LIBERTAÇÃO NAS TRILHAS DA JUSTIÇA: Estudo histórico e hermenêutico de Isaías 42,1-4

O presente trabalho tem como objetivo propor um estudo do cântico do escravo de Javé em Isaías 42,1- 4. Javé apresenta uma nova liderança, com um novo jeito de pensar e de agir para reconstruir um mundo novo baseado no direito e na solidariedade. É uma tarefa desafiadora para mim e ao mesmo tempo uma alegria em poder compartilhar com os meus amigos o conteúdo de um texto do Antigo Testamento. Afinal, o cântico do escravo de Javé é uma fonte inesgotável de sabedoria. Saciou o povo judaíta exilado a de dois mil e quinhentos anos atrás e continua jorrando água viva até em nossos dias matando a sede de todos aqueles e aquelas que lutam pela justiça. Os versos escolhidos são frutos de uma experiência de vida concreta dos exilados desacreditados por todos no cativeiro da Babilônia. No fundo é uma crítica aos falsos deuses criados pelos poderosos para justificar um sistema de opressão. A criatividade do profeta está em retomar os eventos históricos que marcaram a vida do povo exilado e atualizá-los dentro de um novo contexto histórico. Isto demonstra sua agilidade no conhecimento. Cada palavra é pensada dentro de um contexto maior envolvendo a vida e a história. O profeta é um sábio poeta, que fala de Deus como ninguém falou antes. Utiliza símbolos, imagens e metáforas que apontam para um mundo novo que ainda não existe, onde reinará o direito, a justiça e a paz. Essa mudança acontecerá a partir da missão que a liderança eleita desempenhará junto do povo oprimido e injustiçado. O líder será como o fermento na massa para a nova sociedade, baseada na igualdade e na partilha. O espírito de Javé estará agindo sobre ele para que ele não desanime da missão e que ela possa alcançar o seu objetivo. Essa nova liderança eleita por Javé agirá discretamente em silêncio entre os pobres e enfraquecidos. A missão beneficiará primeiramente às nações. Aqueles e aquelas que vivem em terras estrangeiras como migrantes. Depois contemplará de modo especial os pobres que estão correndo risco de vida, cana rachada e pavio vacilante e por fim a missão atingirá todos os povos da terra. Essa perspectiva traduz a vontade de Deus que é a salvação de toda a humanidade.(AU)

Inactivation of ethanol-inducible cytochrome P450 and other microsomal P450 isozymes by trans-4-hydroxy-2-nonenal, a major product of membrane lipid peroxidation.

Of the microsomal P450 cytochromes, the ethanol-inducible isoform, P450 2E1, is believed to be predominant in leading to oxidative damage, including the generation of radical species that contribute to lipid peroxidation, and in the reductive beta-scission of lipid hydroperoxides to give hydrocarbons and aldehydes. In the present study, the sensitivity of a series of P450s to trans-4-hydroxy-2-nonenal (HNE), a known toxic product of membrane lipid peroxidation, was determined. After incubation of a purified cytochrome with HNE, the other components of the reconstituted system (NADPH-cytochrome P450 reductase, phosphatidylcholine, and NADPH) were added, and the rate of oxygenation of 1-phenylethanol to yield acetophenone was assayed. Inactivation occurs in a time-dependent and HNE concentration-dependent manner, with P450s 2E1 and 1A1 being the most sensitive, followed by isoforms 1A2, 3A6, and 2B4. At an HNE concentration of 0.24 microM, which was close to the micromolar concentration of the enzyme, four of the isoforms were significantly inhibited, but not P450 2B4. In other experiments, the reductase was shown to be only relatively weakly inactivated by HNE. P450s 2E1 and 2B4 in microsomal membranes from animals induced with acetone or phenobarbital, respectively, are as readily inhibited as the purified forms. Evidence was obtained that the P450 heme is apparently not altered and the sulfur ligand is not displaced, that substrate protects against HNE, and that the inactivation is reversed upon dialysis. Higher levels of reductase or substrate do not restore the activity of inhibited P450 in the catalytic assay. Our results suggest that the observed inhibition of the various P450s is of sufficient magnitude to cause significant changes in the metabolism of foreign compounds such as drugs and chemical carcinogens by the P450 oxygenase system at HNE concentrations that occur in biological membranes. In view of the known activities of P450 2E1 in generating lipid hydroperoxides and in their beta-scission, its inhibition by this product of membrane peroxidation may provide a negative regulatory function.

