A Structural Analysis of Field/Circuit Coupled Problems Based on a Generalised Circuit Element

In some applications there arises the need of a spatially distributed description of a physical quantity inside a device coupled to a circuit. Then, the in-space discretised system of partial differential equations is coupled to the system of equations describing the circuit (Modified Nodal Analysis) which yields a system of Differential Algebraic Equations (DAEs). This paper deals with the differential index analysis of such coupled systems. For that, a new generalised inductance-like element is defined. The index of the DAEs obtained from a circuit containing such an element is then related to the topological characteristics of the circuit's underlying graph. Field/circuit coupling is performed when circuits are simulated containing elements described by Maxwell's equations. The index of such systems with two different types of magnetoquasistatic formulations (A* and T-$\Omega$) is then deduced by showing that the spatial discretisations in both cases lead to an inductance-like element

Quantitative Analysis of the Effective Functional Structure in Yeast Glycolysis

Yeast glycolysis is considered the prototype of dissipative biochemical oscillators. In cellular conditions, under sinusoidal source of glucose, the activity of glycolytic enzymes can display either periodic, quasiperiodic or chaotic behavior. In order to quantify the functional connectivity for the glycolytic enzymes in dissipative conditions we have analyzed different catalytic patterns using the non-linear statistical tool of Transfer Entropy. The data were obtained by means of a yeast glycolytic model formed by three delay differential equations where the enzymatic speed functions of the irreversible stages have been explicitly considered. These enzymatic activity functions were previously modeled and tested experimentally by other different groups. In agreement with experimental conditions, the studied time series corresponded to a quasi-periodic route to chaos. The results of the analysis are three-fold: first, in addition to the classical topological structure characterized by the specific location of enzymes, substrates, products and feedback regulatory metabolites, an effective functional structure emerges in the modeled glycolytic system, which is dynamical and characterized by notable variations of the functional interactions. Second, the dynamical structure exhibits a metabolic invariant which constrains the functional attributes of the enzymes. Finally, in accordance with the classical biochemical studies, our numerical analysis reveals in a quantitative manner that the enzyme phosphofructokinase is the key-core of the metabolic system, behaving for all conditions as the main source of the effective causal flows in yeast glycolysis.Comment: Biologically improve

Euclidean N=2 Supergravity

Euclidean special geometry has recently been investigated in the context of Euclidean supersymmetric theories with vector multiplets. In the rigid case, the scalar manifold is described by affine special para-Kahler geometry while the target geometries of Euclidean vector multiplets coupled to supergravity are given by projective special para-Kahler manifolds. In this letter, we derive the Killing spinor equations of Euclidean N=2 supergravity theories coupled to vector multiplets. These equations provide the starting point for finding general supersymmetric instanton solutions.Comment: 12 pages, latex. Minor sign corrections in section

Los megaeventos y sus consecuencias urbanas. Posibles perspectivas hacia las futuras experiencias brasileñas

Partiendo de la excusa de los campeonatos deportivos de ámbito mundial previstosen Brasil para los próximos años, el presente ensayo se propone discutir el papel de losmegaeventos en la transformación social y urbanística de sus ciudades-sede, tomando comoprincipal referente los Juegos Olímpicos de Verano. A través de un abordaje histórico, y conreferencias a otros autores que se dedican al tema en cuestión, se plantea un breve repaso delconjunto de experiencias olímpicas de los últimos 20 años, de las cuales se entresacan las tendenciasque hemos observado y la relación entre la evolución de los criterios de organizaciónde dichos eventos y el modelo vigente de gestión de las ciudades. Como objetivo, se busca establecerun panorama a través del cual se puedan evaluar los posibles impactos de las próximasOlimpíadas, a saber, Londres 2012 y, más específicamente, Río de Janeiro 2016. Mientrasla capital inglesa, a pocos días de su estreno como ciudad olímpica, concluye su etapa de preparación,en la antigua capital brasileña justo se empiezan a producir ahora las divergenciasy conflictos sociales que configuran el proceso de organización de un evento de este calibre

Skew polynomial extensions over zip rings

In this article, we study the relationship between left right zip property of R and skew polynomial extension over R, using the skew versions of Armendariz rings

Chiral Symmetry restoration from the hadronic regime

We discuss recent advances on QCD chiral symmetry restoration at finite temperature, within the theoretical framework of Effective Theories. $U(3)$ Ward Identities are derived between pseudoscalar susceptibilities and quark condensates, allowing to explain the behaviour of lattice meson screening masses. Unitarized interactions and the generated $f_0(500)$ thermal state are showed to play an essential role in the description of the transition through the scalar susceptibilityComment: 10 pages, 9 figures. Proceedings of "XII Quark Confinement and the Hadron Spectrum