How Do Nonlinear Voids Affect Light Propagation ?

Propagation of light in a clumpy universe is examined. As an inhomogeneous matter distribution, we take a spherical void surrounded by a dust shell where the ``lost mass'' in the void is compensated by the shell. We study how the angular-diameter distance behaves when such a structure exists. The angular-diameter distance is calculated by integrating the Raychaudhuri equation including the shear. An explicit expression for the junction condition for the massive thin shell is calculated. We apply these results to a dust shell embedded in a Friedmann universe and determine how the distance-redshift relation is modified compared with that in the purely Friedmann universe. We also study the distribution of distances in a universe filled with voids. We show that the void-filled universe gives a larger distance than the FRW universe by $\sim 5$ at $z \sim 1$ if the size of the void is $\sim 5$ of the Horizon radius.Comment: To appear in Prog. Theor. Phys. 10

Metal-nonmetal transition in LixCoO2 thin film and thermopower enhancement at high Li concentration

We investigate the transport properties of LixCoO2 thin films whose resistivities are nearly an order of magnitude lower than those of the bulk polycrystals. A metal-nonmetal transition occurs at ~0.8 in a biphasic domain, and the Seebeck coefficient (S) is drastically increased at ~140 K (= T*) with increasing the Li concentration to show a peak of magnitude ~120 \muV/K in the S-T curve of x = 0.87. We show that T* corresponds to a crossover temperature in the conduction, most likely reflecting the correlation-induced temperature dependence in the low-energy excitations

Effect of abscisic acid and defoliation on anthocyanin accumulation in Kyoho grapes (Vitis vinifera L. x V. labruscana BAILEY)

In Kyoho grapes, ABA treatment at 1000 ppm in the beginning of ripening enhanced anthocyanin accumulation in the skin without any effect on the contents of soluble solids and titratable acids in the juice.By defoliation at veraison, anthocyanin synthesis was completely inhibited, and the soluble solids content in the juice and sugar levels in the skin became much less than those of the control. Furthermore, endogenous ABA levels in the skin and flesh did not increase throughout ripening period.On such defoliated vines, the berries recovered anthocyanin accumulation by ABA application.From these results, it will be assumed that ABA which accumulates in the skin is one of the main factors involved in the anthocyanin synthesis.Der Einfluß von Abscisinsäure und Entblätterung auf die Anthocyanakkumulation in Trauben der Rebsorte Kyoho (Vitis vinifera L. x V. labruscana BAILEY)Wurden Kyoho-Trauben zu Beginn der Beerenreife mit 1 000 ppm ABS behandelt, so war in den Beerenhäuten verstärkt Anthocyan angereichert, ohne daß Mostgewicht und tritierbare Säure des Beerensaftes irgendwie beeinflußt waren. Durch Entblätterung der Reben zur Zeit des Weichwerdens der Beeren wurde die Anthocyansynthese vollkommen unterdrückt, und das Mostgewicht des Beerensaftes wie auch die Zuckerkonzentration der Beerenhaut waren gegenüber der Kontrolle bedeutend verringert. Ferner nahm die Konzentration der endogenen ABS in Beerenhaut und -fleisch während der ganzen Reifeperiode nicht zu.Bei den entblätterten Reben setzte nach der Applikation von ABS die Anthocyanakkumulation in den Beeren wieder ein.Aus den vorliegenden Ergebnissen wird gefolgert, daß die Anreicherung von ABS in der Beerenhaut einer der Hauptfaktoren ist, die an der Anthocyansynthese beteiligt sind

Regular projections of graphs with at most three double points

A generic immersion of a planar graph into the 2-space is said to be knotted if there does not exist a trivial embedding of the graph into the 3-space obtained by lifting the immersion with respect to the natural projection from the 3-space to the 2-space. In this paper we show that if a generic immersion of a planar graph is knotted then the number of double points of the immersion is more than or equal to three. To prove this, we also show that an embedding of a graph obtained from a generic immersion of the graph (does not need to be planar) with at most three double points is totally free if it contains neither a Hopf link nor a trefoil knot.Comment: 16 pages, 31 figure

Posterior interosseous nerve palsy secondary to pigmented villonodular synovitis of the elbow: Case report and review of literature

SummaryLocal tumor compression is the main mechanical cause of posterior interosseous nerve (PIN) palsy. The reported cases of these tumors do not include that of pigmented villonodular synovitis (PVNS). Here, we report a case of a 53-year-old male with a 9-year history of painless swelling in his left elbow and a few months of progressive weakness in his left hand. Imaging identified the mass, and histological examination of the biopsy specimens revealed PVNS. The mass was compressing the nerve at the arcade of Frohse, and we performed a complete resection of the mass. Following removal of the mass, the patient regained complete function in his left upper extremity, and no local recurrence has been detected after 2 postoperative years. The possibility of PVNS should be considered in the differential diagnosis of PIN palsy

Metastability in Interacting Nonlinear Stochastic Differential Equations II: Large-N Behaviour

We consider the dynamics of a periodic chain of N coupled overdamped particles under the influence of noise, in the limit of large N. Each particle is subjected to a bistable local potential, to a linear coupling with its nearest neighbours, and to an independent source of white noise. For strong coupling (of the order N^2), the system synchronises, in the sense that all oscillators assume almost the same position in their respective local potential most of the time. In a previous paper, we showed that the transition from strong to weak coupling involves a sequence of symmetry-breaking bifurcations of the system's stationary configurations, and analysed in particular the behaviour for coupling intensities slightly below the synchronisation threshold, for arbitrary N. Here we describe the behaviour for any positive coupling intensity \gamma of order N^2, provided the particle number N is sufficiently large (as a function of \gamma/N^2). In particular, we determine the transition time between synchronised states, as well as the shape of the "critical droplet", to leading order in 1/N. Our techniques involve the control of the exact number of periodic orbits of a near-integrable twist map, allowing us to give a detailed description of the system's potential landscape, in which the metastable behaviour is encoded

Fourier Duality as a Quantization Principle

The Weyl-Wigner prescription for quantization on Euclidean phase spaces makes essential use of Fourier duality. The extension of this property to more general phase spaces requires the use of Kac algebras, which provide the necessary background for the implementation of Fourier duality on general locally compact groups. Kac algebras -- and the duality they incorporate -- are consequently examined as candidates for a general quantization framework extending the usual formalism. Using as a test case the simplest non-trivial phase space, the half-plane, it is shown how the structures present in the complete-plane case must be modified. Traces, for example, must be replaced by their noncommutative generalizations - weights - and the correspondence embodied in the Weyl-Wigner formalism is no more complete. Provided the underlying algebraic structure is suitably adapted to each case, Fourier duality is shown to be indeed a very powerful guide to the quantization of general physical systems.Comment: LaTeX 2.09 with NFSS or AMSLaTeX 1.1. 97Kb, 43 pages, no figures. requires subeqnarray.sty, amssymb.sty, amsfonts.sty. Final version with (few) text and (crucial) typos correction