MEGARA: the future IFU and MOS of the 10.4 M GTC

In these proceedings we summarize the characteristics and current status of MEGARA, the future optical IFU and MOS for the 10.4 m GTC. MEGARA is being built by a Consortium led by the UCM (Spain) that also includes the INAOE (Mexico), the IAA-CSIC (Spain) and the UPM (Spain). The MEGARA IFU offers two different bundles, one called LCB with a field-of-view of 14 x 12 arcsec^2 and a spaxel size of 0.685 arcsec yielding spectral resolutions between R=6000-19000 and another one called SCB covering 10 x 8 arcsec^2 with 0.48 arcsec spaxels and resolutions R=8000-25000. The MOS component allows observing up to 100 targets in 3.5x3.5 arcmin^2. In September 2010 MEGARA was selected as the next optical spectrograph for GTC. Its PDR is scheduled for March 2012 with First Light on 2015.

An XMM-Newton view of FeKα in high-mass X-ray binaries

We present a comprehensive analysis of the whole sample of available XMM-Newton observations of high-mass X-ray binaries (HMXBs) until August 2013, focusing on the FeKα emission line. This line is key to better understanding the physical properties of the material surrounding the X-ray source within a few stellar radii (the circumstellar medium). We collected observations from 46 HMXBs and detected FeKα in 21 of them. We used the standard classification of HMXBs to divide the sample into different groups. We find that (1) different classes of HMXBs display different qualitative behaviours in the FeKα spectral region. This is visible especially in SGXBs (showing ubiquitous Fe fluorescence but not recombination Fe lines) and in γ Cass analogues (showing both fluorescent and recombination Fe lines). (2) FeKα is centred at a mean value of 6.42 keV. Considering the instrumental and fits uncertainties, this value is compatible with ionization states that are lower than Fe xviii. (3) The flux of the continuum is well correlated with the flux of the line, as expected. Eclipse observations show that the Fe fluorescence emission comes from an extended region surrounding the X-ray source. (4) We observe an inverse correlation between the X-ray luminosity and the equivalent width of FeKα (EW). This phenomenon is known as the X-ray Baldwin effect. (5) FeKα is narrow (σline< 0.15 keV), reflecting that the reprocessing material does not move at high speeds. We attempt to explain the broadness of the line in terms of three possible broadening phenomena: line blending, Compton scattering, and Doppler shifts (with velocities of the reprocessing material V ~ 1000 km s-1). (6) The equivalent hydrogen column (NH) directly correlates to the EW of FeKα, displaying clear similarities to numerical simulations. It highlights the strong link between the absorbing and the fluorescent matter. (7) The observed NH in supergiant X-ray binaries (SGXBs) is in general higher than in supergiant fast X-ray transients (SFXTs). We suggest two possible explanations: different orbital configurations or a different interaction compact object – wind. (8) Finally, we analysed the sources IGR J16320-4751 and 4U 1700-37 in more detail, covering several orbital phases. The observed variation in NH between phases is compatible with the absorption produced by the wind of their optical companions. The results clearly point to a very important contribution of the donor’s wind in the FeKα emission and the absorption when the donor is a supergiant massive star.

Letter from William Croswell to James Maury, 1808 June 4

Draft of a letter to James Maury, the American consul in Liverpool, with information about Croswell's failed plans to publish a map.

Letter from William Croswell to Daniel P. Colesworthy, 1817 October 4

Copy of a one-page letter concerning the payment of a bill.

Letter from William Croswell to Benjamin Webb, 1822 September 4

Draft of a one-page letter primarily concerning Croswell's Mercator maps.

Letter from William Croswell to Harrison G. Otis, 1833 November 4

Two drafts of a letter requesting financial assistance.