First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e

To date, infrared interferometry at best achieved contrast ratios of a few times $10^{-4}$ on bright targets. GRAVITY, with its dual-field mode, is now capable of high contrast observations, enabling the direct observation of exoplanets. We demonstrate the technique on HR8799, a young planetary system composed of four known giant exoplanets. We used the GRAVITY fringe tracker to lock the fringes on the central star, and integrated off-axis on the HR8799e planet situated at 390 mas from the star. Data reduction included post-processing to remove the flux leaking from the central star and to extract the coherent flux of the planet. The inferred K band spectrum of the planet has a spectral resolution of 500. We also derive the astrometric position of the planet relative to the star with a precision on the order of 100$\,\mu$as. The GRAVITY astrometric measurement disfavors perfectly coplanar stable orbital solutions. A small adjustment of a few degrees to the orbital inclination of HR 8799 e can resolve the tension, implying that the orbits are close to, but not strictly coplanar. The spectrum, with a signal-to-noise ratio of $\approx 5$ per spectral channel, is compatible with a late-type L brown dwarf. Using Exo-REM synthetic spectra, we derive a temperature of $1150\pm50$\,K and a surface gravity of $10^{4.3\pm0.3}\,$cm/s$^{2}$. This corresponds to a radius of $1.17^{+0.13}_{-0.11}\,R_{\rm Jup}$ and a mass of $10^{+7}_{-4}\,M_{\rm Jup}$, which is an independent confirmation of mass estimates from evolutionary models. Our results demonstrate the power of interferometry for the direct detection and spectroscopic study of exoplanets at close angular separations from their stars.Comment: published in A&

Amelogênese imperfeita desencadeia problemas estéticos e funcionais

A amelogênese imperfeita é uma alteração de caráter genético que afeta o esmalte dentário dos dentes temporários e permanentes. Pode provocar, como consequência, hipersensibilidade dentária, perda da dimensão vertical e comprometimento a nível estético. A intenção com este trabalho é identificar e descrever os aspectos clínicos e os possíveis tratamentos para a anomalia. O processo de formação do esmalte dentário conta com três etapas principais: deposição da matriz orgânica, mineralização da matriz e a maturação do esmalte. Uma falha em qualquer destes estágios determinada geneticamente pode gerar alguma anomalia. O fenótipo apresentado depende do gene afetado, da localização, do tipo de mutação e da proteína acometida. Assim, podem estar afetados os genes responsáveis por 90% da transcrição da amelogenina, enamelina e calicreína. Esses defeitos na formação do esmalte podem ser divididos ao longo desses processos, criando quatro padrões principais: hipoplásico, hipomaturado, hipocalcificado e hipomaturado-hipoplásico. Alterações ocasionadas na fase de deposição da matriz orgânica são chamadas hipoplásicas, as que ocorrem durante o período de mineralização são hipomaturas e, na fase de mineralização do esmalte, são as hipocalcificadas. Em um tratamento adequado é importante diagnosticar e classificar corretamente essas alterações. Parte de um plano complexo de restauração depende da severidade da condição, podendo existir uma inter-relação de disciplinas, combinando terapia ortodôntica, cirurgia ortognática, cirurgia periodontal, prótese dental, múltiplas extrações dentárias, restaurações estéticas, confecção de coroas, próteses, sendo sempre necessária uma boa higiene oral para o sucesso do tratamento. O tratamento é complexo em estágios avançados de destruição da estrutura dentária. O planejamento e a escolha da melhor alternativa de tratamento dependem do nível socioeconômico, faixa etária e gravidade da anomalia do paciente. Contudo, é possível restabelecer a funcionalidade e a estética dental, assim, um bom tratamento intervém positivamente na autoestima e no comportamento dos pacientes.Palavras-chave: Amelogênese imperfeita. Odontologia. Estética dental

