742 research outputs found

    Investigating evidence for different black hole accretion modes since redshift z~1

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    Chandra data in the COSMOS, AEGIS-XD and 4Ms CDFS are combined with optical/near-IR photometry to determine the rest-frame U-V vs V-J colours of X-ray AGN hosts at mean redshifts 0.40 and 0.85. This combination of colours (UVJ) provides an efficient means of separating quiescent from star-forming, including dust reddened, galaxies. Morphological information emphasises differences between AGN split by their UVJ colours. AGN in quiescent galaxies are dominated by spheroids, while star-forming hosts are split between bulges and disks. The UVJ diagram of AGN hosts is then used to set limits on the accretion density associated with evolved and star-forming systems. Most of the black hole growth since z~1 is associated with star-forming hosts. Nevertheless, ~15-20% of the X-ray luminosity density since z~1, is taking place in the quiescent region of the UVJ diagram. For the z~0.40 subsample, there is tentative evidence (2sigma significance), that AGN split by their UVJ colours differ in Eddington ratio. AGN in star-forming hosts dominate at high Eddington ratios, while AGN in quiescent hosts become increasingly important as a fraction of the total population toward low Eddington ratios. At higher redshift, z~0.8, such differences are significant at the 2sigma level only at Eddington ratios >1e-3. These findings are consistent with scenarios in which diverse accretion modes are responsible for the build-up of SMBHs at the centres of galaxies. We compare our results with the GALFORM semi-analytic model, which postulates two black hole fuelling modes, the first linked to star-formation and the second occuring in passive galaxies. GALFORM predicts a larger fraction of black hole growth in quiescent galaxies at z<1, compared to the data. Relaxing the strong assumption of the model that passive AGN hosts have zero star-formation rate could reconcile this disagreement.Comment: MNRAS accepte

    Proposed Steps to Projects Development in the Public Sector

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    Public Policy and projects have been the subject of discussion in public organizations, with the argument that it organizations has resources, but there are no projects to invest. This research aims to suggest a step-by-step proposal to elaborate a project, based on a public policy, in a way that will improve public management, with specific results and contribute to the quality of life of citizens and society. In this research was analyzed the concepts of public management, public policy, programs and projects, which resulted in a logical, interrelated proposal, consisting of steps that comprise a step by step to elaborate project to a public policy. He sought the qualitative aspect and used the bibliographical research as methodology. Structuring the work in chapters organizing in introduction, theoretical survey and its analysis, proposed a step by step to elaborate project and concluded with the final considerations

    MPO-ANCA-Associated Necrotizing Glomerulonephritis in Rheumatoid Arthritis; a Case Report and Review of Literature

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    BACKGROUND: Renal involvement in rheumatoid arthritis (RA) is common and has a negative impact on patient survival. Only few cases have been reported of necrotizing glomerulonephritis (GN) associated with myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) in patients with RA. CASE PRESENTATION: We report a patient with RA who developed a necrotizing GN associated with ANCA-MPO, treated with rituximab (RTX). A 55-year-old man with a 27-year history of RA under secukinumab was referred to our nephrology clinic with worsening renal function associated with microhematuria and proteinuria. Our laboratory evaluation showed hypocomplementemia and positive titers for MPO-ANCA (615 U/mL). A renal biopsy demonstrated pauci-immune necrotizing GN. The patient was treated with 3 consecutive pulses of methylprednisolone followed by oral prednisolone (1 mg/Kg) and rituximab (1000 mg, repeated 14 days later). After a 10-month follow-up, the arthritis remains well-controlled, renal function stabilized, proteinuria improved and MPO-ANCA titer normalized (6.3 U/mL). CONCLUSIONS: Necrotizing GN is a rare but a serious condition and an early diagnosis is essential to treatment. This is the first case of necrotizing GN (without extra-renal manifestations of vasculitis) in a patient with active RA, successfully treated with RTX.info:eu-repo/semantics/publishedVersio

    Micronutrient and functional compounds biofortification of maize grains.

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    Made available in DSpace on 2014-02-26T23:26:28Z (GMT). No. of bitstreams: 1 Sergioartigoaceito.pdf: 5378350 bytes, checksum: 59fbcfa3d675e5c3bda13c31a8eb4bef (MD5) Previous issue date: 2014-02-26201

    Electrochemical CO2 reduction at room temperature and mild pressures

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    ABSTRACT: Carbon capture and utilization technologies (CCU) and electrolytic hydrogen production are closely interconnected technologies and necessary for a sustainable energy system. This work describes the development of a process for room temperature co-electrolysis of CO2 and water to produce syngas, at mild pressures. The influence of several parameters in the performance of the process is reported.N/

    Metodologias de extração e avaliação semi quantitativa da expressão de genes de metabolismo secundário do milho (Zea mays L.).

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    Electrochemical production of syngas from CO2 at pressures up to 30 bar in electrolytes containing ionic liquid

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    ABSTRACT: Electrochemical CO2 reduction in a reactor that can operate up to 100 bar and 80 degrees C, with a configuration similar to that of an alkaline electrolyser, for hydrogen production suitable to be used industrially is reported for the first time. The effect of pressure on the co-electrolysis of CO2 and water was studied. The successful scale-up from a previously reported batch process to electrodes of ca. 30 cm(2) geometrical area (30-fold factor) that combines the use of pressure and an ionic liquid-based electrolyte is presented. Also for the first time, the potential of the system under study to achieve high conversions of CO2 to avoid a purification step of syngas from unreacted CO2 is shown. An inexpensive commercial foil of the common metal zinc was employed. A semi-continuous operation yielded syngas productivities in the range of 0.02-0.04 mmol cm(-2) h(-1) at ca. -1.2 V vs. QRE Ag/Ag+. When an electrolyte consisting of 90 wt% H2O and 10 wt% 1-ethyl-3-methylimidazolium trifluoromethanesulfonate was used, selectivities for CO in the range of 62% to 72% were obtained at 10 bar pressure, whereas selectivities of 82% were obtained at 30 bar pressure. H-2/CO ratios in the range of 1/1 to 4/1 at 10 bar pressure suitable for the synthesis of a variety of fuels, such as hydrocarbons, methanol, methane and chemical building blocks, were observed. An energy efficiency of 44.6% was calculated for a H-2/CO ratio of 2.2 suitable for the synthesis of methanol.info:eu-repo/semantics/publishedVersio
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