186 research outputs found

    Observing Supermassive Black Holes across cosmic time: from phenomenology to physics

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    In the last decade, a combination of high sensitivity, high spatial resolution observations and of coordinated multi-wavelength surveys has revolutionized our view of extra-galactic black hole (BH) astrophysics. We now know that supermassive black holes reside in the nuclei of almost every galaxy, grow over cosmological times by accreting matter, interact and merge with each other, and in the process liberate enormous amounts of energy that influence dramatically the evolution of the surrounding gas and stars, providing a powerful self-regulatory mechanism for galaxy formation. The different energetic phenomena associated to growing black holes and Active Galactic Nuclei (AGN), their cosmological evolution and the observational techniques used to unveil them, are the subject of this chapter. In particular, I will focus my attention on the connection between the theory of high-energy astrophysical processes giving rise to the observed emission in AGN, the observable imprints they leave at different wavelengths, and the methods used to uncover them in a statistically robust way. I will show how such a combined effort of theorists and observers have led us to unveil most of the SMBH growth over a large fraction of the age of the Universe, but that nagging uncertainties remain, preventing us from fully understating the exact role of black holes in the complex process of galaxy and large-scale structure formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and Treves A. (Eds), 2015, Springer International Publishing AG, Cha

    First record of Craspedacusta sowerbii Lankester, 1880 (Hydrozoa, Limnomedusae) in a natural freshwater lagoon of Uruguay, with notes on polyp stage in captivity

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    Abstract The freshwater cnidarian Craspedacusta sowerbii Lankester 1880, has invaded lakes and ponds as well as artificial water bodies throughout the world. The first record in Uruguay corresponding to the jellyfish was made in 1961 in two artificial fountains, with no mention of the polyp form. Although local reports of other related polyp species have been made, information on the benthic form of C. sowerbii is lacking. Here we report the finding of live frustules, solitary individuals, medusae and colonies from a natural lagoon in August 2010, allowing us to observe the morphology and behavior of the polyp stage in captivity. In addition, molecular identification and remarks on the potencial path of introduction are presented. This is the first record in Uruguay of both polyp and medusa stages of C. sowerbii in a natural water body, Del Medio Lagoon (Dpto. de Florida), Uruguay

    The Earth: Plasma Sources, Losses, and Transport Processes

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    This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Mudança organizacional: uma abordagem preliminar

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    Book Reviews

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    Book 1Book Title: Human PhysiologyBook Authors: B.J. Meyer, H.S. Meij &amp; A. C. MeyerIllustrated. R113,00 01AT incl.). Kenwyn: Juta. 1994. ISBN 0-7021-2949-6.Book 2Book Title:  The Urban Health Crisis: Strategies for Health for All in the Face of Rapid UrbanizationBook Author: W.H.O.Pp. xvi + 80. Sw.Fr.20,0/US18,00. Geneva: WHO. 1993. ISBN 92-4-156159-9.Book 3Book Title:  A Guide for Epidemiological Studies of Oral Manifestations of HIV-InfectionBook Authors:  S.L. Melnick, R. Nowjack-Raymer, D. V. Kleinman & P. A. SwangoPp. ix + 27. Sw.Fr.10,00. Geneva: WHO. 1993. ISBN 92-4-154453-8.Book 4Book Title: Neurological EmergenciesBook Author: R.A.C. Hughes (Ed.)Pp. viii + 357. Illustrated. £22,00. London: BMJ. 1994. ISBN 0-7279-0756-5.Book 5Book Title:  Surrogate Motherhood: a Worldwide View of the IssuesBook Author: Diederika PretoriusPp. xxii + 219. 54,75. Illinois: Charles C. Thomas. 9194. ISBN 0-398-05787-7
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