Hemostasia e tendência hemorrágica em pacientes odontológicos

É comum os cirurgiões-dentistas depararem-se com pacientes que possuem tendência hemorrágica, portanto é imprescindível o conhecimento sobre os mecanismos da hemostasia. Trata-se de um processo fisiológico cuja finalidade é manter o sangue em estado fluído dentro dos vasos sanguíneos quando lesionados. O objetivo com este trabalho é conhecer o processo hemostático e seus mecanismos e aplicá-los corretamente no exercício da profissão odontológica. Trata-se de uma revisão de literatura cujo levantamento bibliográfico foi baseado em artigos da base de dados SciELO e em livros de fisiologia humana. Para estancar o sangramento em casos de injúrias, os mecanismos da hemostasia devem ser ativados. Logo que o traumatismo vascular é causado ocorre a vasoconstrição por meio da contração da musculatura lisa, diminuindo o fluxo sanguíneo. Em seguida as plaquetas são ativadas e agregam-se ao local da lesão, aderindo umas às outras e formando um tampão plaquetário. Simultaneamente, a cascata de coagulação é ativada por meio da via intrínseca, que ocorre no interior dos vasos sanguíneos, e da via extrínseca, na qual o sangue extravasa dos vasos para os tecidos conjuntivos. Essas vias convergem para uma via comum, resultando na etapa final da coagulação, na qual é ativada a protrombina em trombina, e o fibrinogênio em rede de fibrina, formando um coágulo para o preenchimento da lesão. Após o reparo da parede vascular ocorre a fibrinólise, processo no qual o coágulo é dissolvido pela plasmina por meio da digestão da rede de fibrina. Quando práticas clínicas são realizadas é necessário que o odontólogo faça perguntas aos pacientes sobre sangramento, cicatrização de ferimentos e uso de medicamentos. Caso haja suspeita de tendência hemorrágica é necessário auxílio de exames laboratoriais para mostrar a contagem de plaquetas, os tempos de sangramento, coagulação, protrombina e tromboplastina parcial ativada. Posteriormente, exames especiais mostrarão quais os procedimentos que deverão tomados.Palavras-chave: Hemostasia. Coagulação. Tampão plaquetário. Fibrinólise. Lesão vascular.

Accretion-ejection morphology of the microquasar SS 433 resolved at sub-au scale

This is the author accepted manuscript. the final version is available from EDP Sciences via the DOI in this recordWe present the first optical observation of the microquasar SS 433 at sub-milliarcsecond (mas) scale obtained with the GRAVITY instrument on the Very Large Telescope interferometer (VLTI). The 3.5-h exposure reveals a rich K-band spectrum dominated by hydrogen Brγand He i lines, as well as (red-shifted)emission lines coming from the jets. The K-band-continuum-emitting region is dominated by a marginally resolved point source (<1 mas) embedded inside a diffuse background accounting for 10% of the total flux. The jet line positions agree well with the ones expected from the jet kinematic model, an interpretation also supported by the consistent sign (i.e., negative/positive for the receding/approaching jet component) of the phase shifts observed in the lines. The significant visibility drop across the jet lines, together with the small and nearly identical phases for all baselines, point toward a jet that is offset by less than 0.5 mas from the continuum source and resolved in the direction of propagation, with a typical size of 2 mas. The jet position angle of ~80° is consistent with the expected one at the observation date. Jet emission so close to the central binary system would suggest that line locking, if relevant to explain the amplitude and stability of the 0.26c jet velocity, operates on elements heavier than hydrogen. The Brγprofile is broad and double peaked. It is better resolved than the continuum and the change of the phase signal sign across the line on all baselines suggests an East-West-oriented geometry similar to the jet direction and supporting a (polar) disk wind origin.Centre National d’Etudes Spatiales (CNES)Programme National Hautes Energies (PNHE)Humboldt FoundationNAS

Phosphodiesterase-5 inhibitors have distinct effects on the hemodynamics of the liver

<p>Abstract</p> <p>Background</p> <p>The NO - cGMP system plays a key role in the regulation of sinusoidal tonus and liver blood flow with phosphodiesterase-5 (PDE-5) terminating the dilatory action of cGMP. We, therefore, investigated the effects of PDE-5 inhibitors on hepatic and systemic hemodynamics in rats.</p> <p>Methods</p> <p>Hemodynamic parameters were monitored for 60 min. after intravenous injection of sildenafil and vardenafil [1, 10 and 100 μg/kg (sil1, sil10, sil100, var1, var10, var100)] in anesthetized rats.</p> <p>Results</p> <p>Cardiac output and heart rate remained constant. After a short dip, mean arterial blood pressure again increased. Systemic vascular resistance transiently decreased slightly. Changes in hepatic hemodynamic parameters started after few minutes and continued for at least 60 min. Portal (var10 -31%, sil10 -34%) and hepatic arterial resistance (var10 -30%, sil10 -32%) decreased significantly (p < 0.05). At the same time portal venous (var10 +29%, sil10 +24%), hepatic arterial (var10 +34%, sil10 +48%), and hepatic parenchymal blood flow (var10 +15%, sil10 +15%) increased significantly (p < 0.05). The fractional liver blood flow (total liver flow/cardiac output) increased significantly (var10 26%, sil10 23%). Portal pressure remained constant or tended to decrease. 10 μg/kg was the most effective dose for both PDE-5 inhibitors.</p> <p>Conclusion</p> <p>Low doses of phosphodiesterase-5 inhibitors have distinct effects on hepatic hemodynamic parameters. Their therapeutic use in portal hypertension should therefore be evaluated.</p

How useful are volunteers for visual biodiversity surveys? An evaluation of skill level and group size during a conservation expedition

