A method for constructing permutations, involutions and orthomorphisms with strong cryptographic properties

S-Boxes are crucial components in the design of many symmetric ciphers. To construct permutations having strong cryptographic properties is not a trivial task. In this work, we propose a new scheme based on the well-known Lai-Massey structure for generating permutations of dimension n = 2к, к 2. The main cores of our constructions are: the inversion in GF(2k), an arbitrary к-bit non-bijective function (which has no pre-image for 0) and any к-bit permutation. Combining these components with the finite field multiplication, we provide new 8-bit permutations without fixed points possessing a very good combination for nonlinearity, differential uniformity and minimum degree — (104; 6; 7) which can be described by a system of polynomial equations with degree 3. Also, we show that our approach can be used for constructing involutions and orthomorphisms with strong cryptographic properties

Psychological Flexibility With Prejudices Increases Empathy and Decreases Distress Among Adolescents: A Spanish Validation of the Acceptance and Action Questionnaire–Stigma

Empathy is an emotional response that may facilitate prosocial behavior and inhibit aggression by increasing empathic concern for others. But the vicarious experience of other’s feelings may also turn into personal distress when the person has poor regulation skills and holds stigmatizing beliefs. In thinking about the processes that may trigger the experience of personal distress or empathic concern, research on the influence of psychological flexibility and inflexibility on stigma is showing promising results. Both processes are assessed with the Acceptance and Action Questionnaire–Stigma (AAQ-S). The current study sought to carry out a validity study of a Spanish version of the AAQ-S with a sample of adolescents aged 11–17 years. The study included an expanded test of its predictive validity with measures at three times to evaluate the role of psychological flexibility and inflexibility as risk or protective variables for the development of personal distress and/or empathic concern in the stigmatizer. Statistical analyses confirmed a two-correlated-factor solution, the adequate reliability of both factors, and their construct and predictive validity in the expected direction. The stigmatizer’s inflexible reaction to their stigmatizing thoughts predicted the occurrence of personal distress, whereas the stigmatizer’s flexible reaction to their stigmatizing thoughts predicted the occurrence of empathic concern for others. These findings confirm the importance of considering the role of regulatory skills in the experience of empathic concern or personal distress in the presence of stigmatizing thoughts, with possible implications for the promotion of prosocial behavior and the reduction of aggressive behavior among adolescents.

A vision of uses and gratifications applied to the study of Internet use by adolescents

Based on uses and gratifications theory, the aim of this paper is to identify the reasons for using Internet among teenagers and to check different variables in order to predict types of uses. After conducting a representative survey applied to 397 high school students in Community of Madrid (Spain), Internet users’ gratifications and their relationships with variables related to adolescent characteristics, family context and time of online exposure are analyzed. The article concludes that daily use of Internet predicts higher consumption of communication and social relationship

How the geometry of the scan body affects the accuracy of digital impressions in implant supported prosthesis. In vitro study

To determine and compare how three-dimensionally accurate scan bodies of different geometric shapes are placed over 6 implants (platform or crestal module). A master plaster model was made with 6 INHEX STD implant analogs made by Mozo-Grau S.A and 4 sc

Phase diagram of the (bosonic) Double-Exchange Model

The phase diagram of the simplest approximation to Double-Exchange systems, the bosonic Double-Exchange model with antiferromagnetic super-exchange coupling, is fully worked out by means of Monte Carlo simulations, large-N expansions and Variational Mean-Field calculations. We find a rich phase diagram, with no first-order phase transitions. The most surprising finding is the existence of a segment like ordered phase at low temperature for intermediate AFM coupling which cannot be detected in neutron-scattering experiments. This is signaled by a maximum (a cusp) in the specific heat. Below the phase-transition, only short-range ordering would be found in neutron-scattering. Researchers looking for a Quantum Critical Point in manganites should be wary of this possibility. Finite-Size Scaling estimates of critical exponents are presented, although large scaling corrections are present in the reachable lattice sizes.Comment: 17 pages, 14 figure

Modulador acusto-óptico en amplitud de fibra óptica basado en ondas acústicas de flexión

Se reporta un estudio experimental de la operación de un modulador acusto-óptico (MAO) de fibra óptica basado en la interacción acusto-óptica producida por ondas acústicas de flexión estacionarias. Concentramos nuestra atención en los efectos de reducir el diámetro en la fibra óptica como mecanismo para optimizar la respuesta espectral del MAO. Como caso particular reportamos un modulador de 70 ¹m de diametro con una alta profundidad de modulación (60 %), bajas perdidas por inserción (1.3 dB) y un ancho ancho de banda a 3 dB de 40 nm que opera en el rango de los megahertz. Los resultados obtenidos demuestran que el incluir fibras estrechadas se puede considerar como un grado extra de libertad en el diseño del modulador para controlar el ancho de banda.An experimental study of an in-fiber acousto-optic modulator (AOM) based on the acousto-optic interaction produced by standing flexural acoustic waves is reported. We focus our attention in the effects of a gradual reduction in the optical fiber as the mechanisms to improve the spectral response of the AOM. As a particular case we report a 70-μm fiber AOM. Our approach permits the implementation of high modulation depth (60 %), low optical loss (1.3 dB) and a 3 dB broad modulation bandwidth of 40 nm, operating in the MHz frequency range. The experimental results demonstrate that including tapered optical fibers can be regarded as an extra degree of freedom to control the optical bandwidth of the modulator.Fil: Bello Jiménez, M. A.. Instituto de Investigacion en Comunicación Optica, Universidad Autónoma de San Luis Potosí; MéxicoFil: Cuadrado Laborde, Christian Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Diez, Antonio. Universidad de Valencia; EspañaFil: Cruz, Jose Luis. Universidad de Valencia; EspañaFil: Andres Bou, Miguel. Universidad de Valencia; Españ

