Non-axisymmetric accretion on the classical TTS RW Aur A

(Abridged) High-resolution spectroscopic monitoring of RW Aur A was carried out in 1996, 1998 and 1999 with simultaneous B, V photometry. A multicomponent spectrum is revealed with a veiled photospheric spectrum, broad emissions, narrow emission lines of helium, and accretion, wind and shell features. Periodic modulations in many spectral features were found. The photospheric absorption lines show sinusoidal variations in radial velocity with an amplitude of +-6 km/s and a period of about 2.77 days. The radial velocities of the narrow emission lines of He vary with the same period but in anti-phase to the photospheric lines. The equivalent widths of the narrow emissions vary with a phase-shift with respect to the velocity curve. The strength of the red-shifted accretion components of Na D and other lines is also modulated with the same period. The broad emission lines of metals vary mostly with the double period of about 5.5 days. One unexpected result is that no correlation was found between the veiling and the brightness, although both varied in wide ranges. This is partly due to a contribution of the shell absorption to the photospheric line profiles, which make them vary in width and depth thus simulating lower veiling. Most of the observed features can be interpreted in the framework of non-axisymmetric magnetospheric accretion. We consider two possible models. In the first the asymmetry is induced by orbital motion of an invisible, low mass secondary, which also influences the gasflows around the star, the second considers rotational modulation of a single star with an inclined or asymmetric magnetosphere

No evidence for mass segregation in massive young clusters

Aims. We investigate the validity of the mass segregation indicators commonly used in analysing young stellar clusters. Methods. We simulate observations by constructing synthetic seeing-limited images of a 1000 massive clusters (10^4 Msun) with a standard IMF and a King-density distribution function. Results. We find that commonly used indicators are highly sensitive to sample incompleteness in observational data and that radial completeness determinations do not provide satisfactory corrections, rendering the studies of radial properties highly uncertain. On the other hand, we find that, under certain conditions, the global completeness can be estimated accurately, allowing for the correction of the global luminosity and mass functions of the cluster. Conclusions. We argue that there is currently no observational evidence of mass segregation in young compact clusters since there is no robust way to differentiate between true mass segregation and sample incompleteness effects. Caution should then be exercised when interpreting results from observations as evidence of mass segregation.Comment: 10 pages, 12 figures, typos corrected. Download a high-resolution version at http://www.astro.up.pt/~jascenso/mseg_v2.pdf (1 MB

Interpreting physical performance in professional soccer match-play: Should we be more pragmatic in our approach?

Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine: a) the association between competitive physical performance and ‘success’ in professional soccer, b) current approaches to interpreting differences in time-motion analysis data across playing positions and, c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified

Pollutants make rheumatic diseases worse: Facts on polychlorinated biphenyls (PCBs) exposure and rheumatic diseases

Background Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate in adipose tissue, disturbing its metabolism and the balance of adipokines, related to obesity. The altering secretion pattern of adipokines from the adipose tissue and the increasing mechanical load in weight-bearing joints presented in obesity condition, are risk factors for osteoarthritis development. The most prevalent rheumatic diseases, osteoarthritis and rheumatoid arthritis, are chronic conditions that target the whole joints, leading to increasing disability and health care cost. The goal of this focused review is to summarize the current knowledge on the role of PCBs in osteoarthritis and rheumatoid arthritis pathogenesis. Search strategy A PubMed search was managed using keywords as “rheumatic diseases”, “polychlorinated biphenyls”, “obesity” and “endocrine disruption”. Main results of the review The incidence of rheumatoid arthritis has been reported to be increased especially in urban areas in industrialized countries, emphasizing the importance of environment in the pathogenesis of rheumatic diseases. Analysis of two cohorts exposed to PCBs food contamination showed high incidence of arthritis. In addition, PCBs in serum correlated positively with the prevalence of self-reported arthritis. Few studies support the hypothesis that osteoarthritis development could be related to PCBs induction of chondrocytes apoptosis. Conclusion Evidences have emerged for a relationship between PCBs and development of several types of arthritis. Further research is encouraged to determine the correlation between PCBs exposure and the development of rheumatic diseases

