Training-induced criticality in martensites

We propose an explanation for the self-organization towards criticality observed in martensites during the cyclic process known as `training'. The scale-free behavior originates from the interplay between the reversible phase transformation and the concurrent activity of lattice defects. The basis of the model is a continuous dynamical system on a rugged energy landscape, which in the quasi-static limit reduces to a sandpile automaton. We reproduce all the principal observations in thermally driven martensites, including power-law statistics, hysteresis shakedown, asymmetric signal shapes, and correlated disorder.Comment: 5 pages, 4 figure

Zero-temperature random-field Ising model on a bilayered Bethe lattice

Peer reviewedPublisher PD

Performance evaluation and limitations of a vision system on a reconfigurable/programmable chip

This paper presents a survey of the characteristics of a vision system implemented in a reconfigurable/programmable chip (FPGA). System limitations and performance have been evaluated in order to derive specifications and constraints for further vision system synthesis. The system hereby reported has a conventional architecture. It consists in a central microprocessor (CPU) and the necessary peripheral elements for data acquisition, data storage and communications. It has been designed to stand alone, but a link to the programming and debugging tools running in a digital host (PC) is provided. In order to alleviate the computational load of the central microprocessor, we have designed a visual co-processor in charge of the low-level image processing tasks. It operates autonomously, commanded by the CPU, as another system peripheral. The complete system, without the sensor, has been implemented in a single reconfigurable chip as a SOPC. The incorporation of a dedicated visual co-processor, with specific circuitry for low-level image processing acceleration, enhances the system throughput outperforming conventional processing schemes. However, time-multiplexing of the dedicated hardware remains a limiting factor for the achievable peak computing power. We have quantified this effect and sketched possible solutions, like replication of the specific image processing hardware. © J.UCS.This work has been partially funded by project FIT-330100-2005-162 of the Spanish Ministry of Industry, Tourism and Commerce. The work of F. J. Sánchez-Fernández is supported by a grant of the Spanish Ministry of Education and Science.Peer Reviewe

Analogs of farnesylcysteine induce apoptosis in HL-60 cells

AbstractS-Farnesyl-thioacetic acid (FTA), a competitive inhibitor of isoprenylated protein methyltransferase, potently suppressed the growth of HL-60 cells and induced apoptosis, as evidenced by the development of increased annexin-V binding, decreased binding of DNA dyes and internucleosomal DNA degradation. FTA did not impair the membrane association of ras proteins, conversely, it brought about a decrease in the proportion of ras present in the cytosolic fraction. Farnesylated molecules which are weak inhibitors of the methyltransferase also induced DNA laddering and reduced the proportion of cytosolic ras. These findings suggest that neither inhibition of isoprenylated protein methylation nor impairment of ras membrane association are essential for apoptosis induced by farnesylcysteine analogs

Construcción de un reloj de sol

El objetivo de la presente colaboración es la construcción de un reloj de Sol horizontal, utilizando GeoGebra 3D, tanto para los preliminares (astronómicos fundamentalmente y de modelo) como para la comprensión de los elementos que componen un reloj y su procedimiento de construcción. La construcción de un reloj de sol facilita el entendimiento de determinadas nociones astronómicas básicas, así como de elementos geométricos que abordaremos desde una perspectiva de tres dimensiones

Lipoma parostal de fémur: Aportación de un caso

Describimos un caso de lipoma parostal de fémur, un tumor benigno poco frecuente formado por tejido adiposo maduro en relación con el periostio. Nuestro objetivo es documentar el caso, comentando los hallazgos radiológicos, histológicos y el tratamiento y realizar una revisión bibliográfica.We describe a case of parosteal lipoma of the femur. It is an infrequent benign neoplasm composed of mature fat, intermately connected with the periosteum. Our aim is to document the case, and comment the radiological, histological findings, and treatment, and review the literature

Reparación de lesiones del cartílago articular de la rótula de conejos con injertos libres de pericondrio costal y periostio tibial: Estudio histológico comparativo

