The large-scale modulation of the density distribution in standard axionic CDM and its cosmological and physical impact

It is shown, that the energy density of coherent axion field oscillations in the cosmology of standard invisible axion should be distributed in the Universe in the form of archioles, being nonlinear inhomogeneous structure, reflecting the large scale distribution of Brownian structure of axion strings in the very early Universe. Spectrum of inhomogeneities, generated by archioles, is obtained and their effects in the spectrum and quadrupole anisotropy of relic radiation are considered. The axionic-string-decay-model-independent restriction on the scale of axion interaction is obtained.Comment: 8 pages, Talk presented at Workshop on Fundamental Physics at the Birth of the Universe II, Roma, May 19-24, 199

Gravitational hedgehog, stringy hedgehog and stringy sphere

We investigate the solutions of Einstein equations such that a hedgehog solution is matched to different exterior or interior solutions via a spherical shell. In the case where both the exterior and the interior regions are hedgehog solutions or one of them is flat, the resulting spherical shell becomes a stringy shell. We also consider more general matchings and see that in this case the shell deviates from its stringy character.Comment: 11 page

Magnetized cosmological perturbations

A large-scale cosmic magnetic field affects not only the growth of density perturbations, but also rotational instabilities and anisotropic deformation in the density distribution. We give a fully relativistic treatment of all these effects, incorporating the magneto-curvature coupling that arises in a relativistic approach. We show that this coupling produces a small enhancement of the growing mode on superhorizon scales. The magnetic field generates new nonadiabatic constant and decaying modes, as well as nonadiabatic corrections to the standard growing and decaying modes. Magnetized isocurvature perturbations are purely decaying on superhorizon scales. On subhorizon scales before recombination, magnetized density perturbations propagate as magneto-sonic waves, leading to a small decrease in the spacing of acoustic peaks. Fluctuations in the field direction induce scale-dependent vorticity, and generate precession in the rotational vector. On small scales, magnetized density vortices propagate as Alfv\'{e}n waves during the radiation era. After recombination, they decay slower than non-magnetized vortices. Magnetic fluctuations are also an active source of anisotropic distortion in the density distribution. We derive the evolution equations for this distortion, and find a particular growing solution.Comment: Revised version, typos corrected, to appear in Phys. Rev.

A cyclic universe with colour fields

The topology of the universe is discussed in relation to the singularity problem. We explore the possibility that the initial state of the universe might have had a structure with 3-Klein bottle topology, which would lead to a model of a nonsingular oscillating (cyclic) universe with a well-defined boundary condition. The same topology is assumed to be intrinsic to the nature of the hypothetical primitive constituents of matter (usually called preons) giving rise to the observed variety of elementary particles. Some phenomenological implications of this approach are also discussed.Comment: 21 pages, 9 figures; v.4: final versio

Redução fechada e fixação esquelética externa tipo I para tratamento de fraturas de tibiotarso em pombos domésticos (Columba livia) Closed reduction and type-I external skeletal fixation for treatment of tibiotarsus fractures in domestic pigeons (Columba livia)

Estudaram-se a redução fechada e a fixação esquelética externa tipo I para o tratamento de fraturas de tibiotarso em 10 pombos domésticos (Columba livia) adultos. As aves foram anestesiadas com a associação de xilazina e cetamina e em seguida foi realizada fratura do tibiotarso direito por pressão digital sobre a diáfise do membro. Quatro pinos de Kirschner, dois proximais e dois distais à linha da fratura, foram inseridos percutaneamente através de ambas as corticais ósseas e, após redução fechada da fratura, conectados externamente por uma barra de acrílico autopolimerizável na face lateral do membro. Em três aves foi observado radiograficamente desvio ósseo angular, porém, a função do membro não foi afetada. O tempo médio e o desvio-padrão para a cicatrização óssea foram 23,4± 3,0 dias. Os resultados demonstram que a redução fechada e a aplicação de fixador esquelético externo tipo I é um método efetivo para o tratamento de fraturas de tibiotarso em pombos domésticos (Columba livia).<br>Ten adult domestic pigeons (Columbalivia) were used in order to study closed reduction and type-I external skeletal fixation for tibiotarsus fractures. Anesthesia was induced with xylazine and ketamine hydrochloride and the right tibiotarsus was manually fractured by digital pressure applied at the mid-diaphysis. Kirschner wires were driven percutaneously through the bone, two proximal and two distal to the fracture site, and stabilized by an acrylic bar in the lateral surface of the tibiotarsus after closed reduction of the fracture. Abnormalities in bone angulation were observed radiographically in three birds, however, the function of the limb was not noticeably impaired. The mean &plusmn; standard deviation for fracture healing was 23.4± 3.0 days. The results showed that closed reduction and application of a type-I external skeletal fixation is an effective method of treating tibiotarsus fracture in domestic

Fixador esquelético pino-resina acrílica e enxerto ósseo esponjoso no tratamento de complicações secundárias à imobilização inadequada de fratura do rádio e ulna em cães Acrylic-pin external fixator and cancellous bone graft in the treatment of complications caused by inadequate immobilization of radius and ulna fracture in dogs

O objetivo do estudo foi avaliar a eficácia do fixador esquelético pino-resina, configuração tipo II, coadjuvado pelo enxerto ósseo esponjoso autólogo, no tratamento das complicações secundárias à imobilização inadequada de fraturas do rádio e ulna em 10 cães, com peso entre 1,8 e 33,6 kg. Detectou-se não-união (n=4), osteomielite (n=1), má-união (n=1), falência ou quebra de implante (n=4), sendo 60% das lesões referente ao uso prévio de pino intramedular no rádio. A montagem do fixador foi realizada com transfixação de pinos lisos em sua maioria angulados, cujas extremidades excedentes foram dobradas e estabilizadas com resina acrílica. Em todos os casos, utilizou-se enxerto esponjoso autólogo fresco, após debridamento do foco de fratura. O tempo de permanência do aparelho variou entre 45 dias e 5 meses e a maior complicação foi o afrouxamento dos pinos transfixantes. A consolidação das fraturas ocorreu por formação de calo periosteal de mínimo a moderado, indicando boa rigidez da montagem.<br>The aim of this study was to evaluate the acrylic-pin external fixator, type II-configuration, and cancellous bone autograft for treating complications of radius and ulna fractures in 10 dogs weighing between 1.8 and 33.6 kg. Nonunion (n=4), osteomyelitis (n=1), malunion (n=1), failure or breakage of implant (n=4) were detected, and 60 % of them were associated with previous intramedullary pin placement in the radius. The fixator frame was constructed using most of the smooth transfixation pins angled. The fixation rods were constructed by placing acrylic resin over the ends of the transfixation pins that were previously bent. In all cases fresh cancellous bone autograft was used after cleaning of the fracture site. The permanence time of the external fixator ranged from 45 days to 5 months, and the most important complication was pin loosening. Fracture healing was by minimal to moderate periosteal callus, suggesting good rigidity of the frame configuration