Famílias e modos de vida: gênero, gerações e identidade

Este artigo discute alguns conceitos, em função de seu uso multidisciplinar e pela forma como têm sido utilizados nesta linha de pesquisa. A seguir, tece comentários sobre resultados de trabalhos de campo, realizados através de método etnográfico e centrados na investigação das trajetórias de sujeitos, no processo de urbanização da Ilha de Santa Catarina

Transition between Variscan and Alpine cycles in the Pyrenean-Cantabrian Mountains (N Spain): Geodynamic evolution of near-equator European Permian basins

In the northern Iberian Peninsula, the Pyrenean-Cantabrian orogenic belt extends E-W for ca. 1000 km between the Atlantic Ocean and Mediterranean Sea. This orogen developed from the collision between Iberia and Eurasia, mainly in Cenozoic times. Lower-middle Permian sediments crop out in small, elongated basins traditionally considered independent from each other due to misinterpretations on incomplete lithostratigraphic data and scarce radiometric ages. Here, we integrate detailed stratigraphic, sedimentary, tectonic, paleosol and magmatic data from well-dated lithostratigraphic units. Our data reveal a similar geodynamic evolution across the Pyrenean-Cantabrian Ranges at the end of the Variscan cycle. Lower-middle Permian basins started their development under an extensional regime related to the end of the Variscan Belt collapse, which stars in late Carboniferous times in the Variscan hinterland. This orogenic collapse transitioned to Pangea breakup at the middle Permian times in the study region. Sedimentation occurred as three main tectono-sedimentary extensional phases. A first phase (Asselian-Sakmarian), which may have even started at the end of the Carboniferous (Gzhelian) in some sections, is mainly represented by alluvial sedimentation associated with calc-alkaline magmatism. A second stage (late Artinskian-early Kungurian), represented by al-luvial, lacustrine and palustrine sediments with intercalations of calc-alkaline volcanic beds, shows a clear up-ward aridification trend probably related to the late Paleozoic icehouse-greenhouse transition. The third and final stage (Wordian-Capitanian) comprised of alluvial deposits with intercalations of alkaline and mafic beds, rarely deposited in the Cantabrian Mountains, and underwent significant pre-and Early Mesozoic erosion in some segments of the Pyrenees. This third stage can be related to a transition towards the Pangea Supercontinent breakup, not generalized until the Early/Middle Triassic at this latitude because the extensional process stopped about 10 Myr (Pyrenees) to 30 Myr (Cantabrian Mountains). When compared to other well-dated basins near the paleoequator, the tectono-sedimentary and climate evolution of lower-middle Permian basins in Western and Central Europe shows common features. Specifically, we identify coeval periods with magmatic activity, extensional tectonics, high subsidence rates and thick sedi-mentary record, as well as prolonged periods without sedimentation. This comparison also identifies some evolutionary differences between Permian basins that could be related to distinct locations in the hinterland or foreland of the Variscan orogen. Our data provide a better understanding of the major crustal re-equilibration and reorganization that took place near the equator in Western-Central Europe during the post-Variscan period

Metabolic control of T cell immune response through glycans in inflammatory bowel disease

