Discovery of CH and OH in the -513 km s-1 Ejecta of Eta Carinae

The very massive star, Eta Carinae, is enshrouded in an unusual complex of stellar ejecta, which is highly depleted in C and O, and enriched in He and N. This circumstellar gas gives rise to distinct absorption components corresponding to at least 20 different velocities along the line-of-sight. The velocity component at -513 kms-1 exhibits very low ionization with predominantly neutral species of iron-peak elements. Our statistical equilibrium/photoionization modeling indicates that the low temperature (T = 760 K) and high density (n_H=10^7 cm^-3) of the -513 kms-1 component is conducive to molecule formation including those with the elements C and O. Examination of echelle spectra obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the confirms the model's predictions. The molecules, H_2, CH, and most likely OH, have been identified in the -513 kms-1 absorption spectrum. This paper presents the analysis of the HST/STIS spectra with the deduced column densities for CH, OH and C I, and upper limit for CO. It is quite extraordinary to see molecular species in a cool environment at such a high velocity. The sharp molecular and ionic absorptions in this extensively CNO- processed material offers us a unique environment for studying the chemistry, dust formation processes, and nucleosynthesis in the ejected layers of a highly evolved massive star.Comment: tentatively scheduled for the ApJ 1 September 2005, v630, 1 issu

Bardeen-Petterson effect and the disk structure of the Seyfert galaxy NGC 1068

VLBA high spatial resolution observations of the disk structure of the active galactic nucleus NGC 1068 has recently revealed that the kinematics and geometry of this AGN is well characterized by an outer disk of H2O maser emission having a compact milliarcsecond (parsec) scale structure, which is encircling a thin rotating inner disk surrounding a ~10^7 M_\sun compact mass, likely a black hole. A curious feature in this source is the occurrence of a misalignment between the inner and outer parts of the disk, with the galaxy's radio jet being orthogonal to the inner disk. We interpret this peculiar configuration as due to the Bardeen-Petterson effect, a general relativistic effect that warps an initially inclined (to the black hole equator) viscous disk, and drives the angular momentum vector of its inner part into alignment with the rotating black hole spin. We estimate the time-scale for both angular momenta to get aligned as a function the spin parameter of the Kerr black hole. We also reproduce the shape of the parsec and kiloparsec scale jets, assuming a model in which the jet is precessing with a period and aperture angle that decrease exponentially with time, as expected from the Bardeen-Petterson effect.Comment: 12 pages, 3 figures, accepted for publication in The Astrophysical Journa

Newly described clinical and immunopathological feature of dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is an inflammatory cutaneous disease with typical histopathological and immunopathological findings clinically characterized by intensely pruritic polymorphic lesions with a chronic-relapsing course. In addition to classic clinical manifestations of DH, atypical variants are more and more frequently reported and histological and immunological are added to them, whereas the impact on quality of life of patients with DH is increasingly important to a certain diagnosis. The aim of this paper is to describe all the possible clinical, histological, and immunological variants of DH in order to facilitate the diagnosis of a rare disease and, therefore, little known

Self-gravitating warped discs around supermassive black holes

We consider warped equilibrium configurations for stellar and gaseous disks in the Keplerian force-field of a supermassive black hole, assuming that the self-gravity of the disk provides the only acting torques. Modeling the disk as a collection of concentric circular rings, and computing the torques in the non-linear regime, we show that stable, strongly warped precessing equilibria are possible. These solutions exist for a wide range of disk-to-black hole mass ratios $M_d/M_{bh}$, can span large warp angles of up to $\pm\sim 120\deg$, have inner and outer boundaries, and extend over a radial range of a factor of typically two to four. These equilibrium configurations obey a scaling relation such that in good approximation \phidot/\Omega\propto M_d/M_{bh} where \phidot is the (retrograde) precession frequency and $\Omega$ is a characteristic orbital frequency in the disk. Stability was determined using linear perturbation theory and, in a few cases, confirmed by numerical integration of the equations of motion. Most of the precessing equilibria are found to be stable, but some are unstable. The main result of this study is that highly warped disks near black holes can persist for long times without any persistent forcing other than by their self-gravity. The possible relevance of this to galactic nuclei is briefly discussed.Comment: 13 pages, 21 figures, published in MNRA

Quebra de dormência em diásporos de teca (Tectona grandis L.f.).

