130 research outputs found
The Near-Horizon Limit of the Extreme Rotating d=5 Black Hole as a Homogenous Spacetime
We show that the spacetime of the near-horizon limit of the extreme rotating
d=5 black hole, which is maximally supersymmetric in N=2,d=5 supergravity for
any value of the rotation parameter j in [-1,1], is locally isomorphic to a
homogeneous non-symmetric spacetime corresponding to an element of the
1-parameter family of coset spaces SO(2,1)x SO(3)/SO(2)_j in which the subgroup
SO(2)_j is a combination of the two SO(2) subgroups of SO(2,1) and SO(3).Comment: Some points clarified and misprints corrected. Version to be
published in Classical and Quantum Gravit
Bowel-associated dermatosis-arthritis syndrome in an adolescent with short bowel syndrome
Bowel-associated dermatosis-arthritis syndrome (BADAS) is a neutrophilic dermatosis, characterized by the occurrence of arthritis and skin lesions related to bowel disease with or without bowel bypass. We report an unusual case of BADAS in a 15-year-old white male with congenital aganglionosis of the colon and hypoganglionosis of the small intestine and multiple bowel surgeries in childhood complicated by short bowel syndrome. He presented with recurrent peripheral polyarthritis, tenosynovitis, and painful erythematous subcutaneous nodules located on the dorsolateral regions of the legs and on the dorsa of the feet. Histological examination disclosed a neutrophilic dermatosis confirming the diagnosis of BADAS.Although an uncommon disease, especially at pediatric age, it is important to evoke the diagnosis of BADAS in children and adolescents with bowel disease, because treatment options and prognosis are distinct from other rheumatologic conditions
Einstein-Maxwell gravitational instantons and five dimensional solitonic strings
We study various aspects of four dimensional Einstein-Maxwell multicentred
gravitational instantons. These are half-BPS Riemannian backgrounds of minimal
N=2 supergravity, asymptotic to R^4, R^3 x S^1 or AdS_2 x S^2. Unlike for the
Gibbons-Hawking solutions, the topology is not restricted by boundary
conditions. We discuss the classical metric on the instanton moduli space. One
class of these solutions may be lifted to causal and regular multi `solitonic
strings', without horizons, of 4+1 dimensional N=2 supergravity, carrying null
momentum.Comment: 1+30 page
p-branes on the waves
We present a large family of simple, explicit ten-dimensional supergravity
solutions describing extended extremal supersymmetric Ramond-Ramond p-branes
embedded into time-dependent dilaton-gravity plane waves of an arbitrary
(isotropic) profile, with the brane world-volume aligned parallel to the
propagation direction of the wave. Generalizations to the non-extremal case are
not analyzed explicitly, but can be pursued as indicated.Comment: 11 pages; v.2 minor notation changes, minor typos corrected
(published version
Genetic and morphometric analyzes of Paralichthys species confirm the presence of P. brasiliensis in the Uruguayan waters
Paralichthys species have high commercial value and constitute a resource for demersal fisheries in the Southwestern Atlantic Ocean. Although six species have been described based on morphological characters for the Uruguayan and Argentinean waters, only the presence of three species is accepted, being their distribution still uncertain. Genetic tools are useful for species identification as a complement of morphological characters. This paper determines the genetic and morphometric variation between three species of Paralichthys that inhabiting Uruguayan waters. The interorbital width (IN) and the length from the mouth to the dorsal fin base (SD) of P. patagonicus differed significantly from the other two species (P. orbignyanus and P. brasiliensis). From a morphological perspective, individuals identified as P. orbignyanus formed two different groups. Clade Po_A included those belonging to oceanic coastal waters of Uruguay and deeper waters of the Rio de la Plata together with individuals of P. brasiliensis from ItajaĂ, Santa Catarina (Brazil). Individuals collected in the Rio de la Plata coastal and beach zone formed the clade Po_B group. Genetic analysis confirmed for the first time the presence of P. brasiliensis in Uruguayan and Rio de la Plata shelf waters and extends its known distribution area further south. Discriminant scores for P. orbygnianus separate individuals in two groups corresponding to the presence of two species. Molecular and morphological analysis showed individuals in the clade Po_A includes those collected in Uruguayan waters together with those collected in northern Brazilian waters belonging to the species P. brasiliensis
On d=4,5,6 Vacua with 8 Supercharges
We show how all known N=2, d=4,5,6 maximally supersymmetric vacua (Hpp-waves
