previous studies, Aβ might share perforating properties with gramicidin, a well-accepted membrane-disrupting peptide. Therefore, we hypothesize that the key steps leading to synaptotoxicity by Aβ and gramicidin involve peptide aggregation, pore formation, and calcium dysregulation. Here, we show that Aβ and gramicidin form aggregates enriched in β-sheet structures using electron microscopy, and Thioflavin and Congo Red staining techniques. Also, we found that Aβ and gramicidin display fairly similar actions in hippocampal cell membranes, i.e. inducing Ca2+ entry and synaptoxicity characterized by the loss of synaptic proteins and a decrease in neuronal viability. These effects were not observed in a Ca2+ free solution, indicating that both Aβ and gramicidin induce neurotoxicity by a Ca2+-dependent mechanism. Using combined perforated patch clamp and imaging recordings, we found that only Aβ produced a perforation that progressed from a small (Cl−-selective pore) to a larger perforation that allowed the entry of fluorescent molecules. Therefore, based on these results, we propose that the perforation at the plasma membrane by Aβ is a dynamic process that is critical in producing neurotoxicity similar to that found in the brains of AD patients

Analycity and smoothing effect for the coupled system of equations of Korteweg - de Vries type with a single point singularity

We study that a solution of the initial value problem associated for the coupled system of equations of Korteweg - de Vries type which appears as a model to describe the strong interaction of weakly nonlinear long waves, has analyticity in time and smoothing effect up to real analyticity if the initial data only has a single point singularity at $x=0.