151 research outputs found

    Effects of the Environment on the Properties of Seyfert Galaxies

    Full text link
    We identify 175 Seyfert galaxies from the Southern Sky Redshift Survey - SSRS2. We use the entire SSRS2 catalog to investigate the correlation between the presence of AGN with host environment. The AGN phenomenon is more strongly correlated with the internal host properties, than with the external environment. In particular, we find that Seyferts reside in more luminous galaxies, and are twice as frequent in barred galaxies and systems showing sign of advanced merger condition, when compared to a control sample.Comment: 4 pages, 3 figs, 1 tables, to appear in the proceedings of "The Interplay among Black Holes, Stars and ISM in Galactic Nuclei", IAU 222, eds. T. Storchi Bergmann, L.C. Ho, and H.R. Schmit

    The Seyfert Population in the Local Universe

    Full text link
    The magnitude-limited catalog of the Southern Sky Redshift Survey (SSRS2), is used to characterize the properties of galaxies hosting Active Galactic Nuclei. Using emission-line ratios, we identify a total of 162 (3%) Seyfert galaxies out of the parent sample with 5399 galaxies. The sample contains 121 Seyfert 2 galaxies and 41 Seyfert 1. The SSRS2 Seyfert galaxies are predominantly in spirals of types Sb and earlier, or in galaxies with perturbed appearance as the result of strong interactions or mergers. Seyfert galaxies in this sample are twice as common in barred hosts than the non-Seyferts. By assigning galaxies to groups using a percolation algorithm we find that the Seyfert galaxies in the SSRS2 are more likely to be found in binary systems, when compared to galaxies in the SSRS2 parent sample. However, there is no statistically significant difference between the Seyfert and SSRS2 parent sample when systems with more than 2 galaxies are considered. The analysis of the present sample suggests that there is a stronger correlation between the presence of the AGN phenomenon with internal properties of galaxies (morphology, presence of bar, luminosity) than with environmental effects (local galaxy density, group velocity dispersion, nearest neighbor distance).Comment: 35 pages, 13 figures, Accepted to be publised in Astronomical Journa

    A voz dos bandos: colectivos de justiça e ritos da palavra portuguesa em Timor Leste colonial

    Get PDF
    Este artigo examina as relações entre o discurso da justiça e a prática do ritual nos bandos do governo colonial português em Timor Leste, entre a segunda metade do século XIX e as primeiras décadas do século XX. Os bandos consistiam em ordens e instruções de comando emanadas pelo governador português em Díli, e comunicadas de forma cerimonial por oficiais às populações dos diversos reinos timorenses dispersos pelo país. Bandos eram um instrumento por excelência de governação colonial dos assuntos indígenas, servindo para arbitrar conflitos, punir transgressões e, em geral, instituir realidades no mundo timorense. Contudo, esta instituição assumiu igualmente uma singular expressão nos usos timorenses, servindo bandos para comunicar também as ordens de autoridades tradicionais, os liurais. O artigo acompanha as variações coloniais e indígenas que os bandos adquiriram em Timor Leste, conceptualizando-os enquanto colectivos de justiça. Ao considerar assim os bandos como colectivos – formações heterogéneas em que elementos linguísticos e não linguísticos se combinam na produção de efeitos de poder sobre as populações – o artigo propõe uma via conceptual alternativa às perspectivas linguísticas e literárias de análise do discurso colonial

    EpIG‐DB: A database of vascular epiphyte assemblages in the Neotropics

    Get PDF
    Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil‐rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large‐scale distribution patterns. EpIG‐DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG‐DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevés (host trees and ‘understory’ plots). EpIG‐DB reports the occurrence of ‘true’ epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up‐to‐date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG‐DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG‐DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes

    Geographical Variability in the Likelihood of Bloodstream Infections Due to Gram-Negative Bacteria: Correlation with Proximity to the Equator and Health Care Expenditure (vol 9, e114548, 2014)

    Get PDF
    Hosp Univ Austral, Div Infect Dis Prevent & Infect Control Serv, Buenos Aires, DF, ArgentinaHosp Univ Austral, Microbiol Lab, Buenos Aires, DF, ArgentinaMonash Hlth, Monash Infect Dis, Clayton, Vic, AustraliaWollongong Hosp, Wollongong, NSW, AustraliaUniversidade Federal de São Paulo, Div Infect Dis, Lab Especial Microbiol Clin, São Paulo, BrazilHosp Israelita Albert Einstein, São Paulo, BrazilVirginia Commonwealth Univ, Med Ctr, Richmond, VA USAHosp Rim & Hipertensao, São Paulo, BrazilHosp Santa Casa Porto Alegre, Porto Alegre, RS, BrazilHosp Conceicao, Porto Alegre, RS, BrazilHosp Walter Cantidio, Fortaleza, Ceara, BrazilHosp Diadema, São Paulo, BrazilHosp Espanhol, Salvador, BA, BrazilHosp Clin Goiania, Goiania, Go, BrazilMt Sinai Hosp, Toronto, ON M5G 1X5, CanadaUniv Alberta, Div Infect Dis, Edmonton, AB, CanadaCairo Univ Kasr Ainy, Dar Al Fouad Hosp, Fac Med, Dept Clin Pathol, Cairo, EgyptHygeia Gen Hosp, Athens, GreeceUniv Tubingen Hosp, Internal Med, Div Infect Dis, Tubingen, GermanyTokyo Metropolitan Tama Med Ctr, Dept Infect Prevent, Tokyo, JapanAmphia Hosp Breda, Lab Microbiol & Infect Control, Breda, NetherlandsThammasat Univ Hosp, Div Infect Dis, Pathum Thani, ThailandSt John Hosp & Med Ctr, Infect Prevent & Control Dept, Grosse Pointe Woods, MI USAUniv Hosp Bern, Dept Infect Dis, CH-3010 Bern, SwitzerlandUniv Bern, Bern, SwitzerlandBarnes Jewish Hosp, St Louis, MO 63110 USAUniversidade Federal de São Paulo, Div Infect Dis, Lab Especial Microbiol Clin, São Paulo, BrazilWeb of Scienc

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

    Get PDF
    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types
    corecore