Electroweak quark-lepton symmetry and weak topological-charge confinement in the Standard Model with Dirac neutrinos

The standard electroweak model with Dirac neutrinos is extended by way of the principles of electroweak quark-lepton symmetry and weak topological-charge confinement to account for quark-lepton charge relations which, if not accidental, are indicative of charge structures. A mixing in quarks and leptons of underlying integer local charges with integer weak topological charges associated with an additive group Z_3, fixed by the anomaly cancellation requirement, is discussed. It is found that the electroweak difference between topological quarks and leptons is the nonequivalence between the topological vacua of their weak field configurations, produced by a four-instanton which carries the topological charge, induces the universal fractional piece of charge distinguishing quarks from leptons, and breaks the underlying symmetry. The constituent quarks of the standard model appear as coming from topological quarks, via the weak four-instanton event. Dual transitions occur for leptons. It is shown that several other fundamental problems left open in the standard electroweak model with Dirac neutrinos are solved: the one-to-one correspondence between quark and lepton flavors, the existence of three generations, the conservation and ungauging of B-L, the electric charge quantization, and the confinement of fractional electric charges.Comment: 23 pages, 1 figure, uses IJMPA.cl

Presymmetry beyond the Standard Model

We go beyond the Standard Model guided by presymmetry, the discrete electroweak quark-lepton symmetry hidden by topological effects which explain quark fractional charges as in condense matter physics. Partners of the particles of the Standard Model and the discrete symmetry associated with this partnership appear as manifestations of a residual presymmetry and its extension from matter to forces. This duplication of the spectrum of the Standard Model keeps spin and comes nondegenerated about the TeV scale.Comment: 6 pages, 11 figures. To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Regime transitions in stratified shear flows: the link between horizontal and inclined ducts

We present an analytical model that provides the transition curves between different regimes of stratified shear flows in inclined ducts for high Schmidt number values. These curves are described by constant values of a generalized Reynolds number multiplied by the aspect ratio of the duct, showing good agreement with previous experimental results. The generalized Reynolds number is obtained by extending to inclined ducts the solution of a one-dimensional model of a stratified shear flow in a horizontal duct within a regime where advection is neglected in the momentum equation but included in the density transport equation

Pattern formation of spherical particles in an oscillating flow

We study the self-organization of spherical particles in an oscillating flow through experiments inside an oscillating box. The interactions between the particles and the time-averaged (steady streaming) flow lead to the formation of either one-particle-thick chains or multiple-particle-wide bands, depending on the oscillatory conditions. Both the chains and the bands are oriented perpendicular to the direction of oscillation with a regular spacing between them. For all our experiments, this spacing is only a function of the relative particle-fluid excursion length normalized by the particle diameter, $A_r/D$, implying that it is an intrinsic quantity that is established only by the hydrodynamics. In contrast, the width of the bands depends on both $A_r/D$ and the confinement, characterized by the particle coverage fraction $\phi$. Using the relation for the chain spacing, we accurately predict the transition from one-particle-thick chains to wider bands as a function of $\phi$ and $A_r/D$. Our experimental results are complemented with numerical simulations in which the flow around the particles is fully resolved. These simulations show that the regular chain spacing arises from the balance between long-range attractive and short-range repulsive hydrodynamic interactions, caused by the vortices in the steady streaming flow. We further show that these vortices induce an additional attractive interaction at very short range when $A_r/D\gtrsim0.7$, which stabilizes the multiple-particle-wide bands. Finally, we give a comprehensive overview of the parameter space where we illustrate the different regions using our experimental data.Comment: 20 pages, 16 figures, 1 table, to be submitted to Physical Review

Mediating role of activity level in the depressive realism effect

Several classic studies have concluded that the accuracy of identifying uncontrollable situations depends heavily on depressive mood. Nondepressed participants tend to exhibit an optimistic illusion of control, whereas depressed participants tend to better detect a lack of control. Recently, we suggested that the different activity levels (measured as the probability of responding during a contingency learning task) exhibited by depressed and nondepressed individuals is partly responsible for this effect. The two studies presented in this paper provide further support for this mediational hypothesis, in which mood is the distal cause of the illusion of control operating through activity level, the proximal cause. In Study 1, the probability of responding, P(R), was found to be a mediator variable between the depressive symptoms and the judgments of control. In Study 2, we intervened directly on the mediator variable: The P(R) for both depressed and nondepressed participants was manipulated through instructions. Our results confirm that P(R) manipulation produced differences in the participants’ perceptions of uncontrollability. Importantly, the intervention on the mediator variable cancelled the effect of the distal cause; the participants’ judgments of control were no longer mood dependent when the P(R) was manipulated. This result supports the hypothesis that the so-called depressive realism effect is actually mediated by the probability of responding

Dynamics and structure of decaying shallow dipolar vortices

The current work reports on a numerical and experimental study of the evolution of decaying dipolar vortices in a shallow fluid layer. The dynamics and the structure of such vortices are investigated as a function of both their Reynolds number Re and the aspect ratio of vertical and horizontal length scales δ. By quantifying the strength of the secondary motions (vertical motions and nonzero horizontal divergence) with respect to the swirling motions of the primary vortex cores, it was found that the three-dimensionality of a shallow (δ << 1) dipolar vortex only depends on a single parameter: δ²Re. Depending on the value of this parameter, three flow regimes are observed for shallow dipolar vortices: (1) a quasi-two-dimensional regime where the structure of the dipolar vortex remains almost unchanged throughout its lifetime, (2) a transitional regime where the structure presents some three-dimensional characteristics but remains coherent, and (3) a three-dimensional regime where the structure of the dipolar vortex acquires a complicated three-dimensional shape with a persistent spanwise vortex at its front

Biological significance as a determinant of cue competition.