and aDSxS solutions) are related through dimensional reduction/oxidation
preserving all the unbroken supersymmetries. In particular we show how the N=2,
d=5 family of vacua (which are the near-horizon geometry of supersymmetric
rotating black holes) interpolates between aDS_2xS^3 and aDS_3xS^2 in parameter
space and how it can be dimensionally reduced to an N=2, d=4 dyonic
Robinson-Bertotti solution with geometry aDS_2xS^2 and oxidized to an N=2, d=6
solution with aDS_3xS^3 geometry (which is the near-horizon of the self-dual
string).Comment: Latex2e, 19 pages, 1 figure. v2: typos corrected, refs. added. v3:
very minor corrections, more refs. added, version to be published in
Classical and Quantum Gravit
Gauge theories from wrapped and fractional branes
We compare two applications of the gauge/gravity correspondence to a non
conformal gauge theory, based respectively on the study of D-branes wrapped on
supersymmetric cycles and of fractional D-branes on orbifolds. We study two
brane systems whose geometry is dual to N=4, D=2+1 super Yang-Mills theory, the
first one describing D4-branes wrapped on a two-sphere inside a Calabi-Yau
two-fold and the second one corresponding to a system of fractional
D2/D6-branes on the orbifold R^4/Z_2. By probing both geometries we recover the
exact perturbative running coupling constant and metric on the moduli space of
the gauge theory. We also find a general expression for the running coupling
constant of the gauge theory in terms of the "stringy volume" of the two-cycle
which is involved in both types of brane systems.Comment: AMS-LaTeX, 35 pages, no figures. Minor typos corrected, version to
appear in NP
The Tensor Hierarchies of Pure N=2,d=4,5,6 Supergravities
We study the supersymmetric tensor hierarchy of pure (gauged) N=2,d=4,5,6
supergravity and compare them with those of the pure, ungauged, theories
(worked out by Gomis and Roest for d=5) and the predictions of the Kac-Moody
approach made by Kleinschmidt and Roest. We find complete agreement in the
ungauged case but we also find that, after gauging, new Stueckelberg symmetries
reduce the number of independent "physical" top-forms. The analysis has to be
performed to all orders in fermion fields.
We discuss the construction of the worldvolume effective actions for the
p-branes which are charged with respect to the (p+1)-form potentials and the
relations between the tensor hierarchies and p-branes upon dimensional
reduction.Comment: LaTeX2e file, 20 pages, 1 figure Results refined by extension of the
analysis to all orders in fermion
PAPULO-NODULES LOCATED TO BOTH LOWER EXTREMITIES
As doenças perfurantes caracterizam-se por eliminação transepidĂ©rmica de queratina ou de componentes do tecido conjuntivo dĂ©rmico. A dermatose perfurante adquirida atinge sobretudo doentes com diabetes mellitus (DM) e insuficiĂȘncia renal crĂłnica (IRC), especialmente sob diĂĄlise. Um doente do sexo masculino de 86 anos de idade, com antecedentes de DM2, Ă© observado com mĂșltiplas lesĂ”es pruriginosas, papulosas e papulo-nodulares, de coloração eritemato-violĂĄcea, com crosta central. As lesĂ”es localizavam-se a ambos os membros inferiores e tinham 2 meses de evolução. A biĂłpsia realizada mostrou solução de continuidade epidĂ©rmica preenchida por material fibroso e cĂ©lulas picnĂłticas, com eliminação de feixes de fibras de colagĂ©nio verticalizadas (coloração de Van-Gieson). O doente foi medicado com retinĂłide tĂłpico, com melhoria das lesĂ”es cutĂąneas.Perforating diseases are characterized by transepidermal elimination of degenerated material, including collagen or elastic fibers. Acquired perforating dermatosis affects patients with diabetes mellitus or renal disease, especially under dialysis. An 86-year-old diabetic patient presents with very pruritic erythematous-violaceus papules and papulo-nodules, with a central crust. Lesions were evoluting for 2 months and were located to both lower extremities. The biopsy revealed a depression with fibrinous material and picnotic cells. Van-Gieson coloration showed elimination of vertical collagen bundles. The patient was treated with topical retinoid, with complete resolution
All supersymmetric solutions of minimal supergravity in six dimensions
A general form for all supersymmetric solutions of minimal supergravity in
six dimensions is obtained. Examples of new supersymmetric solutions are
presented. It is proven that the only maximally supersymmetric solutions are
flat space, AdS_3 x S^3 and a plane wave. As an application of the general
solution, it is shown that any supersymmetric solution with a compact horizon
must have near-horizon geometry R^{1,1} x T^4, R^{1,1} x K3 or identified AdS_3
x S^3.Comment: 40 pages. v2: two references adde
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