Infinite index extensions of local nets and defects

Subfactor theory provides a tool to analyze and construct extensions of Quantum Field Theories, once the latter are formulated as local nets of von Neumann algebras. We generalize some of the results of [LR95] to the case of extensions with infinite Jones index. This case naturally arises in physics, the canonical examples are given by global gauge theories with respect to a compact (non-finite) group of internal symmetries. Building on the works of Izumi, Longo, Popa [ILP98] and Fidaleo, Isola [FI99], we consider generalized Q-systems (of intertwiners) for a semidiscrete inclusion of properly infinite von Neumann algebras, which generalize ordinary Q-systems introduced by Longo [Lon94] to the infinite index case. We characterize inclusions which admit generalized Q-systems of intertwiners and define a braided product among the latter, hence we construct examples of QFTs with defects (phase boundaries) of infinite index, extending the family of boundaries in the grasp of [BKLR16].Comment: 50 page

Lazy AC-Pattern Matching for Rewriting

We define a lazy pattern-matching mechanism modulo associativity and commutativity. The solutions of a pattern-matching problem are stored in a lazy list composed of a first substitution at the head and a non-evaluated object that encodes the remaining computations. We integrate the lazy AC-matching in a strategy language: rewriting rule and strategy application produce a lazy list of terms.Comment: In Proceedings WRS 2011, arXiv:1204.531

Linear plasmon dispersion in single-wall carbon nanotubes and the collective excitation spectrum of graphene

We have measured a strictly linear pi-plasmon dispersion along the axis of individualized single wall carbon nanotubes, which is completely different from plasmon dispersions of graphite or bundled single wall carbon nanotubes. Comparative ab initio studies on graphene based systems allow us to reproduce the different dispersions. This suggests that individualized nanotubes provide viable experimental access to collective electronic excitations of graphene, and it validates the use of graphene to understand electronic excitations of carbon nanotubes. In particular, the calculations reveal that local field effects (LFE) cause a mixing of electronic transitions, including the 'Dirac cone', resulting in the observed linear dispersion

Semiarid Grassland and Winter Cereals for Lamb Production in Northeast Patagonia, Argentina

In northeastern Patagonia where grain crops often led to harvest failure, low yields and a high drought risk, a lamb production system was established. On a 10 years old agriculture wheat cropping was interrupted in 1996, allowing re-vegetation through exclusion of grazing. Natural grassland recovered, prevailing the species Stipa tenuis, Piptochaetium napostaense, Stipa ambigua. Part of the plot was sown to wheat grass (Thinopyrum ponticum). In 1999, to improve sheep feeding, oat (Avena sativa) and barley (Hordeum vulgare) were sown for grazing during winter-spring season. In this system Corriedale sheep, Texel x australian Merino (TEMA) and Ile de France x Australian Merino (ILMA) crosses were tested. Fertility, prolificacy, lamb mortality and weaning were evaluated. No differences among genotypes (α= 0.05) were found. Weaned lamb weight per ewe was significantly higher in cross ewes (p\u3c 0.0035), while production efficiency showed no significant differences among genotypes (α= 0.05), because of the higher body live weight of the crosses (p\u3c 0.0001). Yields of 16.4; 19.4 and 20.2kg lamb hectare–1 for Corriedale, TEMA and ILMA respectively were calculated, which represent an increase of 18 and 23 %. These differences could become economically significant in the production system under study

Ajuste osmótico en Leymus cinereus cv. “Trailhead” bajo condiciones de campo

El ajuste osmótico se ha reconocido como una respuesta importante de adaptación a condiciones de estrés hídrico en las plantas superiores. Aunque Leymus cinereus cv. “Trailhead” tiene la reputación de ser una especie componente de los pastizales naturales con una alta tolerancia a la sequía, su capacidad para ajustarse osmóticamente no se ha demostrado bajo condiciones de campo. Este estudio examinó la ocurrencia o no de ajuste osmótico durante la primavera en plantas de Leymus cinereus cv. “Trailhead” que crecieron bajo condiciones de campo en una zona árida de Patagonia. Las plantas fueron examinadas por esta característica adaptativa luego de su implantación en el campo tres años antes. Se recolectaron láminas foliares de esta especie y se construyeron curvas presión-volumen. Los resultados mostraron que Leymus cinereus cv. “Trailhead” mantuvo la presión de turgencia aún cuando declinó el potencial hídrico, indicando la existencia de ajuste osmótico. Más aún, la presión de turgencia máxima se incrementó cuando el potencial hídrico fue máximo luego de un período de tres semanas. Esta respuesta es típica en plantas con una historia previa de ajuste osmótico como resultado de condiciones de estrés hídrico.Osmotic adjustment has been recognized to be an important adaptive response to water stress in higher plants. Although Leymus cinereus cv. ‘’Trailhead’’ is reputedly a very drought-tolerant rangeland plant, its ability to adjust osmotically in the field has not previously been reported. This study examined the either occurrence or not of osmotic adjustment in field-grown plants of Leymus cinereus cv. ‘’Trailhead’’ during late spring in an arid zone of Patagonia. Plants of this species had been established in the field three years before. With this purpose, leaf lamina of this species were collected and pressure-volume curves made. Results showed turgor maintenance in the face of declining leaf water potentials (i.e., osmotic adjustment) in the study species. Even more, maximum pressure at maximum leaf water potential was increased during a 3-week-period. This response is typical of plants with a previous history of osmotic adjustment as a result of water stress.Fil: Torres, Yanina Alejandra. Universidad Nacional del Sur. Departamento de Agronomia. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Busso, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Montenegro, Oscar Alberto. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental de Patagones; ArgentinaFil: Giorgetti, Hugo Dosindo. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental de Patagones; ArgentinaFil: Rodríguez, H. D.. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental de Patagones; ArgentinaFil: Bentivegna, Diego Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentin

Magnetic circular dichroism of x-ray absorption spectroscopy at rare-earth L2,3 edges in RE2Fe14B compounds (RE = La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu)

Magnetic circular dichroism (MCD) in the x-ray absorption spectroscopy (XAS) at the L2,3 edges for almost entire series of rare-earth (RE) elements in RE2Fe14B, is studied experimentally and theoretically. By a quantitative comparison of the complicated MCD spectral shapes, we find that (i) the 4f-5d intra-atomic exchange interaction not only induces the spin and orbital polarization of the 5d states, which is vital for the MCD spectra of the electric dipole transition from the 2p core states to the empty 5d conduction band, but also it accompanies a contraction of the radial part of the 5d wave function depending on its spin and orbital state, which results in the enhancement of the 2p-5d dipole matrix element, (ii) there are cases where the spin polarization of the 5d states due to the hybridization with the spin polarized 3d states of surrounding irons plays important roles, and (iii) the electric quadrupole transition from the 2p core states to the magnetic vale! nce 4f states is appreciable at the pre-edge region of the dipole spectrum. Especially, our results evidence that it is important to include the enhancement effect of the dipole matrix element in the correct interpretation of the MCD spectra at the RE L2,3 edges.Comment: 9 pages, 5 figures, 1 table, REVTe

A semi-classical field method for the equilibrium Bose gas and application to thermal vortices in two dimensions

We develop a semi-classical field method for the study of the weakly interacting Bose gas at finite temperature, which, contrarily to the usual classical field model, does not suffer from an ultraviolet cut-off dependence. We apply the method to the study of thermal vortices in spatially homogeneous, two-dimensional systems. We present numerical results for the vortex density and the vortex pair distribution function. Insight in the physics of the system is obtained by comparing the numerical results with the predictions of simple analytical models. In particular, we calculate the activation energy required to form a vortex pair at low temperature.Comment: 19 page

XAS investigation on polyvalent cation intercalation in V2O5 aerogels.

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Antigen receptor repertoires of one of the smallest known vertebrates

The rules underlying the structure of antigen receptor repertoires are not yet fully defined, despite their enormous importance for the understanding of adaptive immunity. With current technology, the large antigen receptor repertoires of mice and humans cannot be comprehensively studied. To circumvent the problems associated with incomplete sampling, we have studied the immunogenetic features of one of the smallest known vertebrates, the cyprinid fish Paedocypris sp. “Singkep” (“minifish”). Despite its small size, minifish has the key genetic facilities characterizing the principal vertebrate lymphocyte lineages. As described for mammals, the frequency distributions of immunoglobulin and T cell receptor clonotypes exhibit the features of fractal systems, demonstrating that self-similarity is a fundamental property of antigen receptor repertoires of vertebrates, irrespective of body size. Hence, minifish achieve immunocompetence via a few thousand lymphocytes organized in robust scale-free networks, thereby ensuring immune reactivity even when cells are lost or clone sizes fluctuate during immune responses

Impact of serotonin 2C receptor null mutation on physiology and behavior associated with nigrostriatal dopamine pathway function

The impact of serotonergic neurotransmission on brain dopaminergic pathways has substantial relevance to many neuropsychiatric disorders. A particularly prominent role has been ascribed to the inhibitory effects of serotonin 2C receptor (5-HT2CR) activation on physiology and behavior mediated by the mesolimbic dopaminergic pathway, particularly in the terminal region of the nucleus accumbens. The influence of this receptor subtype on functions mediated by the nigrostriatal dopaminergic pathway is less clear. Here we report that a null mutation eliminating expression of 5-HT2CRs produces marked alterations in the activity and functional output of this pathway. 5-HT2CR mutant mice displayed increased activity of substantia nigra pars compacta (SNc) dopaminergic neurons, elevated baseline extracellular dopamine concentrations in the dorsal striatum (DSt), alterations in grooming behavior, and enhanced sensitivity to the stereotypic behavioral effects of D-amphetamine and GBR 12909. These psychostimulant responses occurred in the absence of phenotypic differences in drug-induced extracellular dopamine concentration, suggesting a phenotypic alteration in behavioral responses to released dopamine. This was further suggested by enhanced behavioral responses of mutant mice to the D1 receptor agonist SKF 81297. Differences in DSt D1 or D2 receptor expression were not found, nor were differences in medium spiny neuron firing patterns or intrinsic membrane properties following dopamine stimulation. We conclude that 5-HT2CRs regulate nigrostriatal dopaminergic activity and function both at SNc dopaminergic neurons and at a locus downstream of the DSt.peer-reviewe