ABSTRACT Many researchers have noted the similarities between causal judgment in humans an

Agreement of body composition methods in elite male football referees

Objective: The current literature about the body composition of elite football referees is scarce and almost non-existent. Therefore, and in order to establish the level of agreement between bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA) in elite football referees, the aim of this study was to compare fat mass (FM) and fat-free mass (FFM) values measured with these two different methods. Method: A total of 30 male referees belonging to 1st, 2nd and 2ndB categories, and 36 assistant referees from 1st and 2nd categories in the Spanish national league participated in this study. Total and regional FM and FFM were assessed using a portable BIA analyser TANITA BC 418-MA (Tanita Corp., Tokyo, Japan) and DXA (Hologic Corp. Software version 12.4, Bedford, MA 01730). Agreement between methods was assessed by plotting the results in Bland-Altman graphs and the presence of heteroscedasticity was also examined. Differences between methods were analysed by two-paired samples t-test. Results: For the whole group, BIA underestimated body fat percentage in 3.87 points (CI 95%=3.22-4.52; p=&lt;0.01) and overestimated kg of total FFM in 3.56 points (CI 95%=3.08-4.05; p=&lt;0.01), however, no heteroscedasticity was shown in any case (all p&gt;0.05). Conclusions: The present study suggests that according to DXA, BIA values calculated with a non-specific equation are underestimating total FM and, consequently, overestimating total FFM in male elite football referees. Objetivo: La literatura científica existente sobre la composición corporal en árbitros de fútbol es todavía escasa. Por lo tanto y para establecer el nivel de concordancia entre el análisis de impedancia bioeléctrica y la absorciometría de rayos X de doble energía en árbitros de fútbol de elite, el objetivo de este estudio fue comparar los valores de masa grasa (MG) y la masa libre de grasa (MLG) medidos con ambos métodos. Método: Un total de 30 árbitros pertenecientes a las categorías de 1ª, 2ª y 2ª división B, y 36 asistentes de 1ª y 2ª división de la liga española participaron en este estudio. La MG y la MLG tanto a nivel total como regional se evaluó utilizando la impedancia bioeléctrica TANITA BC 418-MA (Tanita Corp., Tokyo, Japan) y absorciometría de rayos X de doble energía (Hologic Corp. Software versión 12.4, Bedford, MA 01730). La concordancia entre métodos se evaluó con gráficos de Bland-Altman y también se examinó la presencia de heterocedasticidad. Las diferencias entre métodos se analizaron con la prueba T de Student para muestras relacionadas. Resultados: Para el total de la muestra, la impedancia bioeléctrica infraestimó el porcentaje de MG en 3.87 puntos (IC 95%=3.22-4.52; p=0.05). Conclusión: El presente estudio sugiere que, tomando como referencia la absorciometría de rayos X de doble energía, la impedancia bioeléctrica calculada a partir de una ecuación no especifica para árbitros, infraestima la MG y consecuentemente, sobreestima la MLG en árbitros de fútbol de elite

Toward a Neutral Single-Component Amidinate Iodide Aluminum Catalyst for the CO₂ Fixation into Cyclic Carbonates

A new iodide aluminum complex ({AlI(κ⁴-naphbam)}, 3) supported by a tetradentate amidinate ligand derived from a naphthalene-1,8-bisamidine precursor (naphbamH, 1) was obtained in quantitative yield via reaction of the corresponding methyl aluminum complex ({AlMe(κ⁴-naphbam)}, 2) with 1 equiv of I₂ in CH₂Cl₂ at room temperature. Complexes 2 and 3 were tested and found to be active as catalysts for the cyclic carbonate formation from epoxides at 80 °C and 1 bar of CO₂ pressure. A first series of experiments were carried out with 1.5 mol % of the alkyl complex 2 and 1.5 mol % of tetrabutylammonium iodide (TBAI) as a cocatalyst; subsequently, the reactions were carried out with 1.5 mol % of iodide complex 3 as a single-component catalyst. Compound 3 is one of the first examples of a nonzwitterionic halide single-component aluminum catalyst producing cyclic carbonates. The full catalytic cycle with characterization of all minima and transition states was characterized by quantum chemistry calculations (QCCs) using density functional theory. QCCs on the reaction mechanism support a reaction pathway based on the exchange of the iodine contained in the catalyst by 1 equiv of epoxide, with subsequent attack of I⁻ to the epoxide moiety producing the ring opening of the epoxide. QCCs triggered new insights for the design of more active halide catalysts in future explorations of the field