Tectona grandis L.f. é uma essência florestal exótica de importância econômica e social para o Brasil. As mudas dessa espécie são produzidas através de diásporos constituídos dos frutos com endocarpo e mesocarpo rígidos. O objetivo do presente trabalho foi avaliar o efeito de métodos de quebra de dormência na germinação das sementes desta espécie. Para superar a dormência do endocarpo e mesocarpo, os diásporos de teca foram submetidos à imersão em água quente, imersão em ácido sulfúrico (33,5%) e imersão em água corrente. Os diásporos foram distribuídos em substrato constituído de areia, e o teste de germinação foi realizado em câmara de germinação com temperatura de 30 ºC, sob luz branca durante oito horas por dia. As avaliações foram feitas diariamente, durante 60 dias. O método de imersão dos diásporos em ácido sulfúrico por três minutos, foi o tratamento mais eficiente, apresentando 73% das sementes germinadas

Comportamento da Macrofauna edáfica em diferentes modelos de arborização de cafeeiro Robusta (Coffea canephora) em Rondônia.

O levantamento da fauna edáfica do solo é uma forma indicada de avaliar a viabilidade em função do manejo deste tipo de sistema. O objetivo deste trabalho foi fazer um levantamento da ocorrência da macrofauna do solo em 05 (dez) propriedades cultivadas com o café Robusta (Coffea canephora) arborizado no município de Rolim de Moura, localizado na região da Zona da Mata/RO em duas épocas diferentes. Na época chuvosa e seca, as Ordens com maiores frequência de ocorrência foram Hymenoptera, Araneae, Coleoptera, Dermaptera, Orthoptera, Isoptera, Acari, Lithobiomorpha, Diptera, Hemiptera. Através do índice de diversidade de Shannon identificou-se propriedades com maior estabilidade, principalmente quando houve maior diversidade de espécies florestais nos SAFs. O manejo dos SAFs, o clima, a diversidade de espécies florestais e o tamanho das áreas amostradas possivelmente influenciam a diversidade de Ordens da macrofauna

Profile of a Cohort of 78 Italian Patients with Mucous Membrane Pemphigoid: Correlation Between Reactivity Profile and Clinical Involvement

Direct diagnosis of mucous membrane pemphigoid (MMP) is not easy. Circulating autoantibodies targeting bullous pemphigoid antigens of 180 kDa and 230 kDa (BP180 and BP230), \u3b16\u3b24 integrin, laminin 332 and type VII collagen (Col VII) are not always present. The aims of this study were to characterize the humoral immune response of a cohort of Italian patients with MMP, its association with clinical involvement and severity, and to design an algorithm for efficient serological diagnosis. Seventy-eight MMP sera were studied retrospectively by indirect immunofluorescence on salt-split skin, enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Indirect immunofluorescence on salt-split skin resulted in the most sensitive approach for diagnosis of MMP. BP180 was the major autoantigen in MMP patients with oral and cutaneous involvement. Significant associations were found between BP180 reactivity and oral and cutaneous localization of the lesions (p\u2009=\u20090.006), and between Col VII positivity and Setterfield severity score (p\u2009=\u20090.020)

Observational evidence of spin-induced precession in active galactic nuclei

We show that it is possible to explain the physical origin of jet precession in active galactic nuclei (AGNs) through the misalignment between the rotation axes of the accretion disk and of the Kerr black hole. We apply this scenario to quasars, Seyfert galaxies and also to the Galactic Center black hole Sgr A*, for which signatures of either jet or disk precession have been found. The formalism adopted is parameterized by the ratio of the precession period to the black hole mass and can be used to put constraints to the physical properties of the accretion disk as well as to the black hole spin in those systems.Comment: 10 pages, 1 figure, accepted for publication in ApJ Letter