Dual symmetry and the vacuum energy

In this work we present a new hidden symmetry in gravity for the scale factor in the FRW model, for $k=0$. This exact symmetry vanishes the cosmological constant. We interpret this hidden symmetry as a dual symmetry in the sense that appears in the string theory.Comment: 7 pages, no figures, work sent to Class. Quantum Gra

Supersymmetric Barotropic FRW Model and Dark Energy

Using the superfield approach we construct the $n=2$ supersymmetric lagrangian for the FRW Universe with barotropic perfect fluid as matter field. The obtained supersymmetric algebra allowed us to take the square root of the Wheeler-DeWitt equation and solve the corresponding quantum constraint. This model leads to the relation between the vacuum energy density and the energy density of the dust matter.Comment: 11 pages, minor corrections, published versio

The mathematical description of the electrosynthesis of composites of oxy-hydroxycompounds cobalt with polypyrrole overooxidazed

The electrosynthesis of the composite with of the overoxidized polypyrrole with cobalt oxy-hydroxide in strongly acidic media has been described mathematically, using linear stability theory and bifurcation analysis. The steadystates stability conditions and oscillatory and monotonic instability requirements have been described too. The system´s behavior was compared with behavior of other systems with overoxidation, electropolymerization of heterocyclic compounds and electrosynthesis of the cobalt oxy-hydroxides

\u3ci\u3eUrotrema shirleyae\u3c/i\u3e n. sp. (Trematoda: Digenea: Urotrematidae) in \u3ci\u3eNorops oxylophus\u3c/i\u3e and \u3ci\u3eN. cupreus\u3c/i\u3e (Squamata: Iguania: Polychrotidae) from the Área de Conservación Guanacaste, Costa Rica

A new species of Urotrema inhabits Norops oxylophus and Norops cupreus from the Área de Conservación Guanacaste, Costa Rica. The new species is most similar to Urotrema scabridum but differs by having a relatively longer esophagus, at least 10% of the total body length versus 4-8% in U. scabridum; an oral sucker width:ventral sucker width ratio less than 1:1 (averaging 1:0.76) versus 1:1 or greater; an oral sucker width:pharyngeal width ratio less than 1:0.5 (averaging 1:0.42) versus greater than 1:0.5; and by having many transversely oriented posttesticular uterine loops versus a few vertically oriented posttesticular uterine loops

Layered switch architectures for high-capacity optical transport networks

Cataloged from PDF version of article.We propose and analyze layered switch architectures that possess high design flexibility, greatly reduced switch size, and high expandability. The improvement in loss and crosstalk due to the reduced switch size is also discussed. Theoretical models have been developed to compute the network blocking probability using these architectures. Low blocking probability and high network utilization are achieved because of the capability of communication between layers in adjacent switches. The results show that the proposed layered switch architectures are very attractive for high-capacity optical transport networks

Two New Species of \u3ci\u3eRhabdias\u3c/i\u3e (Nematoda: Rhabdiasidae) from the Marine Toad, \u3ci\u3eBufo marinus\u3c/i\u3e (L.) (Lissamphibia: Anura: Bufonidae), in Central America

Two new Rhabdias species are described from the lungs of the cane toad Bufo marinus (L.) from Costa Rica and Nicaragua. Rhabdias alabialis n. sp. differs from other known species of the genus by the remarkable morphology of its head end, i.e., the absence of lips or pseudolabia, the slitlike oral opening, and the triangular shape of the buccal capsule in apical view. Rhabdias pseudosphaerocephala n. sp. is identified as a form previously known in Central and South America as Rhabdias sphaerocephala Goodey, 1924, a species initially described from toads in Europe. The new species is differentiated from R. sphaerocephala based on head-end morphology and sequences of nuclear rDNA

Two New Species of \u3ci\u3eRhabdias\u3c/i\u3e (Nematoda: Rhabdiasidae) from the Marine Toad, \u3ci\u3eBufo marinus\u3c/i\u3e (L.) (Lissamphibia: Anura: Bufonidae), in Central America

Two new Rhabdias species are described from the lungs of the cane toad Bufo marinus (L.) from Costa Rica and Nicaragua. Rhabdias alabialis n. sp. differs from other known species of the genus by the remarkable morphology of its head end, i.e., the absence of lips or pseudolabia, the slitlike oral opening, and the triangular shape of the buccal capsule in apical view. Rhabdias pseudosphaerocephala n. sp. is identified as a form previously known in Central and South America as Rhabdias sphaerocephala Goodey, 1924, a species initially described from toads in Europe. The new species is differentiated from R. sphaerocephala based on head-end morphology and sequences of nuclear rDNA

The mechanism for the electrooxidation of procarbazine pharmaceutical preparation in alkaline media and its mathematical description

The mechanism for the electrooxidation of procarbazine in alkaline media has been proposed. The process is realized completely on the electrode surface and is adsorption-controlled. The oscillatory behavior in this case is more probable, than for neutral media and may be caused by influences of electrochemical oxidation and salt dissolution from the electrode surface

\u3ci\u3eParallopharynx\u3c/i\u3e spp. (Trematoda: Digenea: Plagiorchioidea) in Iguanian Lizards from the Área de Conservación Guanacaste, Guanacaste, Costa Rica, including \u3ci\u3eParallopharynx matternae\u3c/i\u3e n. sp. in \u3ci\u3eBasiliscus basiliscus\u3c/i\u3e (Squamata: Iguania: Corytophanidae)

We report three species of the digenean genus Parallopharynx, one previously undescribed, from the Área de Conservación Guanacaste (ACG) in northwestern Costa Rica. Parallopharynx gonzalezi, which was originally described in Basiliscus sp. and Ctenosaura similis from central Costa Rica, inhabits C. quinquecarinata; P. jonesi, originally described in Anolis lionotus (syn. Norops oxylophus) from Nicaragua, inhabits N. oxylophus, N. biporcatus, and Basiliscus basiliscus; and the new species, which inhabits B. basiliscus. Parallopharynx matternae n. sp. differs from all other members of the genus by having a metraterm extending posteriad from the genital pore to the posterior margin of the ventral sucker, whereas in P. arctus and P. gonzalezi, the metraterm never surpasses the midlevel of the ventral sucker and in P. jonesi it never passes the anterior margin of the ventral sucker, and by having an oral sucker that does not exceed 150 μm in diameter with a subsequent greater oral-ventral sucker width ratio ranging from 1:0.88-1.12 (averaging 1:1), whereas values range from 1:0.71-0.83 for P. gonzalezi and P. arctus, and from 1:0.59-0.68 for P. jonesi. Parallopharynx spp. possesses Y-shaped excretory vesicles with a long central stem and short arms bifurcating immediately posterior to the ovary; similar to those found in members of the Telorchiidae. Additional similarities in the relative positions of the gonads and the structure of the cirrus sac and metraterm indicate a close relationship between Parallopharynx and members of the Telorchiidae