El propósito del presente, estudio experimental es comparar la capacidad condrogénica de injertos libres de pericondrio y periostio en lesiones que afectan a todo el espesor del cartílago articular rotuliano. Para ellos, se eligieron 18 conejos adolescentes de Nueva Zelanda con un peso comprendido entre los 2400 y 3600 gramos, a los que se realizó una lesión de 6 mm de diámetro y 3 mm de espesor en la superficie articular de la rótula, y se distribuyeron de modo aleatorio en tres grupos: control, tratados con injerto libre de pericondrio (PC) y tratados con injerto libre de periostio (PO). Todos los animales fueron sacrificados a las 8 semanas y las preparaciones histológicas fueron evaluadas con arreglo a una escala que concede una puntuación de 0 a 17 puntos. En el análisis estadístico, las diferencias encontradas han sido, en todos los casos, entre el control y los grupos tratados, para ninguna de las variables se ha podido demostrar diferencias estadísticamente significativas entre los grupos PC y PO.The purpose of this experimental study was to compare the chondrogenic capacity of both perichondrium and periosteal free grafts in lesions affecting all the articular chondral thickness of the patella. A total of 18 white New Zeland rabbits with a weight ranging from 2.4 to 3.6 kg were operated. A chondral lesion o f 6 mm of diameter and 3 mm in depth was performed at the articular surface on the patella. The lesion was repair with either a perichondrium (6 animals) or a periosteal free grafts (6 animals). In other 6 animals, the control group, the lesion was not repaired. All animals were killed 8 weeks after surgery. Histological studies were performed using a modified O'Discoll's scale. Statistically significant differences were found between the control group and the two groups in which the lesions were repaired, but not between lesions treated with perichondrium and periosteal grafts

On the athermal character of structural phase transitions

The significance of thermal fluctuations on nucleation in structural first-order phase transitions has been examined. The prototype case of martensitic transitions has been experimentally investigated by means of acoustic emission techniques. We propose a model based on the mean first-passage time to account for the experimental observations. Our study provides a unified framework to establish the conditions for isothermal and athermal transitions to be observed.Comment: 5 pages, 4 figures, accepted in Phys. Rev. Let

Trajectories of Symptom Dimensions in Short-Term Response to Antipsychotic Treatment in Patients with a First Episode of Non-Affective Psychosis

Background Trajectory patterns of positive, disorganized and negative dimension symptoms during antipsychotic treatment in drug-naive patients with first-episode psychosis have yet to be examined by using naturalistic data. Method This pragmatic clinical trial randomized 161 drug-naive patients with a first episode of psychosis to olanzapine, risperidone or haloperidol. Patients were assessed with the Scale for the Assessment of Negative Symptoms (SANS) and Positive Symptoms (SAPS) at baseline and at the end of weeks 1, 2, 3, 4 and 6 of antipsychotic treatment. Censored normal models of response trajectories were developed with three dimensions of the SAPS-SANS scores (positive, disorganized and negative) in order to identify the different response trajectories. Diagnosis, cannabis use, duration of untreated psychosis (DUP), smoking and antipsychotic class were examined as possible predictive variables. Results Patients were classified in five groups according to the positive dimension, three groups according to the disorganized dimension and five groups according to the negative dimension. Longer DUPs and cannabis use were associated with higher scores and poorer responses in the positive dimension. Cannabis use was associated with higher scores and poorer responses in the disorganized dimension. Only schizophrenia diagnosis was associated with higher scores and poorer responses in the negative dimension. Conclusions Our results illustrate the heterogeneity of short-term response to antipsychotics in patients with a first episode of psychosis and highlight markedly different patterns of response in the positive, disorganized and negative dimensions. DUP, cannabis use and diagnosis appeared to have a prognostic value in predicting treatment response with different implications for each dimension

Optical multi-trapping by Kinoform m-Bonacci lenses

[EN] Optical manipulation is interfacing disciplines in the micro and nanoscale, from molecular biology to quantum computation. Versatile solutions for increasingly more sophisticated technological applications require multiple traps with which to maneuver dynamically several particles in three dimensions. The axial direction is usually overlooked due to difficulties in observing particles away from an objective-lens focal plane, a normal element in optical tweezers, and in managing interparticle distances along the trapping beam propagating direction, where strong radiation pressure and shadowing effects compromise the simultaneous and stable confinement of the particles. Here, aperiodic kinoform diffractive lens based on the m-Bonacci sequence are proposed as a newtrapping strategy. This lens provides split first-order diffractive foci whose separation depends on the generalized m-golden ratio. We show the extended manipulation capabilities of a laser tweezers system generated by these lens, in which concomitant trapping of particles in different focal planes takes place. Positioning particles in the axial direction with computer-controlled distances allows dynamic three-dimensional all-optical lattices, useful in a variety of microscale and nanoscale applications. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing AgreementMinisterio de Ciencia e Innovacion (PID2019-107391RB-I00); Generalitat Valenciana (PROMETEO/2019/048); Universitat Politecnica de Valencia (PAID-01-20-25).Muñoz-Pérez, FM.; Ferrando, V.; Furlan, WD.; Monsoriu Serra, JA.; Arias-Gonzalez, JR. (2022). Optical multi-trapping by Kinoform m-Bonacci lenses. Optics Express. 30(19):34378-34384. https://doi.org/10.1364/OE.4656723437834384301