Flux-cutting and flux-transport effects in type-II superconductor slabs in a parallel rotating magnetic field

The magnetic response of irreversible type-II superconductor slabs subjected to in-plane rotating magnetic field is investigated by applying the circular, elliptic, extended-elliptic, and rectangular flux-line-cutting critical-state models. Specifically, the models have been applied to explain experiments on a PbBi rotating disk in a fixed magnetic field ${\bm H}_a$, parallel to the flat surfaces. Here, we have exploited the equivalency of the experimental situation with that of a fixed disk under the action of a parallel magnetic field, rotating in the opposite sense. The effect of both the magnitude $H_a$ of the applied magnetic field and its angle of rotation $\alpha_s$ upon the magnetization of the superconductor sample is analyzed. When $H_a$ is smaller than the penetration field $H_P$, the magnetization components, parallel and perpendicular to ${\bm H_a}$, oscillate with increasing the rotation angle. On the other hand, if the magnitude of the applied field, $H_a$, is larger than $H_P$, both magnetization components become constant functions of $\alpha_s$ at large rotation angles. The evolution of the magnetic induction profiles inside the superconductor is also studied.Comment: 12 pages, 29 figure

Domain wall dynamics in an optical Kerr cavity

An anisotropic (dichroic) optical cavity containing a self-focusing Kerr medium is shown to display a bifurcation between static --Ising-- and moving --Bloch-- domain walls, the so-called nonequilibrium Ising-Bloch transition (NIB). Bloch walls can show regular or irregular temporal behaviour, in particular, bursting and spiking. These phenomena are interpreted in terms of the spatio-temporal dynamics of the extended patterns connected by the wall, which display complex dynamical behaviour as well. Domain wall interaction, including the formation of bound states is also addressed.Comment: 15 pages Tex file with 11 postscript figures. Resubmitted to Phys. Rev.

Evidences of spatial (angular) filtering of sound beams by sonic crystals

We report experimental evidences of spatial (angular) filtering of sound beams propagating through sonic crystals. We show that at specific frequencies of the incident wave the paraxial plane wave compo- nents of the beam can be efficiently transmitted through the crystal, whereas the components propagat- ing at large angles are strongly reflected or deflected (filtered out) by the crystal. The modification of the angular field distribution results in formation of sound beams of relatively high spatial quality.The work was financieall supported by Spanish Ministry of since and Innovation and European Union FEDER through projects FIS2011-29731-C02-01 and -02, Generalitat Valenciana through the procect GV/2011/2055 and the UPV through PAID-05-12.Picó Vila, R.; Pérez Arjona, I.; Sánchez Morcillo, VJ.; Staliünas, K. (2013). Evidences of spatial (angular) filtering of sound beams by sonic crystals. Applied Acoustics. 74(7):945-948. https://doi.org/10.1016/j.apacoust.2013.01.003S94594874

Discriminación fina de respuestas en palomas

de respuestas en palomas. En ambos experimentos se entrenaron a palomasa picar una tecla bajo un programa de Número Fijo Consecutivo (NFC); en elque la emisión de un número mínimo de respuestas antes de visitar el comederofue reforzada. El Experimento 1 utilizó dos requisitos de respuesta: NFC4 y NFC 8, y evaluó los efectos del orden de su presentación. Los resultadosrevelaron que las palomas que iniciaron con un NFC 4 para después cambiaral NFC 8, mostraron una mejor discriminación de la cantidad de respuestasnecesaria para obtener el reforzador que las palomas que iniciaron con lasecuencia inversa. El propósito del Experimento 2 fue probar, mediante unprograma NFC con límites inferior y superior del requisito de respuesta, unprocedimiento de aproximaciones sucesivas al requisito exacto del programa,seguido de un cambio en los valores de esa condición: para algunas palomasel cambio consistió en un incremento y para otras una reducción en el cambiaron a un número mayor de respuestas en la segunda condición. Estosdatos apoyan la tesis de que las palomas discriminan de manera diferencialentre cantidades adyacentes de elementos

Coronin Is a Component of the Endocytic Collar of Hyphae of Neurospora crassa and Is Necessary for Normal Growth and Morphogenesis

Coronin plays a major role in the organization and dynamics of actin in yeast. To investigate the role of coronin in a filamentous fungus (Neurospora crassa), we examined its subcellular localization using fluorescent proteins and the phenotypic consequences of coronin gene (crn-1) deletion in hyphal morphogenesis, Spitzenkörper behavior and endocytosis. Coronin-GFP was localized in patches, forming a subapical collar near the hyphal apex; significantly, it was absent from the apex. The subapical patches of coronin colocalized with fimbrin, Arp2/3 complex, and actin, altogether comprising the endocytic collar. Deletion of crn-1 resulted in reduced hyphal growth rates, distorted hyphal morphology, uneven wall thickness, and delayed establishment of polarity during germination; it also affected growth directionality and increased branching. The Spitzenkörper of Δcrn-1 mutant was unstable; it appeared and disappeared intermittently giving rise to periods of hyphoid-like and isotropic growth respectively. Uptake of FM4-64 in Δcrn-1 mutant indicated a partial disruption in endocytosis. These observations underscore coronin as an important component of F-actin remodeling in N. crassa. Although coronin is not essential in this fungus, its deletion influenced negatively the operation of the actin cytoskeleton involved in the orderly deployment of the apical growth apparatus, thus preventing normal hyphal growth and morphogenesis

Assessment of acute-phase protein response associated with the different pathological forms of bovine paratuberculosis

11 páginas, 1 tabla.In this study, the concentrations of two acute-phase proteins (APPs), haptoglobin (Hp) and serum amyloid A (SAA), were quantitatively assessed in serum samples from cattle naturally infected with paratuberculosis (PTB). APP profiles were compared across 190 animals classified according to the different pathological forms associated with infection: uninfected (n = 59), with focal lesions (n = 73), multifocal lesions (n = 19), and diffuse paucibacillary (n = 11) and diffuse multibacillary lesions (n = 28). Our results showed a significant increase in both APPs in infected animals compared to the control group, with differences depending on the type of lesion. Hp and SAA levels were increased significantly in all infected animals, except in cows with diffuse multibacillary lesions that showed similar values to non-infected animals. The expression pattern of both APPs was similar and negatively correlated with the antibody levels against PTB. These results indicate that the release of Hp and SAA is related to the presence of PTB lesions associated with a high cell-mediated immune response and a lower bacterial load, suggesting that the pro-inflammatory cytokines that are associated with these forms are the main stimulus for their synthesis. These molecules could show some potential to be used as putative biomarkers of PTB infection, particularly for the identification of subclinical animals showing pathological forms related to latency or resistance to the development of advanced lesions.This study was funded by grants RTI2018-099496-B-I00 from the Spanish Ministry of Science and Innovation and LE259/P18 from “Junta de Castilla y León”