Origen y desarrollo del totalitarismo en el Estado moderno

A lo largo de los dos últimos siglos se han contemplado distintas formas de gobierno. Democracias, dictaduras militares y totalitarismos han tenido lugar, de manera incluso simultánea, en Europa y han mostrado diferentes interpretaciones que la época Moderna hace sobre el poder y el Estado. El presente ensayo busca analizar qué se entiende por movimiento totalitario, cómo surge una administración con estas características y cuáles son sus implicaciones en la vida pública de la sociedad en la que se desarrolla. Es decir, estudiar cómo es posible que una forma de gobierno que promueve la alienación del ser humano logre alcanzar el poder en un periodo que se dice moderno. El totalitarismo surge por un deterioro en el sistema político. Por ello es relevante analizar cuáles han sido los pasos que han hecho viable la aparición de partidos políticos que ansíen la dominación total. Esta cuestión ha sido abordada por distintos autores que han analizado, sin lugar a duda, de forma brillante y exhaustiva la forma de gobierno totalitaria. En particular destaca el trabajo de Hannah Arendt recogido en su obra El origen de los totalitarismos y de William Ebenstein, en su título El totalitarismo. También es preciso mencionar las investigaciones de Raymond Aron y Franz Neumann, ya que sus indagaciones permiten encuadrar el fenómeno del totalitarismo en el contexto político en el que surgen. Proporcionan un análisis sobre la situación de las formas de gobierno anteriores al ascenso de los movimientos totalitarios que se vuelve necesario para entender la raíz de esta forma de gobierno. El objetivo de este escrito persigue analizar las condiciones de posibilidad del partido totalitario, su ascenso al poder y los elementos que lo componen y le permiten mantener el control de la sociedad. Ciertamente es digno de estudio que una fórmula de gobierno basada en la represión de la población en su conjunto perdure en una posición de mando. Para ello, la metodología que se mantiene a lo largo de la investigación pretende recorrer la trayectoria que tienen los postulados totalitarios desde el momento en el que se hace posible su génesis, a saber, en el cambio de paradigma que la Modernidad trae consigo en el concepto del poder político. En este sentido, debe considerarse, en primer lugar, la lectura que la política moderna hace sobre el ser humano, la utilidad de las agrupaciones políticas y los objetivos Eduardo Jiménez Zorita 2 que persigue el Estado. Las administraciones modernas manifiestan una extremada complejidad en su forma, con un gran entramado burocrático; pero una enorme facilidad para ser dominadas por agrupaciones absolutistas. En este contexto se debe analizar el surgimiento del totalitarismo, que aparece como una fuerza revolucionaria y salvadora. A pesar de que el movimiento tiránico se presenta bajo distintas apariencias, en función de la nación en la que se desarrolla, todas ellas obedecen a una suerte de patrón que permite detectar los elementos comunes. Entonces es viable extraer y examinar los rasgos propios que presenta dicha forma de gobierno, para poder inferir las consecuencias que un régimen de este tipo produce en la política y en población a la que somete

Dynamical generation of a gauge symmetry in the Double-Exchange model

It is shown that a bosonic formulation of the double-exchange model, one of the classical models for magnetism, generates dynamically a gauge-invariant phase in a finite region of the phase diagram. We use analytical methods, Monte Carlo simulations and Finite-Size Scaling analysis. We study the transition line between that region and the paramagnetic phase. The numerical results show that this transition line belongs to the Universality Class of the Antiferromagnetic RP(2) model. The fact that one can define a Universality Class for the Antiferromagnetic RP(2) model, different from the one of the O(N) models, is puzzling and somehow contradicts naive expectations about Universality

MicroRNAs Sequencing for Understanding the Genetic Regulation of Plant Genomes

MicroRNAs (miRNAs) are endogenous non-coding RNAs that play important regulatory roles in animals and plants by targeting mRNAs for cleavage or translational repression. Small RNAs are classified into different types by their biogenesis and mode of action, such as miRNAs, siRNAs, piRNAs, and snoRNAs. In the case of miRNAs, this specific type regulates gene expression in plants and animals by targeting mRNAs for cleavage and translational repression, respectively. Diverse miRNAs regulate plant development, metabolism, and responses to biotic and abiotic stresses. The identification of miRNAs has been accomplished in diverse species, organs and developmental or diverse biotic and abiotic stress conditions. Novel massive sequencing techniques and further bioinformatics analysis have allowed the identification of hundreds of miRNAs in Arabidopsis thaliana, Oryza sativa, Malus domestica, Zea mays, Solanum lycopersicum, and other plants. Functional characterization of a given miRNA in a specific biological context has shown their role in the fine-tuning mechanisms of posttranscriptional gene regulation. In this chapter, besides making a summary of genome-wide miRNA profiling in plants, we describe how gain and loss of function approaches influence plant phenotypes that affect development, physiology or stress responses, pointing to miRNAs as effective tools for the generation of new plant phenotypes that improve plant productivity and conservation