Multifractality of quantum wave functions in the presence of perturbations

We present a comprehensive study of the destruction of quantum multifractality in the presence of perturbations. We study diverse representative models displaying multifractality, including a pseudointegrable system, the Anderson model and a random matrix model. We apply several types of natural perturbations which can be relevant for experimental implementations. We construct an analytical theory for certain cases, and perform extensive large-scale numerical simulations in other cases. The data are analyzed through refined methods including double scaling analysis. Our results confirm the recent conjecture that multifractality breaks down following two scenarios. In the first one, multifractality is preserved unchanged below a certain characteristic length which decreases with perturbation strength. In the second one, multifractality is affected at all scales and disappears uniformly for a strong enough perturbation. Our refined analysis shows that subtle variants of these scenarios can be present in certain cases. This study could guide experimental implementations in order to observe quantum multifractality in real systems.Comment: 20 pages, 27 figure

Two scenarios for quantum multifractality breakdown

We expose two scenarios for the breakdown of quantum multifractality under the effect of perturbations. In the first scenario, multifractality survives below a certain scale of the quantum fluctuations. In the other one, the fluctuations of the wave functions are changed at every scale and each multifractal dimension smoothly goes to the ergodic value. We use as generic examples a one-dimensional dynamical system and the three-dimensional Anderson model at the metal-insulator transition. Based on our results, we conjecture that the sensitivity of quantum multifractality to perturbation is universal in the sense that it follows one of these two scenarios depending on the perturbation. We also discuss the experimental implications.Comment: 5 pages, 4 figures, minor modifications, published versio

Entanglement-screening by nonlinear resonances

We show that nonlinear resonances in a classically mixed phase space allow to define generic, strongly entangled multi-partite quantum states. The robustness of their multipartite entanglement increases with the particle number, i.e. in the semiclassical limit, for those classes of diffusive noise which assist the quantum-classical transition

Semiclassical approach to fidelity amplitude

The fidelity amplitude is a quantity of paramount importance in echo type experiments. We use semiclassical theory to study the average fidelity amplitude for quantum chaotic systems under external perturbation. We explain analytically two extreme cases: the random dynamics limit --attained approximately by strongly chaotic systems-- and the random perturbation limit, which shows a Lyapunov decay. Numerical simulations help us bridge the gap between both extreme cases.Comment: 10 pages, 9 figures. Version closest to published versio

Anomalía congénita del atlas asociada con fractura de la apófisis espinosa de C-7 : a propósito de 1 caso

Se presenta 1 paciente con un defecto congenita del arco posterior del atlas asociado con una fractura de la apólisis espinosa de C-7. La TAC, precedida de una correcta evaluación clínica, permiten diferenciar los traumatismos agudos de las anomalías congénitas en el atlas.A case of a congenital cleft of the posterior arch of the atlas associated with a fracture of the spinous process of C-7 is reported. Appropiate clinical evaluation and CT-scan study allow to differentiate acute trauma from a congenital abnormality in the atlas

Optimization and validation of a new microbial inhibition test for the detection of antimicrobial residues in living animals intended for human consumption

Even though antibiotics are necessary in livestock production, they can be harmful not only due to their toxicity, but also in view of their contribution to the emergence of antimicrobial resistance. Screening tests based on microbial growth inhibition appeared to be useful tools to prevent its entry into the food chain. They have nevertheless been traditionally carried out post mortem, leading to great economical loss and harm to the environment in case a positive sample is found. Hence, the objective was to evaluate the use of a screening test as an ante mortem alternative for the detection of antibiotic residues in meat: thus, Explorer®-Blood test was optimized and validated. After adapting the procedure for matrix preparation, the assay parameters were assessed from 344 antibiotic-free blood serum samples. Limits of Detection (LoDs) were defined by spiking blood serum with several of the most common antimicrobials used in veterinary practice. LoDs were similar to those obtained for meat and were at or below the maximum residue limits set by EU legislation for muscle. Analyses of in vivo injected samples, previously characterized by LC-MS/MS, demonstrated the method’s accuracy and proved that Explorer®-Blood can be considered a suitable alternative to conventional post mortem screening methods