The ability of volunteers to undertake different tasks and accurately collect data is critical for the success of many conservation projects. In this study, a simulated herpetofauna visual encounter survey was used to compare the detection and distance estimation accuracy of volunteers and more experienced observers. Experience had a positive effect on individual detection accuracy. However, lower detection performance of less experienced volunteers was not found in the group data, with larger groups being more successful overall, suggesting that working in groups facilitates detection accuracy of those with less experience. This study supports the idea that by optimizing survey protocols according to the available resources (time and volunteer numbers), the sampling efficiency of monitoring programs can be improved and that non-expert volunteers can provide valuable contributions to visual encounter-based biodiversity surveys. Recommendations are made for the improvement of survey methodology involving non-expert volunteers

The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-Au resolution

This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Aims. To investigate the inner regions of protoplanetary discs, we performed near-infrared interferometric observations of the classical T Tauri binary system S CrA. Methods. We present the first VLTI-GRAVITY high spectral resolution (R - 4000) observations of a classical T Tauri binary, S CrA (composed of S CrAN and S CrAS and separated by -10:04), combining the four 8m telescopes in dual-field mode. Results. Our observations in the near-infrared K-band continuum reveal a disc around each binary component, with similar halfflux radii of about 0.1 au at d - 130 pc, inclinations (i = 28 - 3-and i = 22 - 6-), and position angles (PA = 0- 6- and PA = -2-12-), suggesting that they formed from the fragmentation of a common disc. The S CrAN spectrum shows bright He i and Br line emission exhibiting inverse P Cygni profiles, typically associated with infalling gas. The continuum-compensated Br line visibilities of S CrAN show the presence of a compact Br emitting region whose radius is about -0.06 au, which is twice as big as the truncation radius. This component is mostly tracing a wind. Moreover, a slight radius change between the blue-And red-shifted Br line components is marginally detected. Conclusions. The presence of an inverse P Cygni profile in the He i and Br lines, along with the tentative detection of a slightly larger size of the blue-shifted Br line component, hint at the simultaneous presence of a wind and magnetospheric accretion in S CrA N.Science Foundation IrelandAlexander von Humboldt Foundation Fellowship ProgrammeFrench PNPSLabEx OSUG@202

Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole

This is the author accepted manuscript. the final version is available from EDP Sciences via the DOI in this recordThe highly elliptical, 16-year-period orbit of the star S2 around the massive black hole candidate Sgr A∗ is a sensitive probe of the gravitational field in the Galactic centre. Near pericentre at 120 AU ≈ 1400 Schwarzschild radii, the star has an orbital speed of ≈ 7650 km s-1, such that the first-order effects of Special and General Relativity have now become detectable with current capabilities. Over the past 26 years, we have monitored the radial velocity and motion on the sky of S2, mainly with the SINFONI and NACO adaptive optics instruments on the ESO Very Large Telescope, and since 2016 and leading up to the pericentre approach in May 2018, with the four-telescope interferometric beam-combiner instrument GRAVITY. From data up to and including pericentre, we robustly detect the combined gravitational redshift and relativistic transverse Doppler effect for S2 of z = Δλ / λ ≈ 200 km s-1/c with different statistical analysis methods. When parameterising the post-Newtonian contribution from these effects by a factor f, with f = 0 and f = 1 corresponding to the Newtonian and general relativistic limits, respectively, we find from posterior fitting with different weighting schemes f = 0.90 ± 0.09|stat ± 0.15|sys. The S2 data are inconsistent with pure Newtonian dynamics

11q13 amplification status and human papillomavirus in relation to p16 expression defines two distinct etiologies of head and neck tumours

Two distinct etiologies of head and neck squamous cell carcinoma (HNSCC) have been proposed, DNA damage owing to tobacco and alcohol exposure and human papillomavirus (HPV) oncogene-mediated transformation. Common genetic alterations in HNSCC include TP53 mutations, 11q13 amplification (amp) and CDKN2A/p16 mutations or promoter methlyation. However, in HPV+ HNSCC it is frequent to observe wild-type TP53 and expression of p16. The relationship of this unusual pattern with 11q13 amp has not been tested. In a retrospective study on 125 HNSCC patients, only 17% (five out of 30) of HPV+ vs 44% (39 out of 89) of HPV − tumours expressed 11q13 amp (adjusted odds ratio (OR)=0.2, 95% confidence interval (CI)=0.1–0.6). A subpopulation of tumours (n=69) were classified according to the three molecular markers, TP53, p16 and 11q13 amp. In addition to wild-type TP53, and p16 expression, HPV+ tumours were more likely not to be amplified at 11q13 (OR=6.5, 95% CI=1.8–23.9). As HPV+ HNSCC lack the genetic alterations which are common in other tumours, we hypothesise that HPV infection may represent an early event in the HNSCC carcinogenic process, thus suggesting a distinct molecular pathway