Showing papers by "Federal Fluminense University published in 1983"
TL;DR: C Cyanogenesis of 800 plant specimens (108 species) growing on a sandy tract of land between the sea and an inner lagoon 400 m distant was found to increase with insect density and, hence, with distance from the seashore and seasonal variation towards summer.
30 citations
TL;DR: A method to bet on a football lottery with N games in such a way as to guarantee second prize, with the least number of forecasts (bets), is described.
12 citations
TL;DR: In this paper, the production de pions multiples a partir de l'observation de rayons gamma produits dans la chambre a emulsion exposee a Chacaltaya, Bolivie, a 5200 m au-dessus de mer.
Abstract: On etudie la production de pions multiples a partir de l'observation de rayons gamma produits dans la chambre a emulsion exposee a Chacaltaya, Bolivie, a 5200 m au-dessus de mer. On compile 80 evenements avec ∑Ej>20TeV. On discute des implications possibles sur les modeles de boule de feu
12 citations
TL;DR: In this article, it was shown that the Schrodinger equation with a logarithmic nonlinearity proposed originally by Birula and Mycielski can be derived within the context of stochastic mechanics.
11 citations
TL;DR: In this paper, general results for Green functions, mode frequencies and light scattering cross section for retarded modes in a ferromagnetic slab are given. And they hold for a more general geometry than the Voigt's one.
9 citations
TL;DR: In this article, the authors present a renormalization group calculation for the directed percolation problem in an anisotropic square lattice, in which the horizontal (vertical) bonds are present with a concentration x (concentration y).
Abstract: We present a renormalization group calculation for the directed percolation problem in an anisotropic square lattice, in which the horizontal (vertical) bonds are present with a concentration x (concentration y). The existence of an infinite path from the origin along a given direction θ is investigated in a xy phase diagram. Our method reproduces the exact known results for the x=1 (or y=1) limit for any θ. We also present an explicit calculation for the θ=45° case, and obtain the critical frontier and the expected cross-over of the correlation length exponent ν along this frontier On presente un calcul de groupe de renormalisation de la percolation dirigee sur un reseau carre anisotrope, sur lequel les liens horizontaux sont presents avec une concentration x. On etudie l'existence d'un chemin infini partant de l'origine et dirige dans une direction d'angle θ donne dans le diagramme de phase xy. La methode reproduit les resultats exacts pour x=1 ∀θ. On effectue aussi un calcul explicite pour θ=45° et on obtient la frontiere critique et le comportement de cross-over de l'exposant de la longueur de correlation ν le long de la frontiere
9 citations
TL;DR: Apres ablation des pedoncules oculaires, une bande blanche apparait dans la region mesogastrique du Crabe violoniste Uca uruguayensis determine les effets de plusieurs extraits qui exercent une action chromatique sur cette bande.
Abstract: [Apres ablation des pedoncules oculaires, une bande blanche apparait dans la region mesogastrique du Crabe violoniste Uca uruguayensis; nous avons determine les effets de plusieurs extraits qui exercent une action chromatique sur cette bande. Les extraits de ganglions cerebraux et d'hemolymphe provoquent a la fois une agregation du pigment des leucophores et une dispersion du pigment des melanophores dans les 15 minutes qui suivent l'injection, tandis que l'extrait des pedoncules oculaires affecte les erythrophores et les melanophores des seuls pereiopodes. Il est suggere que le controle du changement de couleur chez les crabes intacts depend du fonctionnement integre de deux centres neuroendocrines, l'un dans les pedoncules oculaires, l'autre dans les ganglions cerebraux., Apres ablation des pedoncules oculaires, une bande blanche apparait dans la region mesogastrique du Crabe violoniste Uca uruguayensis; nous avons determine les effets de plusieurs extraits qui exercent une action chromatique sur cette bande. Les extraits de ganglions cerebraux et d'hemolymphe provoquent a la fois une agregation du pigment des leucophores et une dispersion du pigment des melanophores dans les 15 minutes qui suivent l'injection, tandis que l'extrait des pedoncules oculaires affecte les erythrophores et les melanophores des seuls pereiopodes. Il est suggere que le controle du changement de couleur chez les crabes intacts depend du fonctionnement integre de deux centres neuroendocrines, l'un dans les pedoncules oculaires, l'autre dans les ganglions cerebraux.]
6 citations
TL;DR: In this article, a theory of the impurity band in doped semi-conductors was developed, using a tight-binding basis and a self-consistent treatment to handle the configurational averages.
4 citations
TL;DR: Diphosphoglycerate in μM concentrations stimulates feeding in Rhodnius prolixus, and it is suggested that it is a physiological phagostimulant for this blood-sucking insect.
Abstract: Diphosphoglycerate in μM concentrations stimulates feeding inRhodnius prolixus. Since diphosphoglycerate is present at a high concentration in red blood cells, and is resistant to apyrase hydrolysis, it is suggested that it is a physiological phagostimulant for this blood-sucking insect.
4 citations
1 Jan 1983
2 citations
1 Jan 1983
TL;DR: Observation chez un sujet presentant une ceto-acidose diabetique, echec du traitement qui contribue a la mort du sujet.
Abstract: Observation chez un sujet presentant une ceto-acidose diabetique. Echec du traitement qui contribue a la mort du sujet
TL;DR: In this article, the theory of Anderson, Halperin and Varma (AHV) for spin glasses was extended to ferromagnets with competing interactions, and the coupling between magnons and two level systems (TLS) leads to a ferromagnetic instability which is associated with the disappearance of long range magnetic order on cooling in reentrant ferromags.
TL;DR: The authors think that the presence of inflammatory reaction and the changes in the astrocytes in their first case are consistent with the effects of a virus.
Abstract: Two clinico-pathological cases of necrotic myelopathies with a distant malignancy are presented. The first patient had histiocytic medullary reticulosis and the second one had a renal cell carcinoma. The authors refered to other similar cases found in the literature. In both patients the pathological features in the spinal cord were similar to the other cases reported, but in their first case they found an intense inflammatory reaction and hyperplasia of astrocytes into bizarre giant forms. The cause of necrotizing myelopathy associated with neoplasms remain unknow. The authors think that the presence of inflammatory reaction and the changes in the astrocytes in their first case are consistent with the effects of a virus.
TL;DR: In this paper, the dispersion relation for the retarded surface modes in an antiferromagnet for a general propagation direction was obtained for general propagation directions in a general antifromagnetic network.
TL;DR: This is the first report of chromosomes of this type in the Osteichthyes (Pisces) studied, and the unstable behavior of these chromosomes during mitosis and meiosis as well as their heterochromatic nature, as detected by C-banding, are characteristics that emphasize their supernumerary nature.
Abstract: SUMMARYBoth males and females of the fish Prochilodus scrofa have a diploid number of 2n = 54. However, with the exception of a single female, all 59 specimens (25 ♀, 34 ♂) studied had 1–5 minutes accessory chromosomes. The unstable behavior of these chromosomes during mitosis and meiosis as well as their heterochromatic nature, as detected by C-banding, are characteristics that emphasize their supernumerary nature. This is the first report of chromosomes of this type in the Osteichthyes (Pisces).