Mucosal T lymphocytes from patients with ulcerative colitis (UC) were previously shown to display a deficiency in branched N-glycosylation associated with disease severity. However, whether this glycosylation pathway shapes the course of the T cell response constituting a targeted-specific mechanism in UC remains largely unknown. In this study, we demonstrated that metabolic supplementation of ex vivo mucosal T cells from patients with active UC with N-acetylglucosamine (GlcNAc) resulted in enhancement of branched N-glycosylation in the T cell receptor (TCR), leading to suppression of T cell growth, inhibition of the T helper 1 (Th1)/Th17 immune response, and controlled T cell activity. We further demonstrated that mouse models displaying a deficiency in the branched N-glycosylation pathway (MGAT5-/-, MGAT5+/-) exhibited increased susceptibility to severe forms of colitis and early-onset disease. Importantly, the treatment of these mice with GlcNAc reduced disease severity and suppressed disease progression due to a controlled T cell-mediated immune response at the intestinal mucosa. In conclusion, our human ex vivo and preclinical results demonstrate the targeted-specific immunomodulatory properties of this simple glycan, proposing a therapeutic approach for patients with UC.We thank Dr. Hiroaki Korekane and Fumi (RIKEN) for support in preparation of the fluorescent oligosaccharide acceptor substrate. We thank Dr. Michael Pierce for kindly providing the MGAT5 knockout mice. We also thank Paula Paíga (REQUIMTE/LAQV) for technical support with the HPLC system. The Institute of Molecular Pathology and Immunology of the University of Porto integrates the i3S research unit, which is partially supported by the Portuguese Foundation for Science and Technology (FCT). This article is a result of the project NORTE-01-0145-FEDER-000029, supported by the Norte Portugal Regional Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund. This work was also funded by Fundo Europeu de Desenvolvimento Regional (FEDER) funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through the FCT in the framework of the project (POCI-01/ 0145-FEDER-016601 and PTDC/DTP-PIC/0560/2014). S.S.P. acknowledges the European Crohn’s and Colitis Organization (ECCO) for ECCO Grant 2017, the Broad Medical Research Program at the Crohn’s and Colitis Foundation of America, and the Portuguese Group of Study in IBD (GEDII) for funding. A.M.D. [PD/BD/105982/2014], A.C. [SFRH/BPD/91623/2012], and M.S.P. [SFRH/ BD/110148/2015] received funding from the FCT. M. Lima thanks the CHP for the research support.info:eu-repo/semantics/publishedVersio

New lithostratigraphy for the Cantabrian Mountains: A common tectono-stratigraphic evolution for the onset of the Alpine cycle in the W Pyrenean realm, N Spain

The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary phases of the western Peri-Tethys basins. Through detailed field work, including geological mapping, sedimentology, lithostratigraphy and petrology of volcanic rocks, and new palaeontological data, here we define several new lithostratigraphical formations and five new tectono-sedimentary cycles (TS I-V) for the initial phases of evolution of the Mesozoic Basque-Cantabrian Basin, interrupted by periods of tectonic stability. To complete this information, we include data from an onshore borehole (Villabona Mine) and two offshore boreholes constrained by 2D reflection seismic profiles acquired in the North Iberian continental platform. The main tectono-sedimentary cycles, related to the deposition of five major identified lithostratigraphic units, can be described as follows: TS I (late Gzelian-early Asselian), relating to the late Variscan deformation and preserved in a single outcrop in all the Cantabrian Mountains (San Tirso Formation). This formation is constituted by medium-distal alluvial fan deposits in which humid intervals predominate, forming some thin coal beds. TS II (Asselian-Sakmarian), a post-Variscan extensional phase with associated calc-alkaline magmatism, represented by profuse volcanic and volcanosedimentary intercalations in the early Permian sedimentary basins (Acebal Formation) and small plutons in surrounding areas. TS III (Kungurian), or reactivation of the post-Variscan extension leading to alluvial and lacustrine carbonate sedimentation in arid climate conditions, which do not change during the rest of the Permian and Triassic periods (Sotres Formation). A generalized karstification in the basin represents the end of Permian deposition, followed by an interruption in sedimentation longer than 30 Myr. The Permian tectono-sedimentary cycles (TS II and TS III) are contemporary with Variscan belt collapse and the basins are controlled by extensional reactivation of NE-SW and E-W Variscan structures, and NW-SE late Variscan structures. TS IV (late Anisian–middle Carnian), renewed sedimentation in more extensive basins, precursors of the great Mesozoic Basque-Cantabrian Basin. This cycle is represented by fluvial deposits (Cicera Formation, or Buntsandstein facies), which are interrupted by the first Mesozoic marine ingression (Rueda Formation, or Muschelkalk facies). TS V (Norian-Rhaetian), or shallow marine carbonate deposits (Transición Formation) related to increasingly compartmentalized sub-basins, controlled by normal faults. This final TS is broadly connected with different basins of the western Peri-Tethys domain. The identification of units TS I-V in the Cantabrian Mountains along with the volcanic character of TS II, all indicate the development of a common post-Variscan to early Alpine tectono-sedimentary evolution for the whole Pyrenean-Cantabrian realm

Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV

We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/- 0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.Comment: Accepted for publication by PR