Simulating Turing Machines with Polarizationless P Systems with Active Membranes

We prove that every single-tape deterministic Turing machine working in t(n) t(n) time, for some function t:N→N t:N→N , can be simulated by a uniform family of polarizationless P systems with active membranes. Moreover, this is done without significant slowdown in the working time. Furthermore, if logt(n) log⁡t(n) is space constructible, then the members of the uniform family can be constructed by a family machine that uses O(logt(n)) O(log⁡t(n)) space.Ministerio de Economía y Competitividad TIN2012-3743

Large characteristically simple sections of finite groups

In this paper we prove that if G is a group for which there are k non-Frattini chief factors isomorphic to a characteristically simple group A, then G has a normal section C/R that is the direct product of k minimal normal subgroups of G/R isomorphic to A. This is a significant extension of the notion of crown for isomorphic chief factors

Bounds on the number of maximal subgroups of finite groups: applications

The determination of bounds for the number of maximal subgroups of a given index in a finite group is relevant to estimate the number of random elements needed to generate a group with a given probability. In this paper, we obtain new bounds for the number of maximal subgroups of a given index in a finite group and we pin-point the universal constants that appear in some results in the literature related to the number of maximal subgroups of a finite group with a given index. This allows us to compare properly our bounds with some of the known bounds

Los procesos formativos en el desarrollo de competencias del técnico superior universitario, bajo un modelo de educación humanista. un estudio de caso

Esta tesis es sobre los procesos formativos en el Técnico Superior Universitario (TSU). Se trata de una investigación cualitativa inmersa en un marco interpretativo con enfoque fenomenológico - fenomenográfico, que intenta comprender cómo son los procesos formativos en la trayectoria universitaria de los estudiantes de las carreras de corta duración, bajo un modelo de educación humanista. Se trata de una investigación que recupera la voz de tres principales actores: profesores, estudiantes y empleadores, sobre las experiencias vividas en torno a los procesos de enseñanza y aprendizaje.ITESO, A. C

Towards defining the role of glycans as hardware in information storage and transfer: Basic principles, experimental approaches and recent progress

The term `code' in biological information transfer appears to be tightly and hitherto exclusively connected with the genetic code based on nucleotides and translated into functional activities via proteins. However, the recent appreciation of the enormous coding capacity of oligosaccharide chains of natural glycoconjugates has spurred to give heed to a new concept: versatile glycan assembly by the genetically encoded glycosyltransferases endows cells with a probably not yet fully catalogued array of meaningful messages. Enciphered by sugar receptors such as endogenous lectins the information of code words established by a series of covalently linked monosaccharides as fetters for example guides correct intra- and intercellular routing of glycoproteins, modulates cell proliferation or migration and mediates cell adhesion. Evidently, the elucidation of the structural frameworks and the recognition strategies within the operation of the sugar code poses a fascinating conundrum. The far-reaching impact of this recognition mode on the level of cells, tissues and organs has fueled vigorous investigations to probe the subtleties of protein-carbohydrate interactions. This review presents information on the necessarily concerted approach using X-ray crystallography, molecular modeling, nuclear magnetic resonance spectroscopy, thermodynamic analysis and engineered ligands and receptors. This part of the treatise is flanked by exemplarily chosen insights made possible by these techniques. Copyright (C) 2001 S. Karger AG, Basel

La seca de encinas y alcornoques en Andalucía : decaimiento y enfermedad

El decaimiento forestal es una enfermedad de etiología compleja, resultado de la acción de un número variable de factores bióticos y abióticos que causan un deterioro gradual y general de los árboles afectados, hasta su muerte. Los factores implicados en el decaimiento de los Quercus en Andalucía son factores predisponentes de tipo selvícola, alteraciones climáticas como factor incitante, y plagas y enfermedades como factores contribuyentes. Entre las enfermedades implicadas en Seca de los Quercus destacan, por orden de importancia, la podredumbre radical causada por Phytophthora cinnamomi, los chancros de tronco y ramas causados por Botryosphaeria spp. y el chancro carbonoso causado por Biscogniauxia mediterranea. No obstante, las dos primeras enfermedades tienen una especial incidencia en distintas zonas de Andalucía de forma independiente, no asociadas al decaimiento. En el presente artículo se exponen las medidas de control disponibles contra estas enfermedades de los Quercus y se plantea la necesidad de disponer de un diagnóstico preciso en cada caso para abordar dicho control con garantías, ya que no cabe encontrar soluciones únicas que resulten eficaces con independencia de la naturaleza del problema._____________________________________The forestry decline is a complex disease, as a result of the action of a changeable number of biotic and abiotic factors that cause a gradual and general deterioration of the affected trees, until their death. The factors involved in the Quercus decline in Andalusia are predisposing factors like silvic, climatic alterations as inciting factor, and insect pest and diseases as contributing factors. Between the diseases involved in oak decline stand out, in order of importance, the root roting caused by Phytophthora cinnamomi, the chancres of trunk and branches caused by Botryosphaeria spp. and the charcoal canker caused by Biscogniauxia mediterranea. Nevertheless, the first two diseases have a special effect on different zones of Andalusia in different ways, not associated with the decay. In this article we expose the available tools of disease control. We emphasizes the need of having a precise diagnosis in every case to approach the control with guarantees, since there is no chance of finding only one efficient solution regardless of the nature of the problem

Additive Manufacturing with RepRap Methodology: Current Situation and Future Prospects

In February 2004, Adrian Bowyer, from the University of Bath, began an open initiative called RepRap, with the purpose of creating an open source rapid prototyping machine which, moreover, could replicate itself. This article analyzes the current status of the RepRap initiative, commenting the basic components of RepRap machines, the differences between the different 3D printers developed by the RepRap community so far, and the technical possibilities that opens this technology from the engineering point of view. In addition we propose some improvements that could be perfectly feasible in the short term. For this purpose, the assembly of a RepRap Mendel Prusa was performed, but with some modifications.Mechanical Engineerin

Decision P Systems and the P =NP Conjecture

We introduce decision P systems, which are a class of P systems with symbol-objects and external output. The main result of the paper is the following: if there exists an NP–complete problem that cannot be solved in polynomial time, with respect to the input length, by a deterministic decision P system constructed in polynomial time, then P = NP. From Zandron-Ferreti-Mauri’s theorem it follows that if P = NP, then no NP–complete problem can be solved in polynomial time, with respect to the input length, by a deterministic P system with active membranes but without membrane division, constructed in polynomial time from the input. Together, these results give a characterization of P = NP in terms of deterministic P systems