Applications of the Conceptual Density Functional Theory Indices to Organic Chemistry Reactivity

Indexación: Web of ScienceTheoretical reactivity indices based on the conceptual Density Functional Theory (DFT) have become a powerful tool for the semiquantitative study of organic reactivity. A large number of reactivity indices have been proposed in the literature. Herein, global quantities like the electronic chemical potential μ, the electrophilicity ω and the nucleophilicity N indices, and local condensed indices like the electrophilic and nucleophilic Parr functions, as the most relevant indices for the study of organic reactivity, are discussed.http://www.mdpi.com/1420-3049/21/6/74

A P-Lingua Programming Environment for Membrane Computing

A new programming language for membrane computing, PLingua, is developed in this paper. This language is not designed for a speci c simulator software. On the contrary, its purpose is to o er a general syntactic framework that could de ne a uni ed standard for membrane computing, covering a broad variety of models. At the present stage, P-Lingua can only handle P systems with active membranes, although the authors intend to extend it to other models in the near future. P-Lingua allows to write programs in a friendly way, as its syntax is very close to standard scienti c notation, and parameterized expressions can be used as shorthand for sets of rules. There is a built-in compiler that parses these human-style programs and generates XML documents that can be given as input to simulation tools, di erent plugins can be designed to produce speci c adequate outputs for existing simulators. Furthermore, we present in this paper an integrated development environment that plays the role of interface where P-lingua programs can be written and compiled. We also present a simulator for the class of recognizer P systems with active membranes, and we illustrate it by following the writing, compiling and simulating processes with a family of P systems solving the SAT problem.Ministerio de Educación y Ciencia TIN2006-13425Junta de Andalucía TIC-58

Spectral signatures of symmetry-breaking dynamical phase transitions

Large deviation theory provides the framework to study the probability of rare fluctuations of time-averaged observables, opening new avenues of research in nonequilibrium physics. One of the most appealing results within this context are dynamical phase transitions (DPTs), which might occur at the level of trajectories in order to maximize the probability of sustaining a rare event. While the Macroscopic Fluctuation Theory has underpinned much recent progress on the understanding of symmetry-breaking DPTs in driven diffusive systems, their microscopic characterization is still challenging. In this work we shed light on the general spectral mechanism giving rise to continuous DPTs not only for driven diffusive systems, but for any jump process in which a discrete $\mathbb{Z}_n$ symmetry is broken. By means of a symmetry-aided spectral analysis of the Doob-transformed dynamics, we provide the conditions whereby symmetry-breaking DPTs might emerge and how the different dynamical phases arise from the specific structure of the degenerate eigenvectors. We show explicitly how all symmetry-breaking features are encoded in the subleading eigenvectors of the degenerate manifold. Moreover, by partitioning configuration space into equivalence classes according to a proper order parameter, we achieve a substantial dimensional reduction which allows for the quantitative characterization of the spectral fingerprints of DPTs. We illustrate our predictions in three paradigmatic many-body systems: (i) the 1D boundary-driven weakly asymmetric exclusion process (WASEP), which exhibits a particle-hole symmetry-breaking DPT for current fluctuations, (ii) the $3$ and $4$-state Potts model, which displays discrete rotational symmetry-breaking DPT for energy fluctuations, and (iii) the closed WASEP which presents a continuous symmetry-breaking DPT to a time-crystal phase characterized by a rotating condensate

Evaluación de la severidad de la incontinencia urinaria de esfuerzo con estudios urodinámicos: un estudio comparativo para detectar deficiencia intrínseca del esfínter uretral externo

ResumenObjetivoDeterminar la sensibilidad y especificidad del punto de presión de fuga abdominal (ALPP), para evaluar la presencia de deficiencia intrínseca del esfínter (DIE) comparativamente con la presión máxima de cierre uretral (MUCP, por sus siglas en inglés), estableciendo la correlación clínico-urodinámica correspondiente.ResultadosFueron evaluadas 34 pacientes con incontinencia urinaria de esfuerzo (IUE); 17 paciente (50%) fueron diagnosticadas urodinámicamente con DIE por punto de ALPP; 9 tuvieron IUE severa mientras que sólo 2 (5.8%) lo fueron por MUCP, de las cuales una tuvo IUE severa y otra, IUE moderada. Dieciocho pacientes fueron catalogadas clínicamente como IUE severa, de las cuales 17 tuvieron DIE por ALPP entre severa y moderada (94%).ConclusionesLa evaluación urodinámica de la IUE permite establecer de manera clara la fisiopatología de una disfunción del tracto urinario inferior concomitante, con la posibilidad de objetivar la presencia de IUE con el ALPP en al menos 85% de los casos, con una sensibilidad y especificidad para diagnosticar DIE muy superior a la MUCP.AbstractAimsTo determine the sensitivity and specificity of the abdominal leak point pressure (ALPP) in order to comparatively evalúate the presence of intrinsic sphincter deficiency (ISD) with máximum urethral closure pressure (MUCP) and establish the corresponding clinical and urodynamic correlation.ResultsThirty-four patients with stress urinary incontinence (SUI) were evaluated. Seventeen of those patients (50%) were urodynamically diagnosed with ISD through ALPP and 9 of them had severe SUI. Only 2 patients were diagnosed with ISD through MUCP; one of them had severe SUI and the other presented with modérate SUI. Eighteen patients were clinically classified with severe SUI, 17 of whom had moderate to severe ISD diagnosed through ALPP (94%).ConclusionsUrodynamic evaluation of SUI made it possible to clearly establish the pathophysiology of concomitant lower urinary tract dysfunction and to objectify the presence of SUI through ALPP in at least 85% of the cases. ALPP had a much higher sensitivity and specificity for diagnosing ISD than MUCP

Bounds on the dipole moments of the tau-neutrino via the process e+e−→ννˉγe^{+}e^{-}\rightarrow \nu \bar \nu \gamma in a 331 model

We obtain limits on the anomalous magnetic and electric dipole moments of the $\nu_{\tau}$ through the reaction $e^{+}e^{-}\rightarrow \nu \bar \nu \gamma$ and in the framework of a 331 model. We consider initial-state radiation, and neglect $W$ and photon exchange diagrams. The results are based on the data reported by the L3 Collaboration at LEP, and compare favorably with the limits obtained in other models, complementing previous studies on the dipole moments.Comment: 13 pages, 4 figures, to be published in The European Physical J C. arXiv admin note: substantial text overlap with arXiv:hep-ph/060527

Limits on the Electromagnetic and Weak Dipole Moments of the Tau-Lepton in E_6 Superstring Models

We obtain limits on the electromagnetic and weak dipole moments of the tau-lepton in the framework of a Left-Right symmetric model (LRSM) and a class of $E_6$ inspired models with an additional neutral vector boson $Z_\theta$. Using as an input the data obtained by the L3 and OPAL Collaborations for the reaction $e^+e^-\to \tau^+\tau^-\gamma$, we get a stringent limit on the LRSM mixing angle $\phi$, $-1.66\times 10^{-3}< \phi<1.22\times 10^{-3}$, which in turn induces bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH Collaborations from the reaction $e^+e^-\to \tau^+\tau^-$. We also get similar bounds for the weak dipole moments of the tau lepton in the framework of $E_6$ superstring models.Comment: 18 pages, 5 figure