Influencia de los cerrojos distales en el tratamiento de las fracturas trocantéreas estables mediante clavo gamma

Hemos tratado consecutivamente mediante clavo gamma 100 pacientes mayores de 60 años con fracturas trocantéreas estables colocando en 50 de ellas los cerrojos distales y no en las otras 50, habiéndose realizado un estudio comparativo quirúrgico y evolutivo entre ambas series con un seguimiento mínimo de 3 meses. Se han producido complicaciones operatorias en el 18% de la serie con cerrojos, todas ellas en la colocación de los mismos, y en 1 caso en la serie sin cerrojos, que obligó a la colocación de éstos. La consolidación se ha producido en todos los casos, no habiendo diferencias finales en la deambulación. No se han producido complicaciones evolutivas en la serie con cerrojos y sí en la de sin cerrojos, donde se han producido 2 fracturas en la zona externa proximal del fémur que no precisaron tratamiento adicional. Los resultados apoyan que la colocación de los cerrojos distales no es necesaria en el tratamiento con clavo gamma de las fracturas estables en la región trocantérea.One hundred consecutive patients, older than 60 years, with stable trochanteric fractures were treated with gamma nail: 50 of them with distal locking screws and the other 50 without them. We performed a prospective surgical and clinical comparative study between both groups, with a minimum follow-up of three months. Opcrative complications were found in 18% of cases in the group with distal locking, all of them during the implantation of the distal screws; and in one case in the group without distal screws, which forced its placing. Healing was always achieved, without diferences for walking ability. Complications during follow-up were not observed in the group treated with distal locking, but in the other group two proximal femoral fractures of the external cortical ocurred, although they do not need additional treatment. Our results support the hypothesis that distal locking screws are not necessary for the treatment of stable trochanteric fractures with the gamma nail

Effects of insularity on insect leaf herbivory and chemical defences in a Mediterranean oak species

Aim Research on plant–herbivore interactions has shown that islands typically have low abundances and diversity of herbivores because of barriers to dispersal, isolation and reduced land area. Islands commonly have lower levels of herbivory relative to mainland regions, and, as a consequence, insular plants should exhibit lower levels of defences than their mainland counterparts. Despite these predictions, there are significant gaps in our understanding of insularity effects on plant–herbivore interactions. For instance, most work addressing the effects of insularity on plant–herbivore interactions have compared one or a few islands with a single mainland site. In addition, studies have measured herbivory or plant defences but not both, and the influence of abiotic factors has been neglected. Location Mediterranean Basin (from Spain to Greece). Taxon Quercus ilex L. Methods We conducted a large‐scale study to investigate whether insect leaf herbivory and plant chemical defences in holm oak (Quercus ilex L.) differ between insular versus mainland populations. We further investigated mechanisms by which insularity effects on herbivory may take place by assessing the influence of defences and climatic variables on herbivory. Results We found that insular populations exhibited lower herbivory and higher defences (condensed tannins) than their mainland counterparts. Our analyses, however, suggest that these concomitant patterns of insect herbivory and plant defences were seemingly unrelated as island versus mainland differences in defences did not account for the observed pattern in herbivory. Furthermore, climatic factors did not explain insularity effects on either herbivory or plant defences. Main conclusions Overall, this study provides one of the most robust assessments to date on insularity effects on herbivory and builds towards a better understanding of the ecology and evolution of plant–insect interactions in insular ecosystems.info:eu-repo/semantics/acceptedVersio

Ejecución de la estrategia en el simulador de negocios Capstone

En este trabajo se muestran las estrategias, el análisis de las decisiones y los resultados de la gestión de una empresa de sensores en el simulador de negocios Capstone. La primera parte del trabajo abarca la teoría y la segunda sección se concentra en la planeación y ejecución de las estrategias en la empresa