14 research outputs found

    The Jovian Magnetosphere And Magnetopause

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    It is convenient to divide the magnetosphere into three regions. The inner magnetosphere extends from the surface to about 25 R_J and is dominated by the basically dipolar field. The outer magnetosphere, on the sunward side, occupies a layer roughly 15 R_J thick just inside the magnetopause. Here the field direction was found by Pioneers 10 and 11 to have a strong southward component, 5 to 10 times as strong as expected if one scales the observations in the Earth’s magnetosphere. The middle magnetosphere is the remaining region. Its thickness, again on the sunward side, varies greatly as the magnetopause moves in and out. In this region the field direction turns as one goes outward from nearly dipolar to nearly radial but with a persistent southward component. The field is outward in the northern hemisphere, inward in the southern, separated by a thin (~1 or 2 R_J) warped current sheet in which the magnetic field appears to be very weak and mainly southward

    What makes a planet habitable?

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    This work reviews factors which are important for the evolution of habitable Earth-like planets such as the effects of the host star dependent radiation and particle fluxes on the evolution of atmospheres and initial water inventories. We discuss the geodynamical and geophysical environments which are necessary for planets where plate tectonics remain active over geological time scales and for planets which evolve to one-plate planets. The discoveries of methane–ethane surface lakes on Saturn’s large moon Titan, subsurface water oceans or reservoirs inside the moons of Solar System gas giants such as Europa, Ganymede, Titan and Enceladus and more than 335 exoplanets, indicate that the classical definition of the habitable zone concept neglects more exotic habitats and may fail to be adequate for stars which are different from our Sun. A classification of four habitat types is proposed. Class I habitats represent bodies on which stellar and geophysical conditions allow Earth-analog planets to evolve so that complex multi-cellular life forms may originate. Class II habitats includes bodies on which life may evolve but due to stellar and geophysical conditions that are different from the class I habitats, the planets rather evolve toward Venus- or Mars-type worlds where complex life-forms may not develop. Class III habitats are planetary bodies where subsurface water oceans exist which interact directly with a silicate-rich core, while class IV habitats have liquid water layers between two ice layers, or liquids above ice. Furthermore, we discuss from the present viewpoint how life may have originated on early Earth, the possibilities that life may evolve on such Earth-like bodies and how future space missions may discover manifestations of extraterrestrial life

    Investigation of Enteric Viruses in the Feces of Neotropical Migratory Birds Captured on the Coast of the State of Pará, Brazil

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    Made available in DSpace on 2018-12-11T16:53:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01. Added 1 bitstream(s) on 2019-10-09T18:29:42Z : No. of bitstreams: 1 S1516-635X2018000100161.pdf: 376041 bytes, checksum: 32723ae502ce34e68b81829514936c67 (MD5)Migratory birds can become long-distance vectors for a wide range of microorganisms and can cause human disease, being the Brazilian coast a gateway for northern migratory birds. These animals are considered natural reservoirs of different viruses that cause important diseases, being relevant research of viral pathogens in migratory birds to epidemiology surveillance. The objective of the study was to investigate the presence of avian rotavirus (AvRV), avian reovirus (ARV) and picobirnavirus (PBV) in Neotropical migratory birds captured on the coast of Brazil. A total of 23 individual fecal samples of the migratory birds species Calidris pusilla (20 birds), Numenius phaeopus (1 bird) and Charadrius semipalmatus (2 birds) were collected. Fecal suspensions were prepared from the collected samples for subsequent extraction of double-stranded RNA (dsRNA), which was subjected to polyacrylamide gel electrophoresis (PAGE) and reverse transcription polymerase chain reaction (RT-PCR). The electrophoretic profiles were not detected by PAGE, and the amplification for the studied viruses PBV, ARV and AvRV (specie D, gene VP6 and NSP4) were negative. Positivity for AvRVD, VP7 gene was of 4.35% (1/23) for the migratory bird Calidris pusilla. After sequencing and building the tree of phylogenetic relationships avian Rotavirus Group D identified in this study was phylogenetically related and grouped into one branch, together to previously reported AvRVD from Brazil in chicken flocks with 99.8% nucleotide and 100% amino acid similarities.Laboratório de Zoonoses Faculdade de Medicina Veterinária Universidade Federal do Pará, Campus Castanhal, Rodovia BR-316 Km 62 s/n, SaudadeInstituto Evandro Chagas (IEC), BR-316 Km 7 s/n, Distrito de LevilândiaLaboratório Nacional de Agricultura (Lana-gro/PA) Ministério da Agricultura Pecuária e Abastecimento (MAPA), Av. Almirante Barroso1234, Distrito de MarcoUniversidade Federal Rural da Amazônia (UFRA), Av. Presidente Tancredo Neves 2501Universidade Estadual Paulista (UNESP), Distrito de Rubião Jr. S/NUniversidade Estadual Paulista (UNESP), Distrito de Rubião Jr. S/

    Depression and apathy after transient ischemic attack or minor stroke: prevalence, evolution and predictors

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    Few previous studies have focused on affective impairment after transient ischemic attack (TIA) and/or minor stroke. The aim was to establish the prevalence, evolution and predictors of post-stroke depression (PSD) and post-stroke apathy (PSA) over a 12-month follow-up period. We prospectively included TIA and minor stroke patients (NIHSS ≤4) who had undergone magnetic resonance imaging <7 days. PSD was diagnosed according to DSM-5 criteria and PSA was defined based on an Apathy Evaluation Scale (AES-C) score of ≥37. Clinical and neuroimaging variables (presence and patterns of lesion, cerebral bleeds and white matter disease) were analysed in order to find potential predictors for PSD and PSA. Follow-up was performed at 10 days and after 2, 6, 9 and 12 months. 82 patients were included (mean 66.4 [standard deviation11.0] years) of whom 70 completed the follow-up. At 10 days, 36 (43.9%) and 28 (34.1%) patients respectively were diagnosed with PSD and PSA. At 12 months, 25 of 70 (35.7%) patients still had PSA, but only 6 of 70 (8.6%) had PSD. Beck Depression Inventory-II score, mini mental state examination (MMSE) and a previous history of depression or anxiety were predictors for PSD. While MMSE score, The Montgomery Asberg Depression Rating Scale and having previously suffered a stroke were also risk factors for PSA. Acute basal ganglia lesion and periventricular leukoaraiosis were associated with PSA while deep leukorariosis with PSD. Despite the presence of few or only transient symptoms, PSD and PSA frequent appear early after TIA and minor stroke. Unlike PSD, apathy tends to